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  THE NILE IN 1904

  BY

  Sir WILLIAM WILLCOCKS, K.C.M.G., F.R.G.S.

  LONDON
  E. & F. N. SPON LIMITED, 57 HAYMARKET.

  NEW YORK
  SPON & CHAMBERLAIN, 123 LIBERTY STREET.

  _=Price 9=s/- =net.=_

  PRINTED AT THE NATIONAL PRINTING DEPARTMENT OF EGYPT, CAIRO

  1904.


  _Dedicated to my old Chief and Master in Irrigation, Sir Colin
  Scott-Moncrieff, K.C.S.I., K.C.M.G., under whom I had the privilege of
  working for 20 years in India and Egypt._




PREFACE


The publication of Sir William Garstin’s monumental work on the “Basin
of the Upper Nile” is an event of such importance in the history of the
Nile that the occasion should not be lost of bringing Lombardini’s work
on the Nile to date. The information utilised by me in this book as far
as the Upper Nile is concerned is obtained from Sir William’s Report;
for the Blue Nile and Atbara I am indebted to M. Dupuis’ interesting
appendix at the end of Sir William’s Report; and for the river north of
Khartum to my own studies and surveys. As Sir William employed Capt.
H.G. Lyons, R.E. to collaborate with him, the references to the works of
previous writers and geographical details may be accepted without any
misgivings. To M. Chélu Bey, Director of the Government Press, I am
indebted for his ever ready aid; to Mr. Hansard of the Survey Department
for the plates accompanying this work; and to Mr H.G.F. Beadnell, F.G.S,
F.R.G.S, for having kindly written the description of the Egyptian oases
and the geology of Egypt which form the fifth chapter of this book.

  W. WILLCOCKS.

  _Cairo, 12-10, 1904._




THE NILE IN 1904.


SUBJECT MATTER.


  CHAPTER I. _The Nile_--(Page 11).

   1. Introduction.
   2. Nomenclature.
   3. Description of the course of the Nile.
   4. Slopes and velocities of the Nile in its different reaches.
   5. Catchment basins of the Nile and its tributaries.
   6. The climate of the Nile valley.
   7. The geology of the Nile valley.
   8. The discharges of the Nile and its tributaries.


  CHAPTER II. _The tributaries of the Nile_--(Page 26).

   9. Lake Victoria Nyanza.
  10. The Victoria Nile.
  11. The Semliki river.
  12. Lake Albert Nyanza.
  13. The Albert Nile.
  14. The Gazelle river.
  15. The Zeraf river.
  16. The Sobat river.
  17. The Sudd region.
  18. The White Nile.
  19. The Blue Nile.
  20. The Atbara.
  21. The Nile from Khartoum to Assuân.
  22. The Nile from Assuân to the Barrage.
  23. The Rosetta and Damietta Branches.


  CHAPTER III. _The utilisation of the Nile_--(Page 56).

  24. The Nile in flood.
  25. The Nile in low supply.
  26. Nile water.
  27. The soil of the Nile Valley.
  28. Basin irrigation.
  29. Perennial irrigation.
  30. Flood protection.


  CHAPTER IV. _Projects_--(Page 73).

  31. Projects.
  32. The raising of the Assuân dam.
  33. The Wady Rayan reservoir and escape.
  34. The Albert Lake and Nile project.
  35. Flood protection for Egypt.
  36. Complete project for water storage and flood control.
  37. Sir William Garstin’s projects.
  38. The conversion of basin to perennial irrigation.
  39. Development of the Sudan.


  CHAPTER V. _The oases and the geology of Egypt by H.J.L.
  Beadnell, F.G.S., F.R.G.S._--(Page 107).

  40. The oases.
  41. Dakhla oasis.
  42. Kharga oasis.
  43. Baharia oasis.
  44. Farafra oasis.
  45. The geology of Egypt.
  46. Igneous rocks.
  47. Sedimentary rocks.
  48. Upper cretaceous.
  49. Eocene.
  50. Oligocene and Miocene.
  51. Pliocene, Pleistocene and Recent.
  52. Economic products.


  Table of Appendices (Page 117).


  Index (Page 221).




LIST OF PLATES.

                                                                   PAGE.
      I. Plan of the Nile Valley                                      12
     II. Longitudinal Section of the Nile Valley                      14
    III. Outlet of Lake Victoria                                      26
     IV. Cross sections of the Nile and its tributaries (1)           28
      V. Gauge diagrams of Lakes Victoria and Albert                  30
     VI. The Sudd region                                              34
    VII. Outlet of Tsana Lake                                         44
   VIII. Gauge diagrams of the White and Blue Niles at Khartoum       46
     IX. Cross sections of the Nile and its tributaries (2)           42
      X. Longitudinal section of the Nile: Wady Halfa to Assuân       48
     XI. Cross sections of the Nile and its tributaries (3)           52
    XII. Longitudinal section of the Nile: Assuân to Cairo            50
   XIII. Typical cross sections of the Nile Valley                    50
    XIV. Plan of typical basin irrigation in Egypt                    66
     XV. Plan of the Fayoum and the Wady Rayan                        76
    XVI. Longitudinal section of the Fayoum and the Wady Rayan        80
   XVII.      „          „      „    Rosetta Branch                   54
  XVIII.      „          „      „    Damietta Branch                  54
    XIX. Plan of typical perennial irrigation in Egypt                68
     XX. Possible tunnel at Lake Tsana                               103
    XXI. The Egyptian oases                                          108




THE NILE IN 1904.




CHAPTER I.

The Nile.


1. =Introduction.=--In the introduction to his brilliant essay on the
Hydrology of the Nile[1], an essay, which, though written in 1865,
foreshadowed much of what we know to day, Lombardini remarked, with much
truth that, no river in the world lends itself to hydrological studies
on so majestic a scale as the Nile. The most interesting river of the
ancient world, it is still the most interesting river of our time; and,
in spite of all that ancient and modern discoveries have unfolded, its
discharges are to-day more difficult to unravel and weave together than
those of any other stream in either hemisphere. These discharges are
still a mystery, and it will need years and years of patient observation
and study, at the hands of the Sudan Irrigation Department, to enable us
to state with exactitude why its floods rise and fall with such regular
and stately precision, why they are never sudden and abrupt, and why its
summer supplies can never be completely cut off even in their traverse
of over 3000 kilometres through the burning and parched Sahara. Though
the mystery of the Nile is far from being solved to-day, still an
enormous step in advance has been made by the publication of Sir William
Garstin’s Report on the Basin of the Upper Nile[2]. This Report not only
contains the results of three years’ observations of the Egyptian Survey
Department in the Sudan, of Sir William Garstin’s own observations and
studies, but also a mass of information of the Nile and its tributaries
collected by Capt. H. G. Lyons. R. E., through four years of
uninterrupted study. Those who know the intelligence and method with
which Capt. Lyons works, will rate this information at its proper value.

  [1] _Saggio idrolico sul Nilo_, by ELIA LOMBARDINI, Milan 1865.

  [2] _Report on the Basin of the Upper Nile_ by SIR WILLIAM GARSTIN.
  Blue Book Egypt (2) 1904.

Lombardini gathered together all the information available at the time
that Sir Samuel Baker announced the existence of the Albert Nyanza
shortly after Speke and Grant had proclaimed to the world that the
Victoria Nyanza was the true source of the Nile. From the information
then available he deduced the laws and operations of the great river.
About twenty years later, just before the rebellion in the Sudan closed
the Nile to the civilized world, a German savant, Joseph Chavanne[3], in
his book on the rivers of Africa, collected and tabulated on clear and
methodical lines much of the information available in 1883. Though many
of his facts are erroneous, his method is clear and his ideas just. Sir
William Garstin, in his Report, has developed the information at his
disposal on such practical lines as are needed to study the question of
insuring an abundant supply of water to the Nile in Egypt during the
times of low supply.

  [3] “_Afrikas Ströme und Flüsse_” by JOSEPH CHAVANNE. Wien 1883.

Having myself studied the Nile for fifteen years in order to solve the
problems of water storage and flood control on the Nile, and having
devoted the whole of my life to this very science of Hydraulics, I have
been encouraged to attempt the continuation of Lombardini’s work; and,
to the utmost of my ability, to bring it to the level of the knowledge
of our day.


2. =Nomenclature.=--The nomenclature of the tributaries of the Nile is
difficult to follow. In this book I shall call the river _the Victoria
Nile_ from Lake Victoria to Lake Albert; _the Albert Nile_ from Lake
Albert to the Sobat mouth (this reach is known generally as the Bahr el
Gebel); _the White Nile_ from the Sobat mouth to Khartoum; and _the
Nile_ from Khartoum to the sea. _The Blue Nile_ stretches from Lake
Tsana in Abyssinia to Khartoum.


3. =Description of the course of the Nile.=--Chapters II and III contain
detailed descriptions of the Nile and its main tributaries, and this
paragraph is a short epitome of what is written there about the course
of the Nile. The Nile drains nearly the whole of north-eastern Africa,
an area comprising 3 million square kilometres. Its main tributary, the
White Nile, has its furthest sources in south latitude 4°, near Lake
Tanganyika. Known as the Kagera, it is one of the feeders of Lake
Victoria, and has a course of 600 kilometres before it reaches the lake.
Lake Victoria, covering 60,000 square kilometres, is the first reservoir
of the Nile. The Victoria Nile leaves Lake Victoria by the Ripon Falls
and after a course of 400 kilometres enters Lake Albert at its northern
corner. At its southern end Lake Albert is fed by the Semliki river
which has its sources in Lake Edward. Its own area is 4,500 square
kilometres. The Albert Nile leaves Lake Albert at its northern end and
has a course of 1280 kilometres to the mouth of the Sobat river. Of this
length, the first 200 kilometres up to Dufile have scarcely any slope,
the next 150 kilometres are down a series of severe cataracts. From the
foot of these cataracts to its tail the Albert Nile has a gentle slope
and traverses the Sudd region where the bed of the stream is often
barred by blocks of living vegetation. In this latter region the stream
divides into two, of which the right hand one is known as the Bahr
Zeraf. After a course of 270 kilometres the Bahr Zeraf joins the Albert
Nile again. In the interval the Albert Nile receives as a left-hand
feeder the Bahr Gazelle. The Sobat river has its sources in Gallaland
and joins the Albert Nile at the termination of the Sudd region. From
the junction of the Albert Nile and the Sobat, the river is known as the
White Nile, which, after a course of 840 kilometres, with an exceedingly
gentle slope, joins the Blue Nile at Khartoum.

[Illustration: PLATE I.

THE NILE

Lith. Sur. Dep. Cairo.]

The Blue Nile is the true parent of the land of Egypt. The deposits of
its muddy waters have made Egypt. The Atbara has added its quota, but
the Blue Nile is incomparably the chief contributor; fed by the timely
and plentiful rains of southern and south-eastern Abyssinia, it
contributes 65 per cent of the waters which pass Assuân. The furthest
sources are those of the Abai, which, after a course of 110 kilometres
falls into Lake Tsana. This lake has an area of 3,000 square kilometres
and lies about 1,760 metres above sea level. The Blue Nile leaves it at
its south-eastern corner and hurries down to the Sudan, fed by numerous
Abyssinian rivers. At Rosaires, after a course of 750 kilometres, it has
fallen 1,260 metres; and below the Rosaires cataract enters the plain
country south of Khartoum. For its remaining 615 kilometres on to
Khartoum, where it meets the White Nile, it is navigable for the greater
part of the year. North of Sennaar it is fed by the Dinder and Rahad
rivers.

Between Khartoum and El Damer, on a length of 320 kilometres, the Nile
has its even passage broken by the 6th cataract at Shabluka. At El Damer
the Nile receives the Atbara as a right hand tributary.

The Atbara is a very muddy torrent fed by the rains of north-eastern
Abyssinia. It runs for 4 months per annum and is dry for 8 months.
Rising within a few kilometres of Lake Tsana, it falls 1500 metres in
its first 300 kilometres, and is then joined by the Salaama, and, 100
kilometres lower down, by the Settit river. After the junction with the
Settit, the Atbara flows for 480 kilometres and joins the Nile at El
Damer, contributing a fair quantity of water and a very considerable
quantity of Nile mud to the river.

From the Atbara junction to the sea, the Nile has a course of 2,700
kilometres. In its first length of 1480 kilometres to Assuân it
traverses the 5th and 4th cataracts between Berber and Dongola, the 3rd
and 2nd cataracts between Dongola and Wady Halfa, and the 1st cataract
at Assuân. All these cataracts are navigable in flood, but not so in
summer. From Assuân to the Barrage at the head of the Delta north of
Cairo, the Nile has a length of 970 kilometres and traverses Egypt
without a cataract or interruption of any kind. At the Barrage, the Nile
divides into the Rosetta and Damietta branches, and after a further
course of about 240 kilometres in either branch, flows into the
Mediterranean sea. Its greatest length from the sources of the Kagera
river to the sea is 6350 kilometres, constituting it one of the longest
rivers in the world.


4. =The Slopes and velocities of the Nile in its different
reaches.=--Table 2 of Appendix B and Plate II comprise all the
information available under this head which I have been able to collect.
For the slopes I have adopted the following data:

  R. L. of Lake Victoria      1129 metres above mean sea
     „     Fowera             1060   „          „
     „     Lake Albert         680   „          „
     „     Khartoum (flood)    389   „          „

From Khartoum to Wady Halfa I have adopted the generally accepted levels
of the original Soudan railway survey. From Wady Halfa to the sea I have
levelled myself. Upstream and downstream from the adopted levels I have
carried the levels by the aid of slopes calculated from velocity and
hydraulic mean depth data. It seems to me absurd to adopt a level for
Lake Choga 50 metres above that for Fowera, and then to add, that in the
140 kilometres between the two places the Victoria Nile has a gentle
slope, wide bed and gentle velocity. By a strange fatality, this very
error has crept into the figures under Lake Choga on Plate II. The error
is noted in the corrigenda attached to the Plate. The Section is drawn
correctly but these wrong figures have been interpolated by an
oversight.

The Victoria Nile Falls 450 metres in 400 kilometres, but has four
reaches; the first ¹⁄₁₂₀₀, the second ¹⁄₂₀₀₀₀, the third ¹⁄₁₈₀ past the
Murchison Falls, and the fourth ¹⁄₁₀₀₀₀.

The Albert Nile falls 277 metres in 1290 kilometres. The first reach
past Wadelai has a slope of ¹⁄₂₅₀₀₀, the second over the Fola and
following cataracts has a slope of ¹⁄₇₀₀, the third ¹⁄₁₂₀₀₀, the fourth
¹⁄₂₀₀₀₀, the fifth ¹⁄₂₅₀₀₀, and the last below lake No of ¹⁄₇₅₀₀₀ in
flood.

[Illustration: PLATE II.

  ERRATUM.

  Erase the two figures under Lake Choga in the “Height” column.

LONGITUDINAL SECTION OF THE NILE,

THE BLUE NILE, THE WHITE NILE, THE ALBERT NILE, THE VICTORIA NILE & THE
SEMLIKI RIVER

Lith. Sur. Dep. Cairo.]

The White Nile falls 14 metres in 840 kilometres and has two slopes in
flood; ¹⁄₅₀₀₀₀ in its upper reach, and then ¹⁄₁₀₀₀₀₀.

The Blue Nile falls 1370 metres in 1370 kilometres, which may roughly be
divided into three reaches. The first from Lake Tsana to Rosaires on a
length of 750 kilometres ¹⁄₆₀₀, the second Rosaires to Sennaar ¹⁄₄₅₀₀,
and the third ¹⁄₇₀₀₀. These are very approximate indeed.

The Atbara falls 1640 metres in 880 kilometres. In the first 300
kilometres the slope is ¹⁄₂₀₀; in the next 300 kilometres the slope is
¹⁄₂₅₀₀, and in the last reach of 280 kilometres it is ¹⁄₆₀₀₀. These are
approximate.

The Main Nile from Khartoum to Assuan falls 295 metres in 1810
kilometres; the so-called six cataracts occupy 565 kilometres with a
slope of ¹⁄₃₀₀₀; and the ordinary channel occupies 1245 kilometres and
has a slope of ¹⁄₁₂₀₀₀. From Assuân to the Barrage, on a length of 970
kilometres, the Nile falls 76 metres with a mean slope of ¹⁄₁₃₀₀₀. The
Rosetta and Damietta branches are each about 240 kilometres long and
have a slope in flood of ¹⁄₁₃₀₀₀, and of ¹⁄₁₂₅₀₀ in extraordinarily high
floods.

From the sources of the Kagera river to the sea, on a length of 6350
kilometres, the Nile falls 2000 metres, or has a slope of ¹⁄₃₂₀₀. From
Lake Victoria to the sea the length is 5535 kilometres and the fall 1129
metres, or the slope is ¹⁄₅₀₀₀.

Table III of Appendix C. gives the velocities of the river in flood and
low supply, in metres per second and kilometres per day, and also the
time occupied in traversing the different reaches. There are two breaks.
The first is at Lake Choga and the second is at Lake Albert. As the
Victoria Nile traverses the eastern arm of the many-armed and peculiar
Lake Choga with a perceptible current, and as, moreover, the lake is
very shallow, we may give some figure to the velocity and make it half
that of the Bahr Gazelle which is ·20 metres per second and is
considered perceptible. With a velocity of ·10 metres per second or 8
kilometres per day, the 80 kilometres of the lake would be traversed in
10 days. The time of traverse from Lake Victoria to Lake Albert would be
15 days. With Lake Albert it is very different. A reference to Plate V
will show that it takes the Victoria Nile 5 months to fill up Lake
Albert before the Albert Nile can carry off the waters of the Victoria
Nile, gauge for gauge. Under these conditions it will be wise to stop at
Lake Albert and begin a new calculation from this lake.

The Albert Nile takes 22 days in flood and 25 days in low supply to
traverse the distance from Lake Albert to the Sobat mouth. The White
Nile takes 21 days in flood and 28 days in low supply to reach
Khartoum. Consequently from Lake Albert to Khartoum we have 43 days in
flood and 53 days in low supply.

From Khartoum to Assuân the Nile takes 11 days in flood and 22 days in
low supply, and consequently from Lake Albert to Assuân we have 54 days
in flood and 75 days in low supply.

From Assuân to Cairo we have 6 days in flood and 12 days in low supply.

Table III is very interesting and well worth study. Through the Sudd
region we have a velocity of ·6 metres per second, but only of ·35
metres per second in the White Nile. In Egypt the Nile in flood has a
velocity of 1·75 metres per second, and in low supply of ·85 metres per
second.


5. =Catchment basins of the Nile and its tributaries.=--Table I, of
Appendix A gives the areas of the catchment basins of the Nile. The
total area according to the table is 3,007,000 square kilometres. The
limits of the basin are depicted on Plate I, and, with rare exceptions,
they are now fairly well known everywhere. North of the 20th parallel of
latitude the watershed on the west of the Nile is not far removed from
the edge of the plateau skirting the Nile valley. The plateau falls away
to the west, and occasional ravines find their way to the Nile down the
reverse slope. On the east of the Nile the crest of the hills skirting
the Red sea is the watershed. South of the 20th parallel of latitude the
eastern watershed follows the crest of the hills on the west of the Red
sea as far as Suakin. South of Suakin the watershed leaves the Red sea,
to allow the Khor Barraka to flow into this sea. From the south east of
Kassala, round by Addis Ababa, the watershed follows the crest of the
high hills forming the eastern backbone of Abyssinia, and dividing the
waters of the Nile from those flowing into the Indian Ocean. South west
of Abyssinia the watershed travels in a south-westerly direction to the
east of Gondokoro, and divides the Sobat from the rivers draining into
Lake Rudolf. The watershed then moves due south to the western
escarpment east of Lake Victoria. Mounts Kenia and Kilmanjaro are not
within the basin of the Nile. Sweeping in a rough curve round Lake
Victoria and nearly touching Lake Tangangyika in 4° south latitude, the
watershed keeps close to the western shores of Lakes Edward and Albert
to nearly opposite Wadelai. All the slopes of the Ruenzori mountains
drain into the Nile.

From near Wadelai the watershed moves in a north-westerly direction
along the hills dividing the waters of the tributaries of the Gazelle
river from the Welle. Due west of the Sudd region the watershed has
reached its most westerly position and from there turns northwards along
the Marrah hills in Darfur, dividing the scanty waters of the
Bahr-el-Arab and its tributaries from the rivers draining into Lake
Chad. From the Marrah hills the watershed travels in a north-easterly
direction to a point close to the Nile on the 20th parallel of latitude
near Hannek.

Of the lands enclosed within this watershed, all that are drained
directly into the Main Nile are desert. There are occasional showers,
and some of the valleys and ravines carry water for a few hours every
year, others every second, third or fourth year, but they contribute
practically nothing to the volume of the Nile. The rains generally come
in the winter when the Nile is falling every day, and the steady fall of
the Nile is never arrested by the waters of any or all of these
watercourses. The country west of the White Nile past Kordofan and
Darfur to the Marrah hills is steppe land producing scanty grasses and
forests of low accacias in the south, and rising to a general height of
about 600 metres at the Marrah hills. The lands drained by the Gazelle
river and the Albert Nile north of Gondokoro are flat plains or swamps
in the north and east, and wooded and broken ground in the west and
south-west, where the tributaries of the Gazelle river rise in the Blue
mountains at a general height of 1500 metres. The upper waters of the
Sobat and its tributaries drain the well wooded and cultivated mountain
masses of Gallaland and then traverse the marshes and flat lands which
lie east of the Sudd region. The Blue Nile and its upper tributaries
drain the choicest portions of the high Abyssinian mountain plateau
lying over 2000 metres above sea level, and rising in places to 2500
metres and upwards. The lower courses of the Blue Nile, the Rahad and
the Dinder are through the black cotton soil plains of the eastern
Sudan, which are either wooded or covered with dense grass in the south.
The Atbara and its tributaries in their upper courses drain the northern
slopes of the Abyssinian plateau, and traverse the level plains of the
eastern Sudan in a direction parallel to the Blue Nile.

The Albert Nile and its tributaries between Gondokoro and Lake Albert
traverse the broken and hilly country which is cut through by the Albert
Nile at the Fola and succeeding rapids. The catchment basins of Lakes
Victoria and Albert are the undulating hills, the flat marshy valleys,
the great lakes and, in parts, high hills which constitute the
highlands of Central Africa. The general level of the area may be taken
as 1400 metres above sea level.

The area draining into Lake Victoria is 240,000 square kilometres. At
the outlet of Lake Albert this has increased to 380,000, and at
Gondokoro to 470,000. The Gazelle river drains 470,000 square
kilometres, and the Sobat 160,000. The White Nile drains altogether
1,690,000 square kilometres, or more than half the total area of the
catchment basin of the Nile. The Blue Nile drains 300,000 square
kilometres and the Atbara 240,000. The Nile below the Atbara junction is
draining 2,290,000 square kilometres. Between the Atbara mouth and the
sea, the Nile drains whatever falls on a desert area of 720,000 square
kilometres.

If we take 3,000 cubic metres per second as the average annual flow past
Assuân we may say that the White Nile supplies 24% off more than half
the area of the whole basin, the Blue Nile 65% off ¹⁄₁₀ the area, and
the Atbara 11% off ¹⁄₁₂ the area. The Gazelle river drains about ¹⁄₆ the
total area and adds practically nothing to the discharge. Table 24
should be very carefully studied by any man who wants to understand the
Nile. It does not pretend to exactitude, but embodies the best
information I have been able to obtain.


6. =The climate of the Nile valley.=--This paragraph would have been
much more complete if Capt. Lyons’ monograph on the Meteorology of the
Nile valley had been published. In considering the climate I shall
follow the subdivisions of the catchment basin of the Nile contained in
Table I.

In the catchment basins of Lakes Victoria and Albert, the mean annual
rainfall may be taken as 1.25 metres, with great fluctuations between
good and bad years. Neglecting here and through this paragraph, the
light occasional falls of rain which are trying to travellers but which
have no effect on the rivers, it may be said that in these basins there
are two rainy seasons, the greater in March, April and May, and the
lesser in October, November and December. The former are followed by dry
southern winds, while north winds blow in the winter.

Along the whole of the Albert Nile, the mean annual rainfall may be
taken as 1 metre, with severe famines in occasional years and heavy
rainfall in others. The principal rains are between May and November,
with the maximum between August 15 and September 15. In years of
deficient rainfall, the June, July and August rains seem to fail. The
catchment basin of the Gazelle river may be credited with a mean annual
rainfall of 75 centimetres between May and October, while the mean
annual rainfall on the Arab river cannot be more than 30 centimetres
between June and September. The Sobat river in its upper reaches enjoys
an annual rainfall of about 1.25 metres and of ·75 metres in its lower
reaches. The time of rain is between March and September. The lands
draining into the White Nile north of Tewfikieh have an annual rainfall
of about 20 centimetres between June and September.

The Abyssinian part of the catchment basin of the Blue Nile enjoys a
good rainfall throughout nine months of the year from February to
October, with generally heavy rain between May and September, and very
occasionally in October. The rainfall here may be taken as 1.25 metres
per annum. In the plains of the eastern Sudan traversed by the lower
reaches of the Blue Nile and the Atbara the rainfall is very much
lighter and may be considered as 30 centimetres between July and
September; fairly constant and heavier in the south, and very inconstant
and lighter in the north. The Atbara and its tributaries in their upper
reaches on the northern slopes of Abyssinia, have rain from May to the
end of August and occasionally into September. There are great
fluctuations in the rainfall. The mean annual rainfall may be taken as
75 centimetres.

The desert area between Khartoum and Cairo has occasional winter rains
especially in the parts near the Red sea, but as these rains are nearly
all soaked up by the desert, and very little, here and there, reaches
the Nile, we may neglect them altogether. Railways have to be provided
with culverts and bridges where they cross the terminal reaches of the
khors and wadis which run considerable bodies of water for a few hours
after rain; but the effect on the Nile is practically nothing. Along the
sea-board of the Mediterranean there are a few inches of rain every
winter, sufficient as a rule to raise poor crops of barley.

In the catchment basins of Lakes Victoria and Albert the direction of
the winds may be taken as north-east in winter and south-east in summer.
The maximum monthly temperature may be taken as 35° and the minimum as
12°, with a mean for the year of 21°.

Along the Albert Nile the north wind blows through the winter, and
southerly winds prevail from about the 15th of April to October. The
temperature may be taken as ranging from a monthly maximum of 38° to a
monthly minimum of 16°, with a mean of 27°.

Tables 75 to 81 give the principal meteorological data for many places
in the Nile valley and compare the Bombay rainfall with the Assuân
gauges. The latter show how closely the Assuân gauge in flood follows
the rainfall at Bombay.

At Addis Ababa in the highlands of Abyssinia, the mean monthly
temperature ranges between 19° and 15°, with a mean of 17°. The winds
are south-east and east through the year. In 1902 the rainfall was 980
millimetres, and in 1903 it was 1340 millimetres. (Table 75).

At Wad Medani in the Grezireh south of Khartoum, the mean monthly
temperature ranges between 35° and 24°, with a mean of 30°. The winds
from October to April are from the north and from May to September from
the south. In 1902 there were 350 millimetres of rain and in 1903 there
were 310. (Table 76).

At Khartoum the mean monthly temperature ranges between 34° and 19°,
with a mean of 28°. The winds from October to April are from the north
and from May to September from the south. In 1902 there were 120
millimetres of rain and in 1903 there were 70. (Table 77).

For Alexandria, Cairo and Assuân, representing the Nile valley in Egypt,
I have prepared the following table:--

  =========+====================+====================+====================
           |     ALEXANDRIA     |       CAIRO        |      ASSUAN
           +--------------+-----+--------------+-----+--------------+-----
    MONTH  |  THERMOMETER |Rain-|  THERMOMETER |Rain-|  THERMOMETER |Rain-
           |  Centigrade. |fall.|  Centigrade. |fall.|  Centigrade. |fall.
           +----+----+----+     +----+----+----+     +----+----+----+
           |Max.|Min.|Mean|     |Max.|Min.|Mean|     |Max.|Min.|Mean|
  ---------+----+----+----+-----+----+----+----+-----+----+----+----+-----
           |    |    |    |MILL.|    |    |    |MILL.|    |    |    |MILL.
  January  |25·0| 5·4|24·1|  54 |26·6|-0·7|12·4|   6 |32·5| 4·0|14·8|  ..
  February |29·7| 6·2|14·8|  22 |35·3| 1·2|14·2|   3 |37·0| 5·0|22·0|  ..
  March    |37·0| 5·5|16·1|  17 |41·2| 3·2|16·9|   5 |42·0| 8·0|24·3|  ..
  April    |38·9|11·0|18·5|   2 |42·6| 5·7|20·9|   2 |46·6|11·0|27·3|  ..
  May      |38·9|13·3|21·3|  13 |44·2| 9·0|24·4|   2 |46·0|17·0|29·6|  ..
  June     |39·4|13·8|24·0|  .. |45·2|13·7|27·3|  .. |47·0|20·0|34·2|  ..
  July     |37·0|20·5|26·1|  .. |44·3|17·4|28·5|  .. |46·0|23·0|33·6|  ..
  August   |35·0|20·3|26·6|  .. |41·6|16·5|27·7|  .. |46·0|21·0|35·1|  ..
  September|40·0|18·7|25·6|  .. |40·6|14·0|25·3|  .. |47·0|17·0|31·0|  ..
  October  |37·8|15·0|23·7|   9 |42·1|12·1|23·2|   1 |42·0|18·0|28·7|  ..
  November |32·2|10·8|20·0|  38 |33·6| 3·5|18·1|   6 |40·0|11·0|23·1|  ..
  December |28·9| 6·8|16·0|  80 |29·4| 1·3|14·4|   6 |34·0| 6·0|19·0|  ..
  ---------+----+----+----+-----+----+----+----+-----+----+----+----+-----
  Year     |40·0| 5·5|20·6| 235 |45·2|-0·7|21·1|  31 |47·0| 4·0|26·9|   0
  =========+====+====+====+=====+====+====+====+=====+====+====+====+=====

From the above table we may conclude that at Alexandria, Cairo and
Assuân the absolute maximum thermometers may be taken as 40°, 45° and
47° Centigrade; or 104°, 113°, 116°, Farenheit. The minimum thermometers
as 5·5°, -0·7°, 4·0° Centigrade; or 42°, 31°, 39° Farenheit. The
rainfall at Alexandria, Cairo and Assuân respectively may be taken as
235, 31, and 0 millimetres; or 9, 1¹⁄₄, and 0 inches. The heaviest
rainfall in any individual year at Alexandria and Cairo respectively has
been 308 and 55 millimetres; or 12 and 2 inches. The lightest rainfall
at Alexandria and Cairo respectively in any individual year has been 108
and 7 millimetres; or 4¹⁄₄ and ¹⁄₄ inches. Assuân is practically
rainless. It does rain sometimes at Assuân, but there has been no rain
during the last three years while meteorological observations have been
taken.


7. =The Geology of the Nile Valley.=--South of Gondokoro along the
Victoria and Albert Niles, and at the lakes, the rocks are generally
granites, crystalline schists and quartzites. The hills of Uganda are
covered with red clay and marl on the higher lands, while the valleys
consist of a rich black loam. All the cataracts are granites and
granitic rocks or diorites. The Ruenzori range consists of lofty
volcanoes. The surface of the ground is covered with a fine Kankar
(nodulated limestone) in many places. North of Gondokoro the plains are
formed of sandy deposits mixed with coarse peat in places. The hills of
the Bahr-el-Gazelle and Arab river are all crystalline. Abyssinia is a
volcanic plateau. It is the detritus of this rich volcanic soil swept
down by the Blue Nile and Atbara which constitutes the richness of the
soil of Egypt and of the water of the Nile. Those parts of the eastern
Sudan south of Khartoum and El-Damer and at Kassala, which are the
deltas of the Blue Nile, the Dinder, the Rahad, the Atbara, and the
Gaäsh, are possessed of a soil in every sense similar to that of Egypt
itself. At Khartoum and in the bed of the Blue Nile at Kamlin are
extensive deposits of nodular limestone corresponding to the Kankars of
India.

The main Nile from Khartoum to Assuân flows between low hills and tables
of Nubian sandstone overlying crystalline rocks of gneiss, mica schists,
hornblendic granite and red granite. Where the crystalline rocks come to
the surface we have cataracts; where the Nubian sandstone is at the
surface we have reaches of unbroken water.

From Assuân[4] to near Edfu the Nile flows between hills of Nubian
sandstone, the best known of which is Gebel Silsila. From Edfu to near
Luxor, the Nubian sandstone which overlies the crystalline rocks dips
under the Nile and its place along the Nile Valley is taken by green and
grey clays containing nitrate and phosphate deposits. The former are
inexhaustible and have constituted the manure of this part of the valley
for thousands of years. With these deposits are thick banks of soft
white limestone.

  [4] Condensed from a description of the geology of the Nile Valley in
  Egypt written by Capt. Lyons for the second edition of “Egyptian
  Irrigation”.

From Luxor northwards the clays dip under the Nile and the Nile Valley
is bounded by the superposed white eocene limestone up to Cairo.

The Nubian sandstone is always soft and porous. The limestone is
generally soft, though hard siliceous beds are sometimes met with. North
of Cairo there is no building stone of any value except the siliceous
sandstone of Gebel Ahmar near Cairo and the basalt of Abu Zabel, a
recent outcrop furnishing a black rock of great durability. The area
covered by this rock is small.

Thick deposits of sand and gravel underlie the Nile mud deposits of the
Nile Valley. All along the Nile, but especially south of Luxor, river
deposits of dark sandy mud exist on either side of the Nile Valley
considerably above the level of the deposit of to-day. The best known of
these is the plain of Kom Ombos. The thickness of the layer of Nile mud
in the valley is as much as 18 metres in places, but the average depth
is, I should say, 10 metres.


8. =The discharges of the Nile and its tributaries.=--Reference should
be made to tables 24 and 25 which embody the results of an exhaustive
examination of the observed discharges, the cross sections, the gauges
of the Nile Valley, and the calculated discharge tables made for these
gauges. Many of these tables are founded on only two or three discharges
and some on only one, but they have been prepared with the greatest care
and referred to all the existing gauge observations, and are good
working tables, which can be modified and improved as time places more
information at our disposal. Until then they may be used as about the
best approximations available to-day.

In 1902 the Albert Nile discharged 600 cubic metres per second as
against 520 discharged by the Victoria Nile. In 1903 the Victoria Nile
discharged 730 cubic metres per second and the Albert Nile 800. Leaving
a poor year like 1902 which was much below the average, and taking 1903
which was all round a good average year and only slightly below the
mean, we have the following results:--

The Victoria Nile was at its highest in July with 840 cubic metres per
second, while the Albert Nile at its head was at its highest in December
with 1,060 cubic metres per second. Lake Albert took 5 months to fill
up. At Gondokoro the Albert Nile was at its lowest in April when it
discharged 700 cubic metres per second as against 550 cubic metres in
the previous year. Swollen by timely and good rains south of Gondokoro
the discharge at Gondokoro rose to 2,100 cubic metres per second in
September after the river had scoured out its bed over a metre in depth.
The mean discharge for the year at Gondokoro was 1,200 cubic metres per
second.

The Gazelle river gave no discharge in the first half of the year and
about 30 cubic metres per second in the latter half. Its mean discharge
was 10 cubic metres per second for the year.

The Albert Nile at its tail above the Sobat junction gave as a minimum
350 cubic metres per second in March, which discharge rose to 430 cubic
metres per second in September, but could not rise higher as the Saubat
river was then in flood and the White Nile could not carry off much more
than the discharge of the Sobat without putting the northern part of the
Sudd region under 2 metres of water. This held back water helped later
to maintain the discharge of the White Nile in January and February.

The Sobat river gave as a minimum a discharge of 40 cubic metres per
second in April, and then rose to a maximum in November of 1,080 cubic
metres per second.

At its tail, the Albert Nile gave a mean discharge for the year of 390
cubic metres per second and the Sobat of 550.

The White Nile at its head was at its lowest in April with 400 cubic
metres per second and at its highest in December with 1,460 cubic metres
per second, with a mean discharge of 940 cubic metres per second. At its
tail near Khartoum the White Nile was at its lowest in May with 420
cubic metres per second and at its highest in October with about 1,700
cubic metres per second. As this latter figure was about 400 cubic
metres per second more than it was receiving at its head, the additional
water represented Blue Nile water which had run up the valley of the
White Nile, been stored there while the Blue Nile was high and then been
discharged into the Main Nile when the Blue Nile had fallen. The mean
discharge at the tail of the White Nile was 830 cubic metres per second.
This figure was much below that at the head and was due to the fact that
in July, August and September the Blue Nile water was flowing up the
White Nile.

The Blue Nile was at its lowest in April when it was discharging 120
cubic metres per second. During its maximum in August and September it
was discharging 8,200 cubic metres per second. Of the discharge of the
Blue Nile in July, August and September, a considerable part flowed up
the White Nile which here has a slope of ¹⁄₁₀₀₀₀₀ and a bed from 3,000
to 1,500 metres wide. It is for these reasons that the Blue Nile water
does not hurry on to Assuân in its full strength. The mean discharge of
the Blue Nile for the year was 2,350 cubic metres per second. Gauges and
discharge tables at Kamlin on the Blue Nile, and north of Omdurman on
the Main Nile, would be very much better than the Khartoum or Duem
gauges of to-day which are both in back waters.

The Atbara river was dry from January to May, in June the discharge was
200 cubic metres per second, rising to 2,300 cubic metres per second in
August. In October, November and December it was dry. The mean discharge
for the year was 380 cubic metres per second. When the Atbara river
rises in flood it cannot flow down the Nile to Egypt in its strength
until it has filled up the trough of the Nile as far as the 6th
Cataract. Gauges up and down stream of the 6th Cataract and at Shendy
would be interesting when compared with Berber.

The minimum combined discharges of the White Nile, Blue Nile and Atbara
river were 540 cubic metres per second in April. The maximum combined
discharges of 10,900 cubic metres per second were in August. The mean
combined discharges for the year were 3,560 cubic metres per second.

The minimum discharge of the main Nile above Assuân was 440 cubic metres
per second in May and the maximum of 8,600 cubic metres per second was
in September. The mean discharge for the year was 2,650 cubic metres per
second.

Table 25 gives the actual daily minimum and maximum discharges during
1902 and 1903 for each stream, with their dates. For the Blue Nile in
1903 they were 100 and 9,600 cubic metres per second; for the White Nile
380 and 1,470; for the Atbara 0 and 3,100; and for the Nile above Assuân
420 and 9,000 cubic metres per second.

Table 26 compares the discharges for a maximum year like 1878, a minimum
year like 1877, and a mean year, at Khartoum, Assuân and Cairo. The
maximum discharges in 1877 were 5,300, 5,900 and 4,400 cubic metres per
second, at Khartoum, Assuân and Cairo. In 1878 they were 12,500, 12,100
and 10,300 cubic metres per second respectively, while for a mean year
they are 8,500, 9,200 and 7,200 cubic metres per second.

The modulus of the river at Assuân is 3,040 cubic metres per second, and
at Cairo 2,640. After the very high flood of 1878, the lowest discharge
in May 1879 at Assuân was 1,500 cubic metres per second.

The behaviour of the Nile after passing Assuân and entering Egypt may be
described as follows:--of the mean discharge of 3,040 cubic metres per
second which passes Assuân 400 cubic metres per second are utilised in
Upper Egypt in the irrigation of 2,320,000 acres and 2,640 cubic metres
per second pass Cairo. Of these again 540 cubic metres per second are
utilised in the irrigation of 3,430,000 acres in Lower Egypt, and only
2,100 cubic metres per second reach the Mediterranean sea.




CHAPTER II.

The tributaries of the Nile.


9. =Lake Victoria Nyanza.=--Lake Victoria, the true source of the Nile,
lies on the Equator, and fed by abundant rains and numerous streams,
discharges its surplus waters over the Ripon Falls, and gives birth to
the Victoria Nile. Its most important feeder, the Kagera, whose
southernmost tributary rises in the Kangosi hills 2000 metres above sea
level in south latitude 4°, has a length of some 600 kilometres. The
direct line across the lake from the mouth of the Kagera to the Ripon
Falls is 220 kilometres, so that in academical language the length of
the Nile at the Ripon Falls is already 820 kilometres. Lake Victoria
lies 1129 metres above sea level, and has an area of 60,000 square
kilometres; though until the parallels of longitudes are definitely
settled, the lake may be credited with an area of between 60,000 and
65,000 square kilometres, constituting it the largest fresh water lake
in the old world. Its waters are beautifully clear and perfectly sweet.
The depth of the lake is not great and it is covered with many islands.
The greatest depth found by Commander Whitehouse in the northern half of
the lake has been 73 metres, while the bays are shallow. The northern,
southern and eastern shores of the lake, as described by Sir William
Garstin, are generally clear, while the western shore, especially at the
mouth of the Kagera, is flat, marshy and covered with papyrus. The
country surrounding the lake is undulating or hilly and rises to a
height of 700 metres above the lake at the south-east corner. The rocks
are generally granites, chrystalline schists and quartzites, etc. The
hills are covered with red clay and marl on the higher lands, while the
valleys consist of a rich black loam.

The catchment basin of the lake is 244,000 square kilometres of which
60,000 are water. Most of the important streams feeding the lake
traverse extensive marshes and swamps and must lose a great part of
their waters by evaporation. According to Capt Lyons (Appendix III of
Sir William Garstin’s report), the climate of the lake basin is
typically that which is known as equatorial; two rainy seasons and two
dry seasons make up the year, the rains coinciding more or less with the
equinoxes and the dry seasons with the solstices, except that the second
minor rains are delayed about 1 to 2 months after the autumn equinox. As
Capt. Lyons hopes soon to publish a monograph on the meteorology of the
Nile valley, I shall say little about the details of rainfall of the
different catchment basins, contenting myself with broad principles and
main features. March, April and May form the greater rainy season, and
October, November and December the lesser. The rainfall of the former
season may be considered twice as heavy as that of the latter, but it is
the latter which practically decides the height of the lake in the
following year. This, according to Capt. Lyons, is due to the fact that
in the summer months, when the rainbelt lies to the north of the lake,
the dry south winds must blow across the lake basin even though the
diurnal reversal of winds on the lake is not mastered by them. These dry
winds greatly increase the evaporation, and there is a marked diminution
of the water between July and November, which must be primarily due to
the increased evaporation.

[Illustration: PLATE III.

RIPON FALLS

PLAN AND SECTION

Scale 1 : 6.000

Lith. Sur. Dep. Cairo.

Victoria Nile upstream of Ripon Falls]

The rainfall in the catchment basin may be taken as 1250 millimetres per
annum on the average. As the evaporation off the lake is probably the
same, the area of the lake may be left out of the catchment altogether.
The balance of the catchment basin amounts to 184,000 square kilometres,
on which there is a mean annual rainfall of 230 cubic kilometres. The
mean discharge of the Victoria Nile over the Ripon Falls appears to the
approximately 580 cubic metres per second or 18 cubic kilometres per
annum. This represents about ¹⁄₁₂ the mean rainfall. The greatest
discharge of the lake seems to be about 850 cubic metres per second and
the lowest 450. As the lake has risen in a single year 80 centimetres,
which represents an increase of water of 48 cubic kilometres, and has
fallen 60 centimetres which represents a decrease of water of 36 cubic
kilometres, it will be seen that the discharges from the lake are
factors of less importance in determining the level of the lake than the
heavier rainfall and diminished evaporation in a year of good rain, and
the lighter rainfall and increased evaporation in a year of poor rain.
The great function of Lake Victoria in the economy of the Nile supply is
the insuring of a nearly constant discharge of water into the Victoria
Nile, and providing much of the evaporation which comes down in the
catchment basin itself in the shape of rain.

The principal feeders of Lake Victoria are the following streams:--

  on the north (1) Lukos or Yala,
               (2) the Nzoia 250 kilometres long,
               (3) the Sio.
  on the east  (1) the Nyando,
               (2) the Inyayo,
               (3) the Gori,
               (4) the Mara Dabash,
               (5) the Rawana.
  on the south (1) the Symiya,
               (2) the Moame.
  on the west  (1) the Lohungati,
               (2) the Kagera, with its branches the Nyavarongo, the
                   Akanyaru and the Ruvuvu, with a maximum length of 600
                   kilometres and a discharge varying between 140 and
                   some 600 cubic metres per second.
               (3) the Ruizi with a length of 280 kilometres traversing
                   much marshy ground in its course.
           and (4) the Katonga 250 kilometres long.

The northern and western feeders are generally perennial streams, while
many of the southern and eastern are torrents.


10. =The Victoria Nile.=--From the Ripon Falls to Lake Albert, the
Victoria Nile has a length of 400 kilometres. The first 64 kilometres
are down a steep slope, in a stream varying from 300 to 500 metres in
width. Any project for a regulator at the Ripon Falls should contemplate
development of electricity for working a railway along these 64
kilometres. The next 237 kilometres are through a flat marshy land,
partly lake, partly swamps, but with the water never more than 4 to 6
metres deep. In this reach the Nile is navigable. This many-armed swamp
is known as Lake Choga, whose western end is traversed for some 80
kilometres by the Nile with a perceptible current. These large sheets of
papyrus and water, which cover an area of over 2000 square kilometres,
must cause as much loss by evaporation as they receive by direct
rainfall. The Victoria Nile leaves the lake in a broad stream some 900
metres wide, past Mruli station, on to Fowera. In the longitudinal
section on Plate II, I have considered Fowera as 1060 metres above sea
level, and the slope upstream of it as ¹⁄₂₀₀₀₀. From Fowera to the foot
of the Murchison Falls, the Nile falls 377 metres on a length of 68
kilometres, and then in the next 30 kilometres reaches Lake Albert.
Considerable quantities of floating pistea weeds pass down the Victoria
Nile from Lake Choga. They are well churned up between Fowera and the
Murchison Falls, but finally enter Lake Albert. It would be easy to
develop electricity to work a railway along these 68 kilometres.

[Illustration: PLATE IV.

CROSS SECTIONS of the NILE & its TRIBUTARIES

_Horizontal Scale 1 : 2.000_

_Vertical Scale 1 : 600_

Lith. Sur. Dep. Cairo.

No. 1. _Victoria Nile upstream of Ripon falls_

No. 2. _Kagera River within 10 km. of mouth_

No. 3. _Semliki River about 50 km. upstream of Albert Lake_

No. 4. _Albert Nile at Wadelai._

No. 5. _Asua River about 2 km. above junction with Nile._

No. 6. _Albert Nile at Gondokoro._

No. 7. _Albert Nile at Mongalla_

No. 8. _Albert Nile above Lake Nô_

No. 9. _Bahr el Ghazal 51 km. from mouth_

No. 10. _Bahr el Zeraf 20 km. from mouth_

No. 11. _Albert Nile 4 km. above junction with Sobat_

No. 12. _Sobat River at Doleib Hills_

No. 13. _White Nile 14 km. below Taufikia_]

The principal tributaries of the Victoria Nile are the following:--

On the right bank, the Gogonia, the marshy Kwania and Lenga, and the
Duki. And on the left bank; the lake-like Sensiwa; the Kafu with its
numerous feeders, large catchment basin but generally insignificant
discharge; and the Titi. The Uganda rivers are more like sponges than
rivers, and in all probability the tail of the Victoria Nile has a
discharge only slightly in excess of that at the head.


11. =The Semliki River.=--The Semliki river has its sources in Lake
Edward just south of the Equator and flows into the southern end of Lake
Albert, just as the Victoria Nile flows into the northern end. Lake
Edward with the addition of Lake Dueru has an area of some 2500 square
kilometres and lies about 965 metres above sea level. Its waters as
described by Sir William Garstin, are green in colour and brackish. The
Semliki river discharges the surplus waters of the lake, and may be
considered as having a discharge of 100 cubic metres per second as a
minimum and 400 cubic metres per second as a maximum. In some 120
kilometres of its length this river traverses the eastern end of the
Congo forest, and the day may not be far distant when this timber will
be floated down the Semliki, towed across Lake Albert and sent down the
Albert Nile to Gondokoro and Khartoum. The fall of the Semliki,
according to accepted levels is 285 metres in 260 kilometres. The
feeders of Lake Edward are the following:--

  On the west, none.

  On the south, the Rutshuru and Ruendu.

  On the east, the Msalala, the Wampuna, the Chambura, and the Mpanga
  which has its sources on the slopes of Ruenzori.

  On the north, numerous glacier-fed torrents from the slopes of
  Ruenzori, the Nyamgasha and the Dibirra. The dry season discharges of
  all these rivers are small. The largest is under 10 cubic metres per
  second. The flood discharges are considerable.


12. =Lake Albert Nyanza.=--Lake Albert has an area of 4500 square
kilometres and lies about 680 metres above sea level. We have left the
high lands of Uganda and are in the stifling heat of tropical Africa.
There are considerable deposits of salt along the east shore of Lake
Albert, as there are also around Lake Edward. According to Sir William
Garstin, the waters of Lake Albert are brackish near the shores, but
perfectly sweet and clear in the middle of the lake. It is due to the
waters of Lake Victoria that those of Lake Albert are sweet. The
catchment basin of the Albert Nile at its head where it leaves Lake
Albert is about 379,000 square kilometres of which 244,000 square
kilometres discharge into Lake Victoria. The rainfall over the
additional 135,000 square kilometres may be considered as 1250
millimetres per annum, with seasons similar to those on Lake Victoria.
The evaporation from Lake Albert must be greater than that from Lake
Victoria, but if we exclude the joint areas of Lakes Victoria, Albert,
Edward and Choga, and taking them as 70,000 square kilometres, consider
that their rainfall is equalized by their evaporation, there remains
from the 379,000 square kilometres of catchment basin about 309,000
square kilometres. An annual rainfall of 1250 millimetres means for
309,000 square kilometres a total rainfall of 380 cubic kilometres. The
discharges of Lake Albert may be taken as varying from 500 cubic metres
per second to 1100, with a mean of 800 cubic metres per second. This
latter figure represents in one year 26 cubic kilometres or ¹⁄₁₅th the
annual rainfall. We may compare with this the mean discharge of Lake
Victoria of about 580 cubic metres per second and ¹⁄₁₂th of the annual
rainfall of its catchment basin excluding the lake area.

A reference to Plate V will show how great is the regulating effect of
Lake Albert on the Nile. Owing to the fact that an increase in the
discharge of the Victoria Nile cannot pass down the Albert Nile before
the whole area of Lake Albert has risen, the floods of the Victoria Nile
are delayed nearly 5 months in their passage down the Albert Nile; a
rise of 1 metre on Lake Albert meaning an increased cube of
4,500,000,000 cubic metres. If this takes place in one year, it
represents an increased discharge of 150 cubic metres per second
irrespective of what passes down the channel of Lake Albert.

If it were considered necessary to insure 1200 cubic metres per second
as the discharge of the Albert Nile from the 15th January to the 15th
May, it would mean adding 400 cubic metres per second to the mean
discharge for 4 months, and deducting 200 cubic metres per second from
the mean discharge for the remaining 8 months. By storing the surplus
waters of good years by means of a weir capable of holding up 3 or 4
metres of water at the outlet of the lake, it would be possible to
insure this discharge every year during the four months which decide the
summer contingent of the White Nile to the Nile in Egypt during the
months of April, May, June and July.

[Illustration: PLATE V.

GAUGE & DISCHARGE DIAGRAM of LAKES VICTORIA & ALBERT

_Luba (subsequently Jinja) gauge, near the Ripon Falls, represents Lake
Victoria._

_Wadelai gauge (60 km. below Lake Albert) represents Lake Albert._

Lith. Sur. Dep. Cairo.]

The shores of Lake Albert are generally steep and barren, though in
places they are shelving and covered with papyrus, notably at the inlets
of the Semliki river and the Victoria Nile. The Lake is fairly deep and
admirably suited for a reservoir. At the outlet of the lake enormous
quantities of pistea weeds, especially in high floods, enter the Albert
Nile. The passage of these weeds through the future regulator of Lake
Albert will be an exceedingly interesting engineering problem.

The principal feeders of the lake are:--

  On the north, the Victoria Nile.

  On the east, the Waiga, the Wakki, the Hoima, the Wahamba, the Horo,
  the Ngusi and Msisi, discharging between them under 20 cubic metres
  per second in the dry season, though good streams in flood.

  On the south, the Semliki; and no streams worth mentioning on the
  west.


13. =The Albert Nile.=--The Albert Nile, or the Bahr-el-Gebel, has a
length of 1280 kilometres from Lake Albert to the mouth of the Sobat
river. For 218 kilometres, past Wadelai to Dufile, it has a broad stream
with a sluggish current as a rule, and covered with islands and papyrus
marshes. This reach of the Nile is navigable. The fall here must be very
little, and it may be considered as 8 metres. In high floods enormous
quantities of pistea weeds float down this reach of the Nile. Papyrus
and ambatch are very common along the shores and on the islands.

At Dufile begin the Fola rapids followed by numerous cataracts up to
Fort Berkeley. In this reach of 155 kilometres the river falls 223
metres. Sir William Garstin states that some of the falls have a width
of only 12 metres. The depth must be extraordinary, while the velocity
is terrific. The green water of the upper reaches is purified in its
passage through these cataracts. The rock is granite. If the regulator
for Lake Albert were constructed near Dufile, it should contemplate
development of electricity for working a railway along these 155
kilometres.

South of Dufile the principal tributaries of the Albert Nile are on the
right bank viz: the Achua and Umi. In the dry season they are dry, but
after rains they may add some 50 cubic metres per second to the river.
Between Dufile and Fort Berkeley many rivers flow into the Albert Nile.
The Asua, the Atappi, the Umi, the Karpetu, the Kweh and many others
from the right bank bring down water in flood well laden with sand. In
the dry season all but the Asua are dry. The left bank tributaries are
numerous but insignificant. The volume discharged by these streams in
the rainy season is very considerable, as will be seen if the discharges
at Gondokoro north of Fort Berkeley are compared with those at Wadelai.
They are between them capable of increasing the discharge of the Albert
Nile for short intervals of time by 1500 cubic metres per second. All
these streams are torrential. They rise and fall quickly.

From Fort Berkeley to Khartoum, the Albert and White Niles are
navigable.

From Fort Berkeley to Bor past Gondokoro on a length of 206 kilometres
the Albert Nile falls some 18 metres and has a good velocity and slope,
and though the river is divided into two and more channels, it is within
its banks and may be considered an ordinary river. The maximum discharge
is about 2600 cubic metres per second and the minimum 550. In high
floods the river scours out its bed and sides very considerably. The
real flat lands begin at Gondokoro a little to the north of Fort
Berkeley. The soil is light and sandy and capable of offering little
resistance to the stream. Between Gondokoro and Bor the Albert Nile can
lose some 30 per cent of its discharge when the river is high and
capable of overflowing most of the islands and a great part of the
valley. The main channel has a width of about 230 metres and depth of 3
or 4 metres when the discharge is below 600 cubic metres per second and
well within banks. The main tributaries of the Albert Nile in this reach
are on the east bank, the Kit, second only to the Asua, and the
Lokadero; and on the west bank a number of unimportant torrents which
however help to swell the river in flood.

From Bor to Ghaba Shambe on a length of 196 kilometres, the main stream
of the Albert Nile flows between banks lower than those further south
and more heavily inundated in flood, with a width of some 60 metres and
depth of water of 5 metres. According to Sir William Garstin, the grass
swamps end half way down this reach and the papyrus swamps begin. About
10 kilometres to the east of the main stream is another branch known as
the Atem river fed by artificially maintained and natural spills from
the main stream itself. These spills are kept open by the Dinkas living
along the Atem river. They were noted by Werne in 1842. The Atem river
at its tail apparently divides into two branches, of which one feeds the
Zeraf river and the other returns to the Nile at Ghaba Shambe.

Capt. Lyons has pointed out to me that all this course of the river is
extraordinarily like the course of the Mississippi south of Vicksburg,
with its severe curves and oxrings which correspond to the mayahs of the
Albert Nile. Such mayahs or lagoons can be seen in the last 20
kilometres of the Rosetta branch of the Nile. Placed as they are between
Bor and Ghaba Shambe, they mean that while south of Bor, the Albert Nile
has more or less formed its delta; north of Bor, the delta is in a more
embryonic stage, with probably the Atem river the more ancient of the
two streams. North of Ghaba Shambe, the Zeraf river leaves the Albert
Nile, and fed by the Atem Nile, takes off its water eastwards through
marsh and swamp to again tail into the Albert Nile below Lake No. About
30 kilometres further north is the cut made by Sir Samuel Baker to
enable him to enter the Albert Nile from the Zeraf river.

The real Sudd region lies between Ghaba Shambe and Lake No, on a length
of 380 kilometres. Between Fort Berkeley and Gondokoro, the flood as
well as the summer supplies are within banks. Between Gondokoro and Bor,
the summer supply is well within banks, but the floods overflow the
valley. Between Bor and Ghaba Shambe the summer supply is just within
banks, but the floods overflow freely. Between Ghaba Shambe and Lake No
the summer supply overflows the banks, and hence there result the
periodical barrings or sudds of the Nile by the floating vegetation so
common in this region. While the summer supply is within banks it can
insure a clear waterway; but when not only the floods but the summer
supplies ordinarily overflow the banks, the stream must be aided
artificially if it is to keep its waterway clear.

The ordinary width of the river south of Hillet-el-Nuer is between 50
and 60 metres, but in the reach of the old sudd blocks numbers 16 to 19
it diminishes in places to 25 metres, and in the reach blocked by sudd
block number 15 increases to 200. North of Hillet-el-Nuer, the width
varies from 60 to 150 metres, but the mean width may be taken as from 75
to 80 metres. The velocity is about 75 centimetres per second, which is
a good velocity for clear water; and Sir William Garstin remarks at one
place that since the sudds were cleared the channel of the Albert Nile
seems to be deepening and widening itself, and he states in another
place that the extent of overflow over the mayahs or side depressions is
decreasing.

With proper training works and dredging it should be possible to reduce
the length of the main channel of the Albert Nile between Gondokoro and
Bor from 175 kilometres to 160; between Bor and Ghaba Shambe from 206
kilometres to 145; and between Ghaba Shambe and Lake No from 380
kilometres to 305. Or the length of channel from Gondokoro to Lake No
might be reduced from 761 kilometres to 610. Some of the curves are
nearly complete circles, needing but little work to cut off extensive
lengths.

Between Ghaba Shambe and Lake No there were 19 sudd blocks of which all
but one were removed by Major Peake, R. A., and Lieut. Drury, R. N., in
1900 and 1901. Their positions are indicated on Plate VI. South of
Hillet-el-Nuer is sudd block No. 15, the only one remaining to be
removed. Owing to this block, the Albert Nile leaves its true channel,
which is from 5 to 6 metres deep, and, on a length of 43 kilometres,
follows a series of mayahs, pools and marshes with a depth of from 1¹⁄₄
to 2 metres. The original channel was closed by a boat laden with ivory
sinking in the true channel during the Dervish domination. The boat has
been found, the ivory recovered and the work of sudd clearing commenced,
but the work has not yet been completed.

The maximum discharge of the Albert Nile at Hillet-el-Nuer may be taken
as 450 cubic metres per second, and into Lake No as 320 cubic metres per
second. The water of the river is dark-coloured and contains no
sediment. Very little ambatch is met with north of Ghaba Shambe.

Between Ghaba Shambe and Lake No on the left bank, in the first 120
kilometres, three channels carrying very appreciable quantities of water
flow into the Albert Nile. These are considered to be the tails of the
river Yei. At Hillet-el-Nuer, about 170 kilometres north of Ghaba
Shambe, a branch takes off from the west side of the Albert Nile, known
as Gage’s channel, with 35 metres of clear waterway, 1 metre depth and
0·60 metre per second velocity, discharging 20 cubic metres per second.
This stream flows westwards and is lost in the swamps. On the right
bank, downstream of Ghaba Shambe, are the two heads of the Bahr Zeraf,
one natural and the other artificial made by Sir Samuel Baker. About 90
kilometres north of Ghaba Shambe a few spills take water towards the
Zeraf river.

[Illustration: PLATE VI.

THE ALBERT NILE.

FROM GONDOKORO TO THE SOBAT JUNCTION

Scale 1 : 2,000,000

Lith. Sur. Dep. Cairo.

Part of Albert Nile

_South of Sudd No. 15_]

From Lake No to the Sobat mouth, on a length of 134 kilometres is the
tail reach of the Albert Nile. The Albert Nile flows into Lake No in its
south-eastern corner and leaves it on its east side. On the west side
the Gazelle river flows into the lake. Lake No has an area of some 20
square kilometres in times of low supply and 100 square kilometres in
flood. In low supply the depth is between 1·50 and 2·50 metres. In the
reach between Lake No and the Sobat mouth, the river is very fairly
straight; the summer channel is about 170 metres wide and as a rule
about 5 metres deep upstream of the mouth of the Lolle, though in one
place about 8 kilometres from Lake No it becomes only 50 metres wide for
a short distance. Between the tail of the Lolle river and the mouth of
the Sobat river, the summer width widens out to about 400 metres with 3
metres depth of water. However extensive the marshes may be, the high
land forming the limit of the inundation is everywhere in this reach
visible from the main stream. The Gazelle river, which flows into Lake
No, has a discharge varying from 0 to 40 cubic metres per second. The
Lolle river which flows in on the left bank upstream of the Sobat mouth
is probably an arm of the Albert Nile or an overflow of the Gazelle and
has a discharge varying from 0 to 40 cubic metres per second. On the
right bank, the Zeraf river flows into the Albert Nile, with a discharge
varying from 30 to 160 cubic metres per second. The Megahid river flows
in 30 kilometres below the tail of the Zeraf river and adds an
undetermined quota of water.

At its junction with the Sobat river, the Albert Nile discharges from
300 to 450 cubic metres in summer; it does not discharge much more in
flood as the waters of the Sobat river in flood hold up the Albert River
and make it overflow the low lands up to Lake No and beyond for a depth
of 3 metres in high floods. This reach of the Nile is a flood reservoir,
which empties itself ordinarily by the end of winter.


14. =The Gazelle River.=--The Gazelle river, which flows into Lake No,
has a catchment basin of 240,000 square kilometres, with an annual
rainfall of 75 millimetres; and an additional catchment basin of 230
square kilometres with an annual rainfall of 30 millimetres; and yet the
river discharges nothing in summer and about 40 cubic metres per second
in flood. It is the most extraordinary river in the world, often blocked
by sudd and invisible. It has practically no banks in flood or in times
of low supply, while the waterway varies in width from 6 metres to 90
and in depth from 2 metres to 6 metres. It makes its way between
interminable marshes of papyrus and water grasses. The Gazelle river is
a deltaic river in a still more embryonic stage than the Albert Nile
north of Ghaba Shambe. It, however, performs one good function. It keeps
the swamps of the Sudd region full of water, year in and year out; and
without it, the water of the Albert Nile would doubtless be lost by
percolation in the Sudd region and the White Nile be left high and dry
for 3 months every year.

Schweinfurth was the first to ascend and describe this river and its
tributaries. Beginning from the east, its principal tributaries
are:--the Rohl, the Dyow, the Tondy, the Kit, the Dyûr, the Dembo, the
Humr and the Bahr el Arab. With courses of between 450 and 750
kilometres in length, the tributaries fall from 500 to 700 metres in
their upper courses of from 300 to 500 kilometres, and in their
remaining courses they traverse swamps. Certain of the tributaries may
be discharging 10 cubic metres per second in summer and 250 cubic metres
per second in flood, but the main stream of the Gazelle seems never to
add more than 40 cubic metres per second to the Albert Nile. The whole
of the water is evaporated from the weeds, papyrus, watergrasses and
open sheets of water which cover a desolate area of 70,000 square
kilometres. Evaporation and rainfall balance each other. If the
«Singhara» or Indian water nut could be induced to grow in this waste of
waters, some profit might be got out of them.


15. =The Bahr Zeraf.=--The Bahr Zeraf is the right hand branch of the
Albert Nile which leaves the latter river north of Ghaba Shambe and
joins it again midway between Lake No and the Sobat river. It is fed
largely by the escape water of the Atem river brought down in a
traceable channel and in flood by torrents from the hilly region east of
Gondokoro. Beginning with a series of marshes and swamps, it gradually
establishes its right to be called a river and finally after a tortuous
and meandering course of about 270 kilometres tails into the Albert
Nile. In its lower reaches it is about 50 metres wide and from 2 to 4
metres deep in summer and 6 to 8 metres deep in flood. Its discharges
vary from 30 cubic metres per second in summer to 160 cubic metres per
second in flood. In its lower reaches the banks consist of solid earth,
proving that at one time it carried water other than that brought down
by the Albert Nile.


16. =The Sobat River.=--This river drains 156,000 square kilometres
lying between the catchment basins of Lake Rudolf and the Blue Nile. The
rainfall in the mountainous region of Gallaland is plentiful and
especially heavy in autumn, and were it not for the extensive lakes and
marshes in its middle course, it would be a torrent in flood. Regulated
and restrained by the lakes and marshes, this river has an
extraordinarily even rise and fall, as a reference to Table 24 will
certify. It is unfortunate that the Nasser gauge has been read so
interruptedly. The Doleb Hilla gauge is in the back water of the Albert
Nile and not very reliable. The discharges of the last four years have
varied from 40 cubic metres per second in low supply to 1000 cubic
metres in flood, though there have been years when the discharges have
fallen to zero in summer and when the flood must have exceeded 1500
cubic metres per second. April is the month of low supply and November
of maximum flood.

In its last 50 kilometres, the river has a deep, well defined channel
between high banks, which are never topped in the highest floods. The
width of waterway is about 110 metres and the depth 7 metres in summer
and about 10 to 11 metres in flood.

The principal tributaries of the Sobat are the Baro from the north-east
and east, and the Akobo and Pibor from the south-east and south. All the
tributaries meet and form extensive swamps from which the Sobat has its
origin. The village of Nasser is situated on the Sobat near its origin.
A gauge has been erected here.


17. =The Sudd region.=--The Sudd region of the Albert Nile lies north of
Ghaba Shambe and corresponds to that part of the river where not only do
the floods overflow the banks, but the summer supplies can do so in many
places. It is the delta of the river in a very embryonic stage. There
are two main branches to the river, the Albert Nile proper and the
Zeraf, which have both been already described. Both these rivers are
liable to be blocked by sudd or blocks of living vegetation. These
blocks are sometimes as much as 5 metres thick and capable of turning
nearly the whole supply of the river out of its course. They are formed
of papyrus, weeds and watergrasses, which grow on the half sandy half
peaty banks of the lagoons and marshes traversed by the river, and
which, under the double action of a rising flood and strong winds, are
torn up and driven into the channels wherever they are confined in
width, and there jammed into solid masses of floating weeds, filling the
whole width of the river, very nearly the whole depth, and sometimes
over a kilometre in length. In addition to the local weeds and grasses,
there are always at hand in high floods dense masses of pistea weeds
which have come from the upper waters of the Albert Nile south of
Dufile. While the sudd floats it is not so bad as when it sinks, as it
has done at block No. 15 north of Gaba Shambe, where the Nile has left
its course for 37 kilometres owing to sunken sudd. When the sudd sinks,
its becomes putrid and especially loathsome.

The Sudd region is unmistakably, as Lombardini pointed out years ago, an
old lake which has silted up and become full of peat and sand deposits.
At one time the lake must have had an extreme length of 400 kilometres
and width of 400 kilometres and been a larger sheet of water than lake
Victoria. The Sobat river flowed into it, and the Blue Nile may have
flowed backwards up the bed of the present White Nile for tens of
thousands of years. The north-east corner has been better filled with
deposit than any other part.

The dense masses of papyrus and water-grasses which shut out the horizon
in every direction intimidated the expedition sent up the Nile by Nero,
and it returned northwards without having accomplished anything. From
Nero’s time to that of Mehemet Ali little was known of these regions.
Mehemet Ali made a determined effort to discover what lay beyond these
inhospitable regions, and sent up a well-equipped expedition under
D’Arnaud.

One of the earliest descriptions of the Nile between the fifth and tenth
parallels of latitude is by Werne, who accompanied D’Arnaud’s expedition
sent by Mehemet Ali in 1840-1841. The expedition found the channel of
the White Nile and Albert Nile easily navigable between December and
March. The Albert Nile between 7° and 9° N. lat. had apparently a mean
width of 120 metres, depth of 5 metres, and velocity of about 60
centimetres per second, giving a discharge of some 400 cubic metres per
second. In this first description of the river the fact that strikes one
most forcibly is the omission of the Bahr Zeraf. Neither the inlet nor
the outlet are mentioned, though the Sobat, the Gazelle, and numerous
insignificant streams are minutely recorded. Practically the whole of
the water was confined to one stream, and that a good one. The water
level in winter was found to be some 50 centimetres below the general
level of the berm, and about 60 centimetres above this level in flood.
The swamps contained offensive and fetid water, which mixed with the
waters of the rising flood and helped to pollute the stream on the first
rise of the river. Between the river and the swamps in its southern
reaches were numerous cuts and openings, some natural and some
artificial, made by the aborigines for fishing purposes. While
traversing the swamps, the waters of the river in flood lost their silt
and became quite clear. On page 100 of Vol. II of Werne’s work there is
this significant sentence: “The report that the natives below (i.e. in
latitude 5° to 7°) had blocked the river to cut off our retreat, turned
out to be unfounded.” From the above it will be noticed that the
aborigines in 1840-1841 spoke of their ability to block the course of
the river, while the training works in the side channels and spills for
fishing purposes were described as solid works regulated by rows of
strong stakes driven into the ground.

Between 1841 and 1863 the expeditions up the Nile considerably
increased, while the aborigines were being brutally treated by the slave
traders. What could be more natural than that, as a measure of
protection, the aborigines should have widened and deepened the side
channels and spills which took off from the river between latitudes
5¹⁄₂° and 7¹⁄₂°, so that they might escape from the traders.
Subsequently, when the main river was patrolled by Government boats, the
slave-traders themselves used these side channels for prosecuting their
traffic. All the channels and spills tailed into the Bahr Zeraf, which
now began to form an appreciable stream, and which was navigated over
the lower part of its course by Petherick between 1853 and 1862. The
Bahr Zeraf was however always described as sudded, while the Albert Nile
was open to navigation. This action of dissipating the waters of the
river went on increasing till 1863, when there occurred a very high
flood indeed; the floating weeds brought down from the south were
excessive, the waters escaped everywhere from the main stream, while the
floating masses of creepers were confined by the grasses and papyrus to
the main channel, and sudded it downstream of Lake No.

On ascending the White Nile and Albert Nile in January 1863, Sir Samuel
Baker found the passage clear to the south. On returning in April 1865,
he found the sudd of the flood of 1863 still in the Albert Nile
downstream of Lake No. The sudd was 1000 metres long and had a passage 3
metres wide cut through the middle of it, down which the river ran like
a mill race.

In February 1869, Dr. Schweinfurth and his party, on their way to the
Gazelle, took six days to get through this sudd, though the main
obstruction was now only 200 metres long. In July 1872, Dr. Schweinfurth
on his way back found the sudd to the downstream of Lake No as before,
and described the opening through it as “a narrow stream of water which
rushed along as a wild brook. The depth of the fairway varied from 2 to
3 metres, and the boat nowhere touched the bottom.”

In February 1870 Sir Samuel Baker found the sudd in the Albert Nile
impossible for his expedition of heavily laden boats and steamers. He
found the Zeraf sudded in its southern 100 kilometres, and tried to cut
his way through but failed. And yet the slave traders had means of
getting slave boats down the Bahr Zeraf (“Ismailia” pages 61, 62 and
29). Baker returned in January 1871 to the Zeriba Kutchuk Ali on the
Bahr Zeraf and had before him the 100 kilometres of sudded channel. With
the aid of 1200 men he completed the work by March 13. The final
operation was a canal through stiff clay 600 metres long (known to-day
as Baker’s cut). The fall from the Albert Nile into the Bahr Zeraf was
so great that, in order to get the boats and steamers across the final
distance, Baker made a dam 120 metres long across the Zeraf by means of
a double row of piles, sand bags and fascines of the tall grasses. He
thus secured the necessary depth of water, and the flotilla sailed into
the Albert Nile. On his way back in June 1873, he thus describes the
appearance of the head of the Ziraf river where he had made the cut in
March 1871:--

“On arrival at the Bahr Zeraf cut, we found that the canals which we had
formerly cut were much improved by the force of the stream. Although
these passages were narrow, they had become deep and we progressed with
comparatively little trouble.” The rest of the journey down the Bahr
Zeraf was easily performed.

In January 1874, when the river was low, the sudd in the Albert Nile was
removed by Ismail Pacha Ayoub, Governor General of the Soudan.

From 1874 to 1878, while Gordon was Governor General, the Albert Nile
was clear of sudd, but the wide stream of 1840 had dwindled down to a
clear waterway free of weeds on a width of 6 metres over long reaches.
The escape of water down numerous spills had deprived the Albert Nile of
the power of keeping its channel clear and when the heavy flood of 1878
came down, the river was sudded.

In 1880 Gessi was blocked in the Bahr Gazelle. The sudd in this Bahr was
cut by Marno, who also cut the sudd in the Albert Nile in April 1880.

Emin Pasha mentions the fact that the Albert Nile was free of sudd and
navigated from 1880 to 1883. In 1884 he states that no steamers reached
Lado, but he attributed that to the Mahdi’s rebellion.

During the early years of the Mahdi’s and Khalifa’s rule there was no
sudd. In the Khalifa’s time a boat laden with ivory sank in the stream
where sudd block No. 15 is, south of Hillet-el-Nuer, and caused the
block to form.

In 1898 Lord Kitchener found the Albert Nile sudded south of Lake No,
and in March 1899 Sparkes bey, of the Egyptian Army, steamed up the Bahr
Zeraf to within 30 kilometres of its head.

At the same time Sir William Garstin thought the Bahr Zeraf a stronger
stream than the Albert Nile.

Descending the Albert Nile from Uganda, Colonel Martyr found the Albert
Nile sudded 30 kilometres north of Ghaba Shambe.

In 1900 and 1901 Major Peake, C. M. G., R. A., and Lieut. Drury, R. N.,
removed sudd blocks Nos. 1 to 14, and 16 to 19, between Lake No and
Ghaba Shambe. There now remains only block No. 15 south of
Hillet-el-Nuer.

The condition of the channel to-day has been described under the heading
of the Albert Nile. It is a very fair channel except at the diversion
round block No. 15, which Sir William Garstin is very eager to see
removed.


18. =The White Nile.=--The White Nile stretches from the Sobat mouth to
Khartoum and has a length of 838 kilometres and very little fall. It
everywhere bears traces of having been the channel of the Blue Nile when
in ancient times the Gebel-Royan hill had not been cut through by the
Nile, and the Blue Nile itself flowed south into the great lake which is
to-day the sudd region of the Albert Nile. If the Blue Nile discharged,
as it does to-day, about 2500 cubic metres per second throughout the
year, the Sobat 600 cubic metres, the Albert Nile 1000, the Gazelle
tributaries 700, and the rainfall on the lake itself was 1 metre per
annum, while the evaporation was 2¹⁄₂ metres, (all reasonable figures),
the water entering the lake was 300 cubic kilometres per annum and the
evaporation was the same, provided the lake had an area of 120,000
square kilometres, which is, moreover, reasonable when we examine the
plan. During the whole of this period, the valley of the Nile in Egypt
received its water from the Atbara alone.

The waters of the Sobat river in flood give its name to the White Nile.
At Tewfikieh, near the head of the White Nile, is a gauge. For the first
500 kilometres the river is described by Sir William Garstin as having a
waterway of from 300 to 500 metres in width with numerous islands. The
depth of water in summer is 5 metres and 7 metres in flood. On either
side of the waterway is a low ridge swamped in flood, and beyond that on
either side is a deep depression, deep in the centre and rising to the
ridge on one side and to the high land and forest on the other. Each
depression may be 3 kilometres in width where it is wide and a few
hundred metres where it is narrow, so that the flooded valley may have a
width of 6 kilometres in places. The ridges are about 3 metres wide, and
broken by openings through which the water passes in and out of the side
marshy depressions. The depressions are covered by a dense growth of
reeds and papyrus. When the reeds are burnt one can traverse the marshes
on foot. South of Kaka (200 kilometres north of the Sobat mouth) the
depressions are lower than they are further north, which, to me, goes to
prove that the channel of to-day is formed within the channel of old
days when the Blue Nile was flowing south into the Sudd region. At
Gebelain (250 kilometres north of Kaka) the side depressions contract
and the forests come nearer the river. At the Abu Zeid ford, 50
kilometres further to the north, is a serious obstacle to navigation
when the river is low, in the shape of a very broad sheet of shingle
studded thick with fresh-water oysters. This bar is 6 kilometres long,
as hard as stone, and has in very low summer supplies a depth of water
over it of only 50 centimetres. It is a wonder that a channel has not
been blasted through it. The swamping now visibly decreases and the
width of the river varies from 700 to 900 metres. Some 25 kilometres
north of Abu Zeid the papyrus and sudd grasses disappear, and though
there is flooding there are no swamps. We have now some well cultivated
islands in the river for the negroes have come to an end and the Arabs
inhabit the country. The summer channel may be now considered as 700
metres wide and the flood channel as 1300 metres. The summer depth of
water is 4 metres. At Duem, 220 kilometres south of Khartoum, the width
of the channel widens from 900 to 1000 and further north to 1500 metres,
and finally to 3000 metres. We are in a lake rather than in a river, and
in flood when the waters of the Blue Nile travel 300 kilometres up the
White Nile, and wait for a fall in the Blue Nile to discharge themselves
into the Nile, we are indeed in a pulsating lake and not in a river. It
must have been in September, when the discharge of the Blue Nile had
fallen from some 11,000 to 6,000 cubic metres per second, and the
stored-up waters in the valley of the White Nile were forcing themselves
down to take the place of those cut off from the Blue Nile, that Linant
Pasha took his discharges of the Blue and White Niles and found them
some 6000 and 5000 cubic metres per second respectively. The same remark
may be made about M. Chélu’s discharge of the White Nile at Khartoum of
4000 cubic metres per second in September 1876 and mentioned in his book
“_Le Nil, le Soudan, l’Égypte_,” page 17.

[Illustration: PLATE IX.

CROSS SECTIONS OF THE NILE & ITS TRIBUTARIES

_Horizontal Scale 1 : 2.000_

_Vertical Scale 1 : 500_

Lith. Sur. Dep. Cairo.

No. 14. _White Nile at Duem._

No. 15. _Blue Nile at Lake Tsana_

No. 16. _Blue Nile at the Bridge 30 km. from Lake Tsana_

No. 17. _Blue Nile at Wad Medani_

No. 18. _Blue Nile at Khartoum_]

In 1903 the minimum discharge of the White Nile at its head was 380
cubic metres per second in April and the maximum discharge was 1470
cubic metres per second in December. Table 24 gives the behaviour of the
river. The minimum discharge of the White Nile at Khartoum may be taken
as 300 cubic metres per second. The preceding paragraph will explain how
difficult it will be to know its maximum discharge until a gauge and
discharge table are established for the Blue Nile 100 kilometres above
Khartoum well above back water, and a gauge and discharge table in the
Main Nile north of Omdurman. The difference between these two discharges
will be the true discharge of the White Nile which, with its slope of
¹⁄₁₀₀₀₀₀ in flood, is not a river but a flood reservoir. The discharges
taken at Duem on the White Nile and at Khartoum on the Blue Nile in 1902
and 1903 are interesting, but of little value for anything except the
very date on which they were taken. They were all in backwaters.


19. =The Blue Nile.=--Compared to any river we have yet described, the
Blue Nile is a true mountain stream. Draining the southern and more
rainy half of Abyssinia, it is the principal source of the Nile in
flood. Whatever waters it receives, it carries to the Nile and it is the
true parent of the land of Egypt, for the deposit from its muddy waters
is that Nile mud which has made Egypt. The Atbara carries waters which
are probably more muddy than those of the Blue Nile, but compared to the
Blue Nile the Atbara is a small river, and its quota is insignificant by
the side of that of the larger stream. The principal tributary of the
Blue Nile, the Abai, rises at a height of about 2,700 metres above sea
level and after a course of 110 kilometres falls into Lake Tsana. Lake
Tsana lies at a level of about 1,760 metres above sea level, and has an
area of about 3,000 square kilometres and catchment basin of about
14,000 square kilometres irrespective of the lake area. On the 31st of
January 1903, after a very poor rainfall, Mr. C. Dupuis found the
discharge 42 cubic metres per second. Calculating from his cross
section, it seems that the maximum discharge may be 200 cubic metres per
second. As at Lake Victoria, possibly not more than ¹⁄₁₂th the rainfall
finds its way into the lake; and, once there, the greater part is
evaporated. Little seems to leave the lake, which would consequently
make a very poor reservoir. The land rises from the lake in gently
undulating downs as a rule. Wherever observed by Mr. Dupuis, the lake
was shallow. There are many islands and some of them considerable ones.
The rivers feeding the lake are the following:--the Abai discharging 9
cubic metres per second in January 1903, the Reb 2 cubic metres, the
Gumara 2, the Magetch 0·3, the Arno Garno 0·3, the Gelda 0·5, the Unfraz
1·2, and many smaller streams say 1·7, or 17 cubic metres per second in
all. This of course was in the dry season. Mr. Dupuis considers the
evaporation as 4 millimetres per day.

Between Lake Tsana and Rosaires, on a length of about 750 kilometres the
Blue Nile falls some 1260 metres; between Rosaires and Sennar, on a
length of 270 kilometres, it falls about 60 metres, and between Sennar
and Khartoum on a length of 345 kilometres it falls about 50 metres. The
cross sections of the river at Wad Medani, 200 kilometres above
Khartoum, and at Khartoum are given on Plate IX.

In flood and early winter the river is navigable up to the Rosaires
cataract. The width of channel may be considered as varying between 350
and 700 metres with an average width of 500 metres. The river rises from
9 to 12 metres in flood and has a velocity in high floods of 3 metres
per second. Rivers with such velocities scour out their beds very
severely in high floods and deposit silt in low floods, and for the
discharges below 5 metres, cross sections should be annually established
and discharge tables made depending on the sections. The summer
discharge varies from 100 to 300 cubic metres per second and the flood
from 7,500 to 12,500 cubic metres per second. The behaviour of the river
is shown in Tables 24 and 25. The beginning of May is generally low
water and the beginning of September high water. The winter discharge
may be taken as 500 cubic metres per second.

The tributaries south of Rosaires are the following:--on the right bank,
the Folassa, the Durra, the Fatsam, the Bir and the Temsha, veritable
torrents; and on the left bank, numerous streams from north and
north-west of Addis Ababa, the Anjur, and the Didessa, the latter from
100 to 150 metres wide. North of the last is the Tumat. The Didessa is
about 350 kilometres long and the Tumat 200. It is not at all improbable
that in the valley of the Didessa far better reservoir sites could be
found than at Lake Tsana. Capt. Lyons tells me that there are important
reaches here with very little slope. North of Rosaires there are two
important tributaries on the right bank, the Dinder, north of Sennar,
and the Rahad, just north of Wad Medani. Both these streams run only in
flood and are dry in winter and summer. The Dinder has a bed width of
about 120 metres, depth 4 metres in good flood and a velocity of 2
metres per second, which gives a discharge of about 1000 cubic metres
per second in a high flood. The Rahad has a bed width of 60 metres,
depth of 3 metres in a good flood and a velocity of 2 metres per second,
which gives a discharge of 400 cubic metres per second in a good flood.
The deltas of the Blue Nile, the Dinder and the Rahad are formed of the
richest Nile mud. Such soil is rich in lime, potash and phosphates, but
is poor in nitrates.

[Illustration: PLATE VII

Lith. Sup. Dep. Cairo.

THE OUTLET OF LAKE TSANA

_From a rough Survey_

Scale 1 : 30.000]

The velocity of the Blue Nile may be taken as 75 centimetres per second
in low supply and 3 metres per second in high flood.


20. =The Atbara.=--The Atbara river flows into the Nile at El-Damer,
south of Berber. It is essentially a torrent fed by the rains of
north-eastern Abyssinia. The rains here begin early and end early, so
that the Atbara is in high flood in August and falls quickly through
September. Its floods last from June to October and the river is dry for
the remaining months of the year. By dry it is meant that there is no
running water, for the bed of the river contains numerous pools of
water, which are nearly always deep and often very extensive.

Mr. Dupuis has given a rough longitudinal section of the Atbara river.
Rising within 16 kilometres of Lake Tsana, at a height of about 2000
metres above sea level, in its first 300 kilometres it falls 1500 metres
to 530 metres above sea level, where it is met by the Salaam river. In
the next hundred kilometres it falls 40 metres and is joined by the
Settit river, a larger and more permanent stream than the Atbara itself.
Sixty kilometres lower down is the Khasm-el-Girba gauge, just upstream
of Fasher and about 420 kilometres from the Nile. Two hundred kilometres
below the Settit junction and about 280 kilometres from the Nile is
Gosrejeb, and 150 kilometres lower down Adarma. Finally, after a total
length of about 880 kilometres, the Atbara flows into the Nile.

The Settit junction is about 490 metres above sea level, Fasher 470
metres, Gosrejeb 410, Adarma 380, and El-Damer about 365 metres above
sea level. In the last 280 kilometres there is therefore a fall of 45
metres or about ¹⁄₆₀₀₀. In this reach the river has a width of about 330
metres and depth in flood of 6 metres.

Tables 24 and 25 give the behaviour of the river. In 1902 and 1904, two
very low years, the maximum discharge was about 2000 cubic metres per
second, and in 1903 about 3000 cubic metres. In high floods the Atbara
can discharge 5000 cubic metres per second.

The principal tributaries of the Atbara are the Salaam and Settit
already mentioned. On its right bank between Gosrejeb and Adarma it is
joined by the Gaash river, which flows past Kassala and loses itself in
the deserts. In years of extraordinary rainfall the Gaash reaches the
Atbara. The Gaash at Kassala has a width of 150 metres, depth of 1 metre
and approximate discharge of 300 cubic metres per second in an ordinary
flood. It has a course of about 160 kilometres before it disappears in
the desert.


21. =The Nile from Khartoum to Assuân.=--The Nile begins its course
without any gauge to record its varying height. A gauge north of
Omdurman, another upstream of the 6th cataract and a third downstream of
the cataract are badly needed. Until these three gauges are erected and
recorded, and another erected and recorded on the Blue Nile at Kamlin,
about 100 kilometres above Khartoum, the behaviour of the Nile and its
tributaries at their junction will never be exactly understood. Making
use of the information which is obtainable, we may say that the Blue
Nile is generally at its lowest between the 15th April and 15th May with
a mean low-water discharge of about 200 cubic metres per second, falling
to nearly zero in certain years; it is at its highest between the 15th
August and 15th September with a mean maximum discharge of some 10,000
cubic metres per second, rising to 13,000 and falling to 6,500 in
maximum and minimum years. If the larger figure is correct, the Blue
Nile bank at Khartoum is over a metre too low, and the town is liable to
be flooded out. If reference is made to Plate VIII it will be seen that
the flood of the Blue Nile in July, August and September travels up the
White Nile, holds back its waters and converts the valley of the White
Nile into a flood reservoir. When the Blue Nile falls rapidly in October
and November, the discharge of the Nile is maintained by the stored-up
waters in the White Nile and by the White Nile flood which has slowly
travelled down its almost level bed. Table 24 shows this more clearly
than any description could. I do not think that the maximum discharge of
the Main Nile on any given day is ever equal to the maximum discharge of
the Blue Nile.

The Nile between Khartoum and Berber has a channel wider and deeper than
that between Wady Halfa and Assuân and a gentler current. I have not
taken, or seen any discharges which have been taken in this reach, but
judging from what I saw I should say the channel was 800 metres wide on
the average. At a distance of 86 kilometres from Khartoum is the
Shabluka or 6th cataract. Here the Nile descends 6 metres on a length of
18 kilometres. Two hundred and twenty kilometres below the cataract the
Atbara flows into the Nile and repeats on a very small scale what the
Blue Nile does at Khartoum. The Atbara is a flood torrent and is dry
from October to May. In flood it discharges from a low maximum of 1,700
to a high maximum of 5,000 cubic metres per second, with a mean maximum
of 3,500 cubic metres.

[Illustration: PLATE VIII.

BLUE & WHITE NILE GAUGES

FLOOD OF 1903.

BLUE & WHITE NILE GAUGES

FLOOD OF 1904.

Lith. Sur. Dep. Cairo.]

In this reach the Nile has a maximum range of 8¹⁄₂ metres and an
ordinary range of 7 metres.

Twenty-four kilometres downstream of the Atbara junction is Berber, and
45 kilometres downstream of Berber is the beginning of the 5th cataract,
which has a length of 160 kilometres and a drop of 55 metres with three
principal rapids, the Solimania, Baggâra and Mograt. The village of Abu
Hamed is situated at the foot of this Cataract. Between Abu Hamed and
Dongola is the 4th Cataract, which begins at a point 97 kilometres
downstream of Abu Hamed, and has a length of 110 kilometres with a drop
of 49 metres. In this series of rapids are the Um Dâras and Guerendid.
Between the 4th and 3rd Cataracts is a reach of 313 kilometres on a
slope ¹⁄₁₂₀₀₀. On this reach is the town of Dongola. The 3rd Cataract
has a length of 72 kilometres and a drop of 11 metres with the Hannek
and Kaibâr rapids, surveyed and levelled by De Gottberg in 1857.
Upstream of the Hannek rapid, on the left bank of the Nile, is the
termination of the long depression in the deserts which goes by the name
of the Wady-el-Kab and is considered by many as lower than the Nile
valley. Between the 3rd and 2nd Cataracts is an ordinary reach of 118
kilometres. West of this part of the Nile are the Selima Wells and
according to some travellers an old abandoned course of the Nile
slightly above the present high level of the river. This waterless river
is said to terminate in the Oasis of Berys which is separated from the
Khargeh Oasis by a limestone ridge.

The 2nd Cataract, known as the “Batn-el-Haggar” or “Belly of Stone,” has
a length of 200 kilometres and a drop of 66 metres with the rapids of
Amâra, Dal, Semna and Abka. At Semna are the rocks where Lepsius
discovered the Nile gauges cut by one of the Pharaohs some 4,000 years
ago. The Nile flood recorded there is 8 metres higher than any flood of
to-day. As the Nile at Semna could be very easily barred by a dam, it
struck me when I was there in 1892 that probably King Amenemhat (of Lake
Mœris fame) had tried to bar the river with a dam in the hope of
creating a reservoir. At Wady Halfa, near the foot of the 2nd Cataract,
a masonry gauge divided into metres has been erected and read since
1877. Its accidental zero is R. L. 116.69 and the mean low-water level,
or true zero, is R. L. 117.89. Between the 1st and 2nd Cataracts, the
Nile has a length of 345 kilometres and a slope of ¹⁄₁₂₅₀₀. The mean
width of the river is 500 metres, and the mean depths in flood and
summer are 9 and 2 metres. The velocity in summer falls to 50
centimetres per second and rises to 2 metres per second in flood. The
river in this reach is generally within sandstone, and the greater part
is provided with gigantic spurs on both banks. These spurs perform the
double work of collecting soil on the sides in flood and training the
river in summer. They were probably put up by the great Rameses 3,000
years ago, as some of the most massive of them have evidently been
constructed to turn the river on a curve out of its natural channel on
to the opposite side in order to secure deep water in front of Rameses’
temple of Jerf Husain (“Jerf” means steep, scoured bank). The spurs have
been constructed with care, and as the courses of roughly-dressed stone
can be examined at fairly low water (I have never seen them at
absolutely low water) it is evident that there has been no great
degradation of the bed during the last 2,000 or 3,000 years. The first,
or Assuân Cataract, has a drop of 5 metres on a length of 5 kilometres.

From Khartoum to Assuân, on a total length of 1809 kilometres, there are
565 kilometres of so-called cataracts with a total drop of 192 metres,
and 1,244 kilometres of ordinary channel with a total drop of 103
metres.

At the head of the 1st Cataract is the Assuân dam, regulated on for the
first time in October 1902. It has 140 openings of 2 metres × 7 metres
and 40 openings of 2 metres × 3¹⁄₂ metres.

At the foot of the 1st Cataract, opposite the town of Assuân, on the
Island of Elephantine, has stood a Nile gauge from very ancient times.
An officer belonging to the Roman garrison in the time of the Emperor
Severus marked an extraordinarily high flood on the gauge. The maximum
flood-mark at the time of the visit of Napoleon’s French savants was
however 2.11 metres higher than the above. As the middle of Severus’
reign was A.D. 200, and the visit of French savants A. D. 1800, they
concluded that the bed and banks of the Nile had risen 2.11 metres in
1600 years or 0.132 metres per 100 years. The new gauge divided into
cubits and twenty-fourths was erected in 1869 and has been recorded
daily since then (a cubit = 54 centimetres). The accidental zero of the
gauge is R. L. 84.16. The mean low-water level or true zero is R. L.
85.00.

[Illustration: PLATE X.

LONGITUDINAL SECTION OF THE NILE FROM WADY HALFA TO GEBEL SILSILAH

Lith. Sur. Dep. Cairo.

CROSS SECTION OF THE NILE VALLEY NEAR IBRÎM

CROSS SECTION OF THE NILE VALLEY NEAR ASSUÂN

TYPICAL CROSS SECTION UPSTREAM OF ASSUÂN DAM]


22. =The Nile from Assuân to the Barrage.=--From Assuân to the Barrage,
the length of the river is 973 kilometres in summer and 923 in flood.
The slope in summer is ¹⁄₁₃₀₀₀ and in flood ¹⁄₁₂₂₀₀ The mean fall of the
valley is ¹⁄₁₀₈₀₀. The slopes vary in the different mean reaches, the
least being ¹⁄₁₄₈₀₀ in the Kena Mudiria and the greatest ¹⁄₁₁₄₀₀ in Beni
Suef. In a high flood with a rise of 9 metres at Assuân, the rise in
Kena will be 9.5 metres and only 8.2 in Beni Suef. Table 42 gives the
mean areas of cross sections of the Nile, while table 44 gives the mean
widths. Neglecting spill channels, we may state that in a high flood the
mean area of the section of the Nile is 7,500 square metres and the mean
width 900 metres. In the Kena Mudiria, the area is 7,000 square metres
and the width 800 metres, while in Beni Suef the mean area is 8,000
square metres and the mean width 1,000 metres. Speaking generally it may
be stated that where the Nile valley is narrow the slope of the river is
small, its depth great and width contracted; while where the valley is
broad the slope is great, the depth small and the width enlarged. The
mean velocity in flood ranges between 2.0 metres and 1.0 metre per
second, while the velocity in summer varies from 0.5 to 0.9 metre per
second. We may say that the Nile in soil has a natural section whose
width in flood is 110 times its depth, while its mean velocity is 1.50
metres per second.

The natural canals, which take off the river and which never silt, have
a mean velocity of some 65 centimetres per second, while the proportion
of width to depth is about 12 to 1. Artificial canals of this section do
not silt if their velocities are 80 centimetres per second, while
silting takes place as readily when the velocity is greater as when it
is less than the above. In muddy streams, like the Nile in flood,
certain velocities demand certain proportions of width to depth, and if
these are not given to it, they will make it for themselves by eating
away the sides if they can, or, if they cannot eat away the sides, by
silting up and raising the bed.

To the north of Assiout is situated the Assiout weir or barrage across
the Nile with 111 openings of 5 metres and 10 metres depth of water in
high flood. It was regulated on for the first time in August 1902.

On Roda island, opposite Cairo, has stood a gauge from the earliest
times. It has been frequently reconstructed. The present gauge is
reputed to have been erected in A.D. 861 with its zero at the same level
as a more ancient one whose readings have been preserved since A.D. 641.
When the gauge was constructed, a reading of 16 cubits meant the lowest
level at which flood irrigation could be insured everywhere. The level
to-day is 20¹⁄₂ cubits on the gauge and the difference between them is
1.22 metres. As 1,026 years have elapsed since the construction of the
gauge it means a rise of 12 centimetres per 100 years. This is slightly
under the rise calculated at Assuân by the French savants.

The following table gives the means of the maximum flood and low water
levels per century:--

   7th century 17.5 R. L. flood 11.0 R. L. low water 6.5 Difference.
   8th    „    17.4     „       11.1        „        6.3      „
   9th    „    17.5     „       11.2        „        6.3      „
  10th    „    17.5     „       11.3        „        6.2      „
  11th    „    17.5     „       11.4        „        6.1      „
  12th    „    17.7     „       11.5        „        6.2      „
  13th    „    17.7     „       11.6        „        6.1      „
  14th    „    17.9     „       11.7        „        6.2      „
  15th    „    18.2     „       11.8        „        6.4      „
  16th    „    18.4     „       11.9        „        6.5      „
  17th    „    18.8     „       12.0        „        6.8      „
  18th    „    19.1     „       12.1        „        7.1      „
  19th    „    19.5     „       12.2        „        7.3      „

It is evident from the above that the head of the Delta, or the
bifurcation of the Nile, was much nearer to Cairo in early days than
just now, and the last three centuries have seen great changes. The fall
of watersurface is very considerable at every bifurcation, and the
difference between mean high and low supply at the Barrage to-day is 6.0
metres against 7.2 metres at Cairo. Judging from the above figures, I
should say that from the 7th to the 13th century the bifurcation was
gradually approaching Cairo, while since the 13th it has been
receding.

[Illustration: PLATE XII.

LONGITUDINAL SECTION OF THE NILE FROM ASSUAN TO CAIRO

ALONG CENTRE LINE OF FLOOD

Lith. Sur. Dep. Cairo.

CROSS SECTIONS OF THE NILE VALLEY IN EGYPT]

The following table gives the highest and lowest floods at Cairo in
intervals of 25 years from A.D. 639 to A.D. 1904.

The gauges are in pics and kirats and are referred to mean low water or
R. L. 12·25 metres above mean sea.

  =========+=============================+=============================+
    Years  |       HIGHEST MAXIMUM       |       LOWEST MAXIMUM        |
    A. D.  +-----+-------+------+--------+-----+-------+------+--------+
           |Pics.|Kirats.|Metres| Metres |Pics.|Kirats.|Metres| Metres |
           |     |       |R. L. |referred|     |       |R. L. |referred|
           |     |       |      |to zero |     |       |      |to zero |
           |     |       |      |at R. L.|     |       |      |at R. L.|
           |     |       |      |  12·25 |     |       |      |  12·25 |
  ---------+-----+-------+--- --+--------+-----+-------+------+--------+
   639- 650|  19 |   ..  | 18·16|  5·91  |  14 |  21   | 16·74|  4·49  |
   651- 675|  19 |   23  | 18·42|  6·17  |  15 |  12   | 17·07|  4·82  |
   676- 700|  18 |   17  | 18·08|  5·83  |  13 |   6   | 15·87|  3·62  |
   701- 725|  18 |   22  | 18·14|  5·89  |  13 |  18   | 16·13|  3·88  |
   726- 750|  18 |   13  | 18·04|  5·79  |  14 | ¹⁄₂   | 16·28|  4·03  |
   751- 775|  18 |   10  | 18·00|  5·75  |  14 |  19   | 16·70|  4·45  |
   776- 800|  18 |    4  | 17·93|  5·68  |  14 |   1   | 16·29|  4·04  |
   801- 825|  17 |   18  | 17·82|  5·57  |  14 |   2   | 16·31|  4·06  |
   826- 850|  17 |   12  | 17·76|  5·51  |  13 |   5   | 15·85|  3·60  |
   851- 875|  18 |    8  | 17·98|  5·73  |  15 |  15   | 17·15|  4·90  |
   876- 900|  17 |   22  | 17·86|  5·61  |  14 |  22   | 16·76|  4·51  |
   901- 925|  18 |    1  | 17·90|  5·65  |  13 |   4   | 15·83|  3·58  |
   926- 950|  19 |   ..  | 18·16|  5·91  |  14 |  17   | 16·65|  4·40  |
   951- 975|  18 |    5  | 17·94|  5·69  |  14 |  19   | 16·60|  4·45  |
   976-1000|  26 |   23  | 21·65|  9·40  |  15 |   2   | 16·85|  4·60  |
           +-----+-------+------+--------+     |       |      |        |
  1001-1025|  19 |    8  | 18·25|  6·00  |  14 |   9   | 16·47|  4·22  |
  1026-1050|  18 |    6  | 17·95|  5·70  |  15 |   9   | 17·01|  4·76  |
  1051-1075|  17 |   18  | 17·71|  5·46  |  12 |   3   | 15·30|  3·05  |
           |     |       |      |        +-----+-------+------+--------+
  1076-1100|  18 |   16  | 18·07|  5·82  |  13 |  17   | 16·11|  3·86  |
  1101-1125|  19 |    1  | 18·17|  5·92  |  16 |  12   | 17·48|  5·23  |
  1126-1150|  18 |   18  | 18·09|  5·84  |  16 |   9   | 17·45|  5·20  |
  1151-1175|  18 |   18  | 18·09|  5·84  |  15 |   1   | 16·83|  4·58  |
  1176-1200|  18 |   14  | 18·05|  5·80  |  12 |  21   | 15·68|  3·43  |
           |     |       |      |        +-----+-------+------+--------+
  1201-1225|  18 |    8  | 17·98|  5·73  |  15 |   7   | 16·96|  4·71  |
  1226-1250|  18 |    8  | 17·98|  5·73  |  14 |  ..   | 16·27|  4·02  |
  1251-1275|  18 |   17  | 18·08|  5·83  |  16 |  12   | 17·48|  5·28  |
  1276-1300|  19 |    7  | 18·24|  5·99  |  15 |  18   | 17·22|  4·97  |
  1301-1325|  18 |   19  | 18·10|  5·85  |  16 |   2   | 17·37|  5·12  |
  1326-1350|  18 |   21  | 18·13|  5·88  |  16 |   5   | 17·40|  5·15  |
  1351-1375|  24 |   ..  | 20·05|  7·80  |  16 |  18   | 17·55|  5·30  |
           +-----+-------+------+--------+     |       |      |        |
  1376-1400|  20 |    3  | 18·46|  6·21  |  16 |  13   | 17·50|  5·25  |
  1401-1425|  20 |   12  | 18·56|  6·31  |  16 |  13   | 17·50|  5·25  |
  1426-1450|  20 |   21  | 18·67|  6·42  |  15 |   7   | 16·96|  4·71  |
  1451-1475|  18 |    8  | 17·98|  5·73  |  .. |  ..   |   .. |   ..   |
  1476-1500|  20 |   21  | 18·67|  6·42  |  19 |  17   | 18·55|  6·30  |
  1501-1525|  20 |   16  | 18·61|  6·36  |  16 |       | 17·35|  5·10  |
  1526-1550|  .. |   ..  |   .. |   ..   |  .. |  ..   |   .. |   ..   |
  1551-1575|  .. |   ..  |   .. |   ..   |  .. |  ..   |   .. |   ..   |
  1576-1600|  26 |   ..  | 21·13|  8·88  |  18 |   8   | 17·98|  5·73  |
           +-----+-------+------+--------+     |       |      |        |
  1601-1625|  24 |    5  | 20·16|  7·91  |  17 |  23   | 17·88|  5·63  |
           +-----+-------+------+--------+     |       |      |        |
  1626-1650|  19 |   ..  | 18·16|  5·91  |  15 |  ..   | 16·81|  4·56  |
  1651-1675|  22 |   ..  | 18·97|  6·72  |  .. |  ..   |   .. |   ..   |
           +-----+-------+------+--------+     |       |      |        |
  1676-1700|  24 |   ..  | 20·05|  7·80  |  22 |  ..   | 18·97|  6·72  |
           +-----+-------+------+--------+     |       |      |        |
  1701-1725|  23 |    4  | 19·60|  7·35  |  16 |  ..   | 17·35|  5·10  |
  1726-1750|  24 |   12  | 20·32|  8·07  |  20 |  14   | 18·58|  6·33  |
           +-----+-------+------+--------+     |       |      |        |
  1751-1775|  24 |   12  | 20·32|  8·07  |  18 |  17   | 18·08|  5·83  |
           +-----+-------+------+--------+     |       |      |        |
  1776-1800|  24 |   ..  | 20·05|  7·80  |  12 |  12   | 15·49|  3·24  |
           +-----+-------+------+--------+     |       |      |        |
  1801-1825|  22 |   ..  | 18·97|  6·72  |[5]8 |  ..   | 13·14|  0·89  |
           |     |       |      |        +-----+-------+------+--------+
  1826-1850|  24 |    9  | 20·26|  8·01  |  18 |  23   | 18·15|  5·90  |
           +-----+-------+------+--------+     |       |      |        |
  1851-1875|  26 |   12  | 21·40|  9·15  |  19 |  13   | 18·30|  6·05  |
           +-----+-------+------+--------+     |       |      |        |
  1876-1900|  26 |    6  | 21·27|  9·02  |  17 |   3   | 17·65|  5·40  |
           +-----+-------+------+--------+     |       |      |        |
  1901-1904|  .. |   ..  | 19·18|  6·93  |  .. |  ..   | 18·02|  5·97  |
  =========+=====+=======+======+========+=====+=======+======+========+

  =========+========+==============
    Years  |N^{o} of|Remarks.
    A. D.  | years  |
           |  re-   |
           | corded.|
  ---------+--------+--------------
   639- 650|11 years|
   651- 675|25   „  |
   676- 700|25   „  |
   701- 725|25   „  |
   726- 750|25   „  |
   751- 775|25   „  |
   776- 800|25   „  |
   801- 825|25   „  |
   826- 850|25   „  |
   851- 875|25   „  |
   876- 900|25   „  |
   901- 925|25   „  |
   926- 950|25   „  |
   951- 975|24   „  |
   976-1000|25   „  |Max. year 199
           |        |
  1001-1025|25   „  |
  1026-1050|25   „  |
  1051-1075|25   „  |Min. year 1070
           |        |
  1076-1100|24   „  |
  1101-1125|25   „  |
  1126-1150|24   „  |
  1151-1175|25   „  |
  1176-1200|25   „  |Min. year 1199
           |        |
  1201-1225|25   „  |
  1226-1250|25   „  |
  1251-1275|23   „  |
  1276-1300|25   „  |
  1301-1325|25   „  |
  1326-1350|25   „  |
  1351-1375|24   „  |Max. year 1359
           |        |
  1376-1400|25   „  |
  1401-1425|24   „  |
  1426-1450|23   „  |
  1451-1475| 1   „  |
  1476-1500| 2   „  |
  1501-1525|19   „  |
  1526-1550|  ..    |
  1551-1575|  ..    |     ..
  1576-1600|11 years|Max. year 1587
           |        |
  1601-1625|19   „  |    „     1602
           |        |
  1626-1650| 3   „  |
  1651-1675| 1   „  |Max. year 1669
           |        |
  1676-1700| 3   „  |    „     1697
           |        |
  1701-1725|18   „  |
  1726-1750|24   „  |Max. year 1738
           |        |
  1751-1775|25   „  |    „     1756
           |        |
  1776-1800|25   „  |    „     1779
           |        |
  1801-1825| 3   „  |Min. year 1809
           |        |
  1826-1850|25   „  |Max. year 1850
           |        |
  1851-1875|25   „  |    „     1874
           |        |
  1876-1900|25   „  |    „     1878
           |        |
  1901-1904| 4   „  |Min. year 1877
  =========+========+==============

  [5] There is an error here in the records.

At Assuân the Nile has a mean range of 7.90 metres between high and low
supply, with a maximum of 9.80 metres and a minimum of 6.40 metres. The
high supply varies between 13,200 and 6,500 cubic metres per second,
with a mean of 10,000 cubic metres per second, while the low supply
varies between 350 and 1400 cubic metres per second with a mean of 590
cubic metres per second. September is generally the highest month and
May the lowest. The mean low water level is R. L. 85.00.

At Cairo the Nile has a mean range of 7.00 metres with a maximum of 9.6
metres and a minimum of 5.3 metres. The high supply varies between
12,000 and 4,800 cubic metres per second with a mean of 7,600 cubic
metres per second, while the low supply varies between 1,300 and 250
cubic metres per second, with a mean of 500 cubic metres per second.
October is the highest month and June the lowest. The mean low water
level is at R. L. 12.25.

[Illustration: PLATE XI.

CROSS SECTIONS OF THE NILE & ITS TRIBUTARIES

_Horizontal Scale 1 : 2.000_

_Vertical Scale 1 : 500_

Lith. Sur. Dep. Cairo.

No. 19. _River Rahad at Khor Abou Seghire 20 km. above the Nile
junction_

No. 20. _Atbara River at Khashim al Girba 410 km. from Nile_

No. 21. _Atbara River at Khor Abadar 25 km. from Nile_

No. 22. _Nile at Manfalout_

No. 23. _Rosetta Branch at Khatatba_

No. 24. _Damietta Branch at Benha_]

Tables 41 to 52 refer to the Nile between Assuân and the Barrage at the
head of the Delta proper.

Table 46 gives the Reduced Level of the mean low water level of the Nile
at various points between Assuân and Cairo. If, for example, it is known
that the water surface at any time of the year at Assiout is R. L.
50.80, we know the mean low water by the Irrigation Department levels is
45.05. The gauge is therefore 5.75, and by turning to Table 37 we know
the discharge.

Table 37 gives the discharges of the river for gauges referred to the
mean low water level. Between Esna and Kena the table is in excess of
the truth, and between Assiout and Beni-Suef it is slightly under. Taken
all round the table is reliable, calculated from the means of hundreds
of discharges and carefully prepared.

Table 45 gives the slope of the water surface of the Nile in flood and
in summer between Assuân and Cairo. Owing to the more winding track of
the low supply than of the flood waters, the former is 948 kilometres
and the flood 900. The slope in summer is ¹⁄₁₃₀₀₀ and in high flood
¹⁄₁₂₂₀₀.

The other tables need no explanation.


23. =The Rosetta and Damietta Branches.=--Plates XVII and XVIII give
longitudinal sections of the two branches of the Nile and their cross
sections are given on Plate XI.

During winter, summer, and low floods, regulation at the Barrage
interferes with the natural discharges of the two branches. The Damietta
branch is gradually silting up and decreasing in size, while the Rosetta
branch scours in high floods. The mean width of the Rosetta branch is
500 metres, and the mean area of the section in flood is 4000 square
metres. The mean width of the Damietta branch is 270 metres and the mean
section 2700 square metres. The mean velocity of the floods range from
1.00 metre to 1.60 metres per second. In summer the branches are
hermetically closed at their heads and receive only the water which
filters into them from the subsoil. This in the Rosetta branch amounts
to 20 cubic metres per second, and less in the Damietta branch. It may
be noted here that at Cairo the girder bridge at Kasr-el-Nil is 403
metres between the abutments and the smaller bridge is 178 metres,
making a total width of 581 metres. The width of the Kafr Zayat bridge
on the Rosetta branch is 530 metres, while the old Benha bridge on the
Damietta branch is 285 metres. The average depth of water in flood in
the two branches may be taken as 7 metres.

The barrage at the head of the Rosetta branch has 61 openings of 5
metres each and one lock 15 metres wide and the other 12 metres. They
are all open in high flood. The Damietta barrage has 61 openings of 5
metres and one lock of 12 metres. The depth of water in a high flood is
9 metres. The Rosetta barrage has 10 openings too few, and the Damietta
barrage 15 openings too many.

Before the construction of the Barrage in the middle of the 19th
century, the maximum discharges of the two branches at the head of the
Delta were nearly the same. A little lower down, however, the Rosetta
branch had considerably more water than the Damietta. About 2 kilometres
below the Barrage there was a branch called the Shalakan branch which
flowed from the Damietta into the Rosetta branch. About 20 kilometres
below the Barrage, the Bahr Ferounieh took about ¹⁄₃ the total discharge
of the Damietta branch and led it into the Rosetta branch. Both these
were closed by Mehemet Ali, while at the same time the Bahrs Sirsawiah,
Baguria, Shebin, Khadrawiah, Moes, Um-Salama, Bohia and Sogair were also
completely closed or provided with regulating heads, which very
considerably diminished their discharge. During the time that they had
been open the Damietta branch had lost water at every kilometre as it
approached the sea, and though 400 metres wide at the head it had a
channel only 200 metres wide in its lower reaches. The Rosetta branch on
the other hand received the tail waters of many Bahrs and had only one
escape, the Bahr Saidi near its tail.

The closing of so many escapes on the Damietta branch has caused this
branch in its upper reaches to carry so much water that its tail reaches
can not carry it without having the surface of the water raised
inordinately and dangerously above the level of the country. An
examination of the longitudinal sections will show that while the
Rosetta branch in its middle reaches is from 1.50 to 2.00 metres above
the level of the country in a high flood, the Damietta branch is from
2.50 to 3.00 metres. They will also show how the slope in the early
reaches of the Damietta branch is considerably less than that in the
early reaches of the Rosetta branch, which results in the gradual
silting up of the former as already noted. The Karanain regulator at the
head of the old Bahr Shebin, taking from the Damietta branch below the
Bahr Ferouniah, was built in 1842 by Linant Pasha, with its wing wall 60
centimetres higher than any previous flood. By 1870 the Damietta branch
had risen 70 centimetres above the wing wall as measured by Linant
Pasha. In 1878, though the Damietta branch was relieved by the Gizeh
breach in the left bank of the Main Nile which drained into the Rosetta
branch, the flood water surface of the Damietta branch at Karanain was
1.50 metres above the wing wall.

[Illustration: PLATE XVII.

LONGITUDINAL SECTION OF THE ROSETTA BRANCH

_Longitudinal Scale 1 : 100,000_

_Vertical Scale 1 : 1,000_

_Measurement along the right bank_]

[Illustration: PLATE XVIII.

LONGITUDINAL SECTION OF THE DAMIETTA BRANCH

_Longitudinal Scale 1 : 100,000_

_Vertical Scale 1 : 1,000_

_Measurement along the left bank_]

The maximum, minimum and mean floods in the Rosetta branch are 6,500,
2,600 and 4,000 cubic metres per second. In the Damietta branch they are
4,600, 1,300 and 2,300 cubic metres per second respectively.




CHAPTER III.

The utilisation of the Nile.


24. =The Nile in flood.=--We are now in a position to apply our
knowledge of the Nile and its tributaries to an examination of the
behaviour of the rivers in flood and in time of low supply. Lake
Victoria, the Victoria Nile, and Lake Albert may all be considered as
the great equatorial regulators of the Nile. The river, as a river,
begins at the outlet of Lake Albert, i.e., at the head of the Albert
Nile. Generally at its lowest in April, it rises gradually and reaches
its maximum in November. The mean minimum of 600 cubic metres per second
is gradually increased to its mean maximum of 900 cubic metres. The
regulating effect of the lakes is very evident.

Between Lake Albert and Gondokoro the heavier rains begin late in April
and with a break in June and July continue to November. The mean minimum
discharge of 600 cubic metres per second in April is increased by
alternating rises and falls to the mean maximum of 1600 cubic metres per
second in September, which has disappeared by the end of November, when
the water of Lake Albert alone remains in the river.

The Gazelle river in no way affects the flood or the low supply. Its
great function is to maintain the levels of the great swamps between
latitudes 7° and 9°, saturate the soil, and prevent the complete
disappearance of the waters of the Albert Nile between January and May.
The functions this river performs are humble ones, but deprived of its
aid, the Nile north of Khartoum would frequently be dry in April and
May.

The Albert Nile at its tail just upstream of the mouth of the Sobat is
at its lowest in April and May with a mean low discharge of 375 cubic
metres per second, when it is joined by the Sobat river with an
approximate mean low discharge of 125 cubic metres per second; making a
joint discharge for the head of the White Nile of 500 cubic metres per
second as a mean minimum. Now begins one of the most interesting
operations of any in the whole valley of the Nile, exceeded only in
interest by what happens at Khartoum lower down. The Albert Nile and the
Sobat river both rise together, the Albert Nile on a very gentle slope
freely overflowing its banks in the Sudd region, and the Sobat river
confined within its channel during its highest floods. The White Nile
has a very gentle slope, little carrying capacity and is quite incapable
of taking on both floods. The water rises at the junction and the Sudd
region becomes a reservoir flooded to a depth of 3 metres. As the Sobat
river increases its discharge gradually from 75 cubic metres per second
in April to 1000 cubic metres per second in October and November (for it
is confined to its channel), the Albert Nile decreases the actual
discharge it sends down the White Nile and increases what it spreads
over the Sudd region. The Albert Nile, having increased its quota for
the White Nile from 375 in April to 450 cubic metres per second in
September, gives less in October and November and gradually passes on
its waters in December, January and February when the Sobat has fallen.

The White Nile at its head near Tewfikieh has its mean minimum of 500
cubic metres per second in April, and increases slowly to its mean
maximum of 1500 cubic metres per second in December. During this
interval its water surface is raised by 3·50 metres. This water travels
very slowly on to Khartoum, where the mean minimum is 450 cubic metres
per second in May, the slope is very insignificant, and the trough of
the river is 1500 metres wide.

At Khartoum the White Nile meets the Blue Nile. No greater contrast
exists in the world. If maximum discharges are alone considered, the
little finger of the Blue Nile is thicker than the loins of the White
Nile.

The Blue Nile is at its lowest on the 1st May with a mean minimum supply
of 200 cubic metres per second rising to a mean maximum flood of 10,000
cubic metres per second on the 1st September. The flood has fallen to
2000 cubic metres per second by the middle of November.

Up to the middle of July the Blue and White Niles keep increasing their
discharges steadily at Khartoum, but after that date the Blue Nile gauge
and discharge rise rapidly together, and the Blue Nile not only feeds
the Main Nile, but flows up the White Nile and arrests its discharge, so
that at Duem, 200 kilometres above Khartoum, the White Nile discharge
decreases in July and August while the Blue Nile is steadily flowing up
the White Nile valley and converting it into a reservoir for the Nile in
winter. It is only after the 15th September, when the Blue Nile has
begun to fall steadily and continuously that the White Nile discharge
really commences and reaches its mean maximum of some 2000 cubic metres
per second in October.

The mean minimum discharge of the Nile of 650 cubic metres per second at
Khartoum is obtained on the 1st May and the mean maximum of 9000 cubic
metres per second on the 1st September. Fed by the White Nile reservoir
the river falls comparatively slowly. Whether this peculiar relation of
the two rivers to each other could not be taken advantage of to increase
the supply in December, January and February, and decrease it in October
and November by means of a regulating dam built across the White Nile at
Khartoum is worthy of study.

I greatly prefer the idea of storing the flood waters of the White Nile
at Khartoum to any storage of the Albert Nile water above the junction
of the Sobat river. A regulator above the Sobat junction would store up
a very considerable quantity of water, but the quality would be very
doubtful and possibly dangerous to health.

At El Damer, south of Berber, the Atbara flows into the Nile. Dry from
January to May, the flood begins in June and is at its maximum as a rule
in the last week of August; with a mean high flood discharge of 3500
cubic metres per second. This water cannot come on to Assuân without
filling up the 200 kilometres downstream of the 6th cataract where the
slope of the Nile is gentle and the river lends itself to being used as
a reservoir. It is owing to the fact that none of the main feeders of
the Nile flow in immediately below cataracts that the rise and fall of
the Nile in Egypt, is so regular and constant. If the Sobat, Blue Nile
and Atbara all flowed into the White or Main Niles below cataracts we
should have floods in Egypt whose sudden changes of level and
fluctuations would be an unending source of danger to the country.

It is owing to the earliness of the Atbara high flood and the
comparative lateness of the Nile high flood, that the ordinary maximum
discharge of the Nile at Assuân is only 10,000 cubic metres per second.
This is generally on the 5th September. When the monsoon is early the
maximum at Assuân is reached before or on the 5th September; when the
monsoon is late the maximum is reached about the 20th September. An
early maximum at Assuân is generally followed by a low summer, while a
late maximum is generally followed by a high summer supply. Only once
has this rule been broken and that was in 1891 when there were two
maxima, one on the 4th September and another on the 27th. In this year
there must have been an extraordinary fall of rain in Abyssinia in
September, for the flood of the 27th September was very muddy, while as
a rule the river at Assuân is very muddy in August, less so in
September, still less so in October and much less in November when the
White Nile is the ruling factor in the supply of the river.

If the September rains in Abyssinia are very heavy, an ordinary flood
passes Assuân at the end of September and is disastrous for Egypt. This
happened in 1878. Table 26 contains details of this flood, of the
minimum flood year 1877 and the mean of the 20 years from 1873 to 1892.

At Assuân the Nile enters Egypt, and it now remains to consider it in
its last 1,200 kilometres. The mean minimum discharge at Assuân is 590
cubic metres per second and is reached about the end of May. The river
rises slowly till about the 20th July and then rapidly through August,
reaching its maximum about the 5th September, and then falling very
slowly through October and November. The deep perennial irrigation
canals take water all the year round, but the flood irrigation canals
are closed with earthen banks till the 15th August, and are then all
opened. These flood canals, of which there are some 45, are capable of
discharging 2,000 cubic metres per second at the beginning of an
ordinary year, 3,600 cubic metres per second in a maximum year, and have
an immediate effect on the discharge of the Nile. The channel of the
Nile itself and its numerous branches and arms consume a considerable
quantity of water (the cubic contents of the trough of the Nile between
Assuân and Cairo are 7,000,000,000 cubic metres), the direct irrigation
from the Nile between Assuân and Cairo takes 50 cubic metres per second,
130 cubic metres per second are lost by evaporation off the Nile, and
400 cubic metres per second by absorption. Owing to all these different
causes, there is the net result that, from August 15th to October 1st,
the Nile is discharging 2,400 cubic metres per second less at Cairo than
Assuân. During October and November the flood canals are closed, and the
basins which have been filled in August and September discharge back
into the Nile, and in October the Nile at Cairo is discharging 900 cubic
metres per second in excess of the discharge at Assuân and 500 cubic
metres per second in excess in November.

The mean minimum discharge at Cairo is 500 cubic metres per second and
is attained on the 15th of June; the river rises slowly through July and
fairly quickly in August, and reaches its ordinary maximum on the 1st
October when the basins are full and the discharge from the basins is
just beginning. The ordinary maximum discharge at Cairo is about 7,600
cubic metres per second. Through October the Nile at Cairo is
practically stationary, and falls rapidly in November.

North of Cairo are the heads of the perennial canals which irrigate the
Delta proper. The canals, with their feeders lower down, discharge 1,200
cubic metres per second, and the ordinary maximum flood at Cairo of
7,600 cubic metres per second is reduced by this amount between Cairo
and the sea. Of the 6,400 cubic metres per second which remain, 4,100
cubic metres per second find their way to the sea down the Rosetta
branch, and 2,300 cubic metres per second down the Damietta branch.
During extraordinary floods the Damietta branch has discharged 4,300
cubic metres per second and the Rosetta branch 7,000 cubic metres per
second.


25. =The Nile in low supply.=--We have so far considered the Nile in
flood, it now remains to quickly dispose of the low supply. After
reaching its maximum, the Atbara, which is a torrential river, falls
more rapidly than others, and by the end of September has practically
disappeared; after the middle of September the Blue Nile falls quickly,
while the White Nile with its large basin, gentle flow and numerous
reservoirs, falls very deliberately. The mean minimum discharge of the
White Nile at Gondokoro in an ordinary year, at the time of low supply,
is 600 cubic metres per second. Of the Sobat river it is 100 cubic
metres per second. By the time the water reaches Khartoum it is reduced
to 450 cubic metres per second. The mean low supply of the Blue Nile is
200 cubic metres per second, giving a mean low supply to the Nile at
Khartoum of 650 cubic metres per second. The Atbara supplies nothing.
Between Khartoum and Assuân there is a further loss of 60 cubic metres
per second, and the mean low supply delivered at Assuân is 590 cubic
metres per second. In very bad years the discharge at Assuân has fallen
to 400 cubic metres per second.

Lombardini was no untrue prophet when he wrote that he was convinced
that the more carefully the discharges were taken and the results known,
the more would engineers be astonished at the extraordinary amount of
the subsoil water which filtered into the Nile from the head of the
White Nile to the sea, and which gave back to the Nile in the months of
deflux of the river, the water which had percolated into the soil during
the afflux. He predicted that heavy as the evaporation was in April, May
and June in the Nile valley, the influx of subsoil water would be found
to counterbalance it. When we calculate the extent of the water used in
irrigation along the course of the Nile, and compare the discharges at
Tewfikieh, Khartoum, Assuân, Cairo and at the tails of the Rosetta and
Damietta branches during the time of low supply we can only admire the
perspicacity of the greatest hydraulic engineer of the last century.


26. =Nile water.=--For the following information I am principally
indebted to M. J. Barois’ “Les irrigations en Egypte” just published,
and to an article by Mr G. P. Foaden in the Journal of the Khedivial
Agricultural Society for January 1903. The colour of Nile water is
generally a pale yellow, but in June, when the first indications of the
coming flood are given by a continuous gentle rise of the river from its
minimum gauge, the water changes to green and remains so for two or
three weeks. This green water has a very disagreeable taste and odour,
and is especially objectionable when the Nile has been very low and the
rise is a slow one. In June 1900 it was extraordinarily bad, and the
river water was so poor in oxygen that standing on Kasr-el-Nil bridge at
Cairo one could see the surface of the water covered with fish which
apparently could only live near the surface. In the deep reaches near
Kalabsha in Nubia, the fish died in myriads. This green water is
attributed by some to the immense amount of vegetable matter brought
down by the White Nile from the Sudd region. Some say that it comes
principally with the first rise of the Sobat river. But the generally
accepted theory to-day is that the green water is the result of
vegetable growths from germs is the water itself, and that wherever or
whenever the current becomes exceedingly slack they multiply greatly.
Upstream of the Assuân dam in June 1903 the water was extraordinarily
green and exceedingly objectionable. As it was shot out of the upper
sluices of the dam and broken up into spray on the downstream side of
the dam it became so purified that I found it difficult to understand
that the water flowing past Elephantine Island was what I had seen at
Shellal. The green water is followed by the red water of the Nile flood,
which has always thoroughly established itself at Cairo by the 1st of
August. This red water comes from the scourings of the volcanic plateau
of Abyssinia by the Blue Nile and the Atbara. Rich in mud and rich in
manures, this red water is the creator of Egypt. Egypt is nothing more
than the deposit left by the Nile in flood. The water is most heavily
charged with detritus in August, less in September, and still less in
October.

Many analyses have been made of Nile water. Following M. Barois, I place
side by side the analysis of Dr. Letheby of 1874⁄75 and Dr. Mackenzie
of 1896/97/98. The year 1874 was an extraordinarily high flood.

  =========+==============================
   Month.  | PARTS IN 100,000 OF WATER
           +----------+--------+----------
           |    Dr.   |   Dr.  |The Mean
           |Mackenzie.|Letheby.|of the two
  ---------+----------+--------+----------
  January  |   31·0   |  16·7  |   27·4
  February |   25·3   |  12·6  |   22·1
  March    |   12·7   |   5·3  |   10·9
  April    |   15·8   |   6·6  |   13·5
  May      |   14·7   |   4·8  |   12·2
  June     |   14·1   |   6·9  |   12·3
  July     |   13·9   |  17·8  |   14·8
  August   |  159·0   | 149·2  |  156·6
  September|  156·1   |  53·3  |  130·4
  October  |  110·0   |  37·8  |   92·8
  November |   70·8   |  34·4  |   61·7
  December |   47·0   |  28·9  |   42·4
  ---------+----------+--------+----------
    Mean   |   56·0   |  31·3  |   49·8
  =========+==========+========+==========

From this last column M. Barois concludes that in high floods
100,000,000 tons of solid matter pass Assuân, and 88,000,000 in mean
floods. It is unfortunate that we have no analyses of low floods like
1877, 88, 99, 1902 and 1904 which were extraordinarily muddy. The water
had little sand but much mud. The sand is scoured out of the bed of the
river itself in high floods.

After Dr. Letheby the composition of Nile deposit is as follows:--

  =========================+=========+==============
                           |In flood.|In low supply.
                           +---------+--------------
  Organic matter           |  15·02  |    10·37
  Phosphoric acid          |   1·78  |      ·57
  Lime                     |   2·06  |     3·18
  Magnesia                 |   1·12  |      ·99
  Potash                   |   1·82  |     1·06
  Soda                     |    ·91  |      ·62
  Alumina and oxide of iron|  20·92  |    23·55
  Silica                   |  55·09  |    58·22
  Carbonic acid and loss   |   1·28  |     1·44
  -------------------------+---------+--------------
         Total             | 100·00  |   100·00
  =========================+=========+==============

Comparative analyses of subsoil water in Egypt and Nile water in time of
low supply are given below.

  =================================+========================
                                   |    PARTS IN 100,000
      Dissolved matter.            +-----------+------------
                                   |Well water.|Summer water
                                   |           |  in Nile.
  ---------------------------------+-----------+------------
  Lime                             |   16·56   |   4·24
  Magnesia                         |    4·53   |   1·00
  Soda                             |    8·20   |   6·20
  Potash                           |     ·37   |   1·44
  Chlorine                         |   13·60   |    ·67
  Sulphuric acid                   |    5·93   |   2·16
  Nitric acid                      |     ·17   |   --Traces
  Silica, alumina and oxide of iron|    1·80   |    ·97
  Organic Matters                  |     ·60   |   1·75
  Carbonic oxide and loss          |   12·26   |   4·03
  ---------------------------------+-----------+------------
                                   |   64·02   |  22·46
  =================================+===========+============

It must be remembered that Nile water in the time of low supply consists
in a very appreciable part of subsoil water which has filtered into the
Nile.

Mr. Foaden states that, speaking in round numbers, we may say that Nile
deposit in flood contains

  Nitrogen           ·1 per cent
  Phosphoric acid    ·2    „
  Potash             ·6    „

He values the manure deposited by the Nile annually in a well irrigated
basin at £·75. He concludes that Nile water in flood is rich in potash,
fairly rich in phosphoric acid and poor in nitrogen.


27. =The soil of the Nile valley.=--According to numerous analyses made
of Egyptian soil in 1872 by MM. Payen, Champion and Gastinel, the soil
of Egypt consists of

  Silica              45         per cent
  Argile              53            „
  Magnesia             ·2 to 1·6    „
  Lime                1·3 to 4·9    „
  Nitrogen            ·03 to ·10    „
  Phosphoric acid     ·03 to ·32    „

Some stiff soils contain 84 per cent argile and some light soils contain
68 per cent sand. As one approaches the Mediterranean the quantity of
chloride of soda increases and runs from a fraction to 4, 5, and even 10
per cent.

From the means of ten samples of soil from Kena Mudirieh analysed for me
in May by Mr. Frank Hughes of the Agricultural Society we gather that
the constituents of the soil are as follows:--

  =====================================+======+======+=======
  Ingredients.                         |Max %.|Min %.|Mean %.
  -------------------------------------+------+------+-------
  Silica etc., insoluble in strong acid|66    |53    |60
  Total Lime                           | 3·80 | 2·50 | 3·34
  Total Potash                         | 1·19 |  ·46 |  ·74
  Total Potash available               |  ·072|  ·020|  ·042
  Total Phosphoric Acid                |  ·49 |  ·20 |  ·35
  Total Phosphoric available           |  ·090|  ·029|  ·066
  Carbonic Acid = Chalk                | 3·52 | 1·79 | 2·69
  Nitrogen                             |  ·106|  ·056|  ·084
  =====================================+======+======+======

We have here a general sufficiency of phosphoric acid, plenty of potash
and lime, and a low proportion of nitrogen.

The salts of the soil, when in excess, are chlorides and sulphates of
soda: the carbonates are present in very small quantities indeed.

The following selection from a paper by Mr. Lang Anderson in the
December 1903 number of the Journal of the Khedivial Agricultural
Society is interesting.

“Voelcker’s analyses of the two samples of soil taken from the drained
bed of what was Lake Edku near Alexandria give the following results:--

  ============================+=======+=======
                              | No. 1.| No. 2.
  ----------------------------+-------+-------
  Oxide of iron               | 11·69 | 11·04
  Iron pyrites                |  0·08 |  0·11
  Aluminium                   |  6·36 | 10·88
  Lime                        |  2·08 |  7·73
  Magnesia                    |  1·79 |  0·93
  Soda                        |  0·79 |   ..
  Sodium chloride             |  8·11 |  8·56
  Potash                      |  0·65 |  1·23
  Sulphuric acid              |  2·23 |  2·56
  Carbonic acid               |  0·19 |  4·75
  Phosphoric acid             |  0·16 |  0·19
  Insoluble silicates and sand| 62·23 | 45·81
  Organic matter              |  3·64 |  6·21
                              |       |
                       Total  |100·00 |100·00
  ----------------------------+-------+-------
  Containing nitrogene        |  0·035|  0·070
      „      ammonia          |  0·042|  0·079”
  ============================+=======+=======


28. =Basin irrigation.=--Considering the times of flood and low supply,
the climate of Egypt, the turbidity of the Nile flood, and the deltaic
formation of the Nile valley, no better system than basin irrigation as
practiced in Egypt could possibly have been devised. If the flood had
come in April and May and been followed by a burning summer, or if the
actual autumn floods had been followed by the frozen winters of Europe
or the warm winters of the Sudan, basin irrigation would have been a
failure or a very moderate success; but, given the Egyptian climate,
basin irrigation has stood without a rival for 7000 years.

Basin irrigation, as it has been practised in Egypt for thousands of
years, is the most efficacious method of utilising existing means of
irrigation which the world has witnessed. It can be started by the
sparsest of populations. It will support in wealth a multitude of
people. King Menes made his first dyke when the Egyptian nation was in
its infancy. Egypt, in Roman times, supported a population twice as
dense as that of to-day. The direct labour of cultivation is reduced to
an absolute minimum.

Shakespeare’s genius has crystallised the system for all time:--

        “They take the flow o’ the Nile
    By certain scales in the Pyramid; they know,
    By the height, the lowness, or the mean, if dearth
    Or foizon follow: the higher Nilus swells,
    The more it promises: as it ebbs, the seedsman
    Upon the slime and ooze scatters his grain,
    And shortly comes to harvest.”

If we cast back our view to the dawn of Egyptian history, we can picture
the Nile Valley as consisting of arid plains, sand dunes, and marshy
jungles, with reclaimed enclosures on all the highest lands. Every eight
or ten years the valley was swept by a mighty inundation. The seeds of
future success lay in the resolve of King Menes’ engineers to confine
their attention to one bank of the river alone. It was the left bank of
the river which history tells us was first reclaimed. A longitudinal
dyke was run parallel to the stream, and cross dykes tied it to the
Lybian hills. Into these basins or compartments the turbid waters of the
flood were led by natural water-courses and artificial canals and
allowed to deposit their rich mud and thoroughly saturate the soil; and
meantime the whole of the right bank and the trough of the river itself
were allowed to be swept by the floods. It must have been on this wild
eastern bank that were conducted all the hippopotamus hunts which are
crowded on the wall pictures of buildings of the early dynasties. In all
probability, the first six dynasties contented themselves with
developing the left bank of the Nile. As, however, the population
increased, and with it the demand for new lands, it became necessary to
reclaim the right bank of the river as well. The task now was doubly
difficult, as the river had to be confined to its own trough. This
masterful feat was performed by the great Pharaohs of the XIIth Dynasty,
the Amenemhats and the Usartsens, who, under the name of Sesostris,
usurped the place of Menes in the imagination of the ancient world. They
were too well advised to content themselves with repeating on the right
bank what Menes had done on the left. By suddenly confining the river
they would have exposed the low-lying lands of Memphis and Lower Egypt
to disastrous inundations. To obviate this, they widened and deepened
the natural channel which led to the Fayoum depression in the Lybian
hills, and converted it into a powerful escape to carry off the excess
waters of high floods; and so successful were they in their undertakings
that the conversion of the Fayoum depression into Lake Mœris was long
considered by the ancient world as one of its greatest wonders. They led
the flood into the depression when it was dangerously high, and provided
for its return to the river when the inundation had come to an end. By
this means, they insured the lake against being at a high level during a
period of flood. The gigantic dykes of entry and exit were only cut in
times of emergency, and were reconstructed again at an expense of labour
which even an Egyptian Pharaoh considered excessive. To understand how
capable Lake Mœris was to control the floods, and turn a dangerous into
a beneficial inundation, I should recommend a study of Sir Hanbury
Brown’s “Fayoum and Lake Mœris.” As years rolled on the Nile widened and
deepened its own trough, to which it was now confined; and, eventually,
the time came when Lake Mœris could be dispensed with without danger. It
was gradually reclaimed and converted into the Fayoum with its 350,000
acres of cultivated land.

Basin irrigation holds the flood waters for some 45 days per annum over
the whole of the valley. The water is in places 3 metres deep, and in
others only 30 centimetres deep, while the average depth is about 1
metre. Now the retention of this water over the land for a period of six
weeks permits of the thorough saturation of the subsoil in places where
the subsoil is of proper consistency; and this water can be drawn on, in
winter and summer, for maturing certain crops and growing others. It was
where the subsoil gave a plentiful supply of water, and permitted of
intense cultivation throughout the year, that we find all the ancient
capitals of Egypt. Abydos has the finest subsoil water in the Nile
Valley; Memphis has an excellent supply; while Thebes has the only good
subsoil water on the whole of the right bank. Good subsoil water was to
the ancient Egyptian world what the presence of a rich gold mine is to
one of our new colonies.

[Illustration: PLAN XIV

THE NORTH SOHAG SYSTEM OF BASINS

_Scale 1 : 200,000_

Lith. Sur. Dep. Cairo.]

Subsoil water supplies the link between basin and perennial irrigation.
It explains the reason why modern Egypt is not satisfied with the
irrigation which has come down from the remotest antiquity, but is
desirous of conferring on the length and breadth of the Nile Valley
those advantages which gave Abydos, Memphis, and Thebes their
pre-eminence in the past. Any country which possesses rivers and streams
whose waters are in flood for six weeks per annum at a suitable season
of the year can betake itself to basin irrigation with more or less
profit. The science of dams, weirs, and regulators has received such
development during recent years that there can be no problem so
difficult that it cannot be solved by experience and originality. Basin
irrigation allows of the thorough development of countries whose streams
have short and turbid floods which precede a fairly cool season; whether
such irrigation be the stately irrigation of the Nile Valley, perfected
by the science and experience of 7,000 years; or the less perfect, but
still highly developed and river-fed tank systems of Madras; or the
primitive, but effective basins of Bundelkund, where the impounded water
irrigates the crops on the down-stream sides of the basins for one
season, and then allows of the basins themselves being dried and
cultivated in the next.

The Nile in high flood rises 10 metres above its bed, in a mean flood 9
metres and in a poor flood 7¹⁄₂ metres. The beds of the main basin
canals are about 4¹⁄₂ metres, and the cultivated land at the river’s
edge about 9 metres above the river-bed. The basins have an average area
of 7,000 acres. Where the valley is narrow, they average 2,000 acres
each, and where it is wide 20,000 acres; while some of the tail basins
are 40,000 acres in extent. Each canal has about seven or eight basins
depending on it, of which the last is always the largest. There are
masonry regulators at the canal heads, at each crossing of the cross
banks, and at the tail escapes into the river. In the more perfect
basins the canals and escapes syphon under one another and overlap and
supply each other’s deficiencies, so as to meet the requirements of
every kind of flood which Egypt can experience. Colonel Ross’s work on
the basin irrigation of Egypt is a monument of patient observation and a
storehouse of information. Some of the canals like the Sohagia on Plate
XIV are veritable rivers, discharging 450 cubic metres per second; but a
good average canal discharges 30 cubic metres per second. The largest
canal has a width of 75 metres, while the average width is 9 metres.
Good basin canals discharge in an average year one cubic metre per
second per 700 acres. Forty-five days suffice for a perfect irrigation.
The cost of providing basin irrigation in Egypt for basins of 10,000
acres may be taken at £3 per acre thus made up:--Banks, £1·50.; canals,
£·75.; masonry works, £·50.; and bank protection, £·25. If the basins
are under 5,000 acres, the cost will be nearly double this. The annual
cost of maintenance is £·10 per acre; while the lands themselves are
rented at £3 per acre. In well irrigated basins no manures are needed,
and alternate crops of cereals and legumins have been reaped for
centuries without the land having been exhausted in any way whatever.
Where the subsoil water is good and double cropping resorted to, then
manures have to be applied.


29. =Perennial Irrigation.=--The foundation-stone of the conversion of
the whole of Egypt from basin to perennial irrigation was laid by
Mehemet Ali in 1833, when he began the construction of the Barrages
across the Nile branches north of Cairo. These weirs were intended to
raise the summer level of the Nile by 3 metres. As the ordinary summer
level of the Nile was 1.50 metres above its bed, the weirs were expected
to raise it 4.50 metres above the Nile bed. The old basin canals had to
be considerably deepened to take in the summer supplies; while in other
parts new perennial canals were dug. Perennial irrigation requires
canals capable of discharging 1 cubic metre per second per 3500 acres,
as against 700 acres for basin irrigation. Some of the perennial canals
are very capacious. The two largest discharge 700 and 450 cubic metres
per second respectively. There are no artificial canals in the world
like them. All the canals are liberally provided with regulators and
locks. The energies of the Irrigation Department during the last ten
years have been chiefly directed to the provision of sufficient drains
to meet that over-saturation of the soil, which all but the best
regulated perennial irrigation invariably entails. After many years’
experience in India and Egypt, we are convinced that the construction of
drains and escapes should precede, and not follow the canals. It seems
fatuous for engineers to be always over-saturating and half-ruining tens
of thousands of acres of low-lying lands, during the improvement of
hundreds of thousands of acres of high-lying lands, when it would be
perfectly easy, with a little foresight, to secure all the advantages
without piling up disadvantages. The drains have generally one-third the
capacity of the canals. Dry crops require 1 cubic metre per second per
3500 acres; and rice requires the same per 2000 acres. The drains in
dry-cropped lands provide for 1 cubic metre per second per 10,000 acres,
and in rice lands 1 cubic metre per second per 6000 acres.

[Illustration: PLATE XIX.

PERENNIAL CANAL SYSTEM OF LOWER EGYPT

Lith. Sur. Dep. Cairo.]

While basin irrigation is followed by the winter crops of wheat, beans,
clover, barley, flax, lentils, vetches and onions, perennial irrigation
allows of all the above winter crops and in addition the summer crops of
cotton, sugar-cane, oilseeds, gardens and orchards. It will readily be
understood that all this double cropping necessitates a very free use of
manures.

It would be a healthy innovation indeed, if the provision of suitable
manures were to be considered as an essential part of a project for
providing perennial irrigation. The day is not far distant, I believe,
when governments which provide irrigation works will also provide
manures, and sell the water and the manures together, one being as
essential as the other; I know well, from observation, that a
well-manured field needs only half the water that a poorly manured field
does; and in years of drought and scarcity manures almost take the place
of irrigation. Why should there not be a manure-rate as well as a
water-rate? Here in Egypt, the numerous ruins of old-world cities have
hitherto provided manure for a great part of the perennially irrigated
lands; but these are being fast worked out, and other sources must be
sought for. Farm-yard manure will never suffice for the intense
cultivation in this country. In connection with this subject, I can
recommend the study of a remarkably able paper on “Nile Cultivation and
Nitrates,” read by Mr. J. B. Fuller, C.I.E., before the Agricultural
Society of England, and embodied in the 3rd Series, Vol. VII., Part 4,
1896. Egypt possesses, in the vicinity of Luxor, natural beds of
nitrates of unlimited extent, which come down to the river’s edge. These
nitrate beds have been used from time immemorial, but were brought to
the notice of the general public by Mr. Floyer. They contain only about
6 per cent. of pure nitrates, but as they are on the edge of the Nile,
in a perfectly cloudless and very dry country, it might be possible,
with the aid of the plentiful supply of water always at hand to
profitably extract pure nitrates. The demand for nitrates is without
limit in the Nile Valley, as Nile water, though rich in everything else,
is exceedingly poor in nitrates.

The perennial canals and collateral works have cost £4.50 per acre, and
the maintenance charges are £·10 per acre. The perennially irrigated
lands are let at £5 to £8 per acre per annum as against £3 to £5 for the
basins lands.


30. =Flood protection in Egypt.=--The Nile during high floods is
considerably above the level of the country, which is protected by
embankments stretching from Assouân to the sea. In Upper Egypt, a very
high flood is one metre above the country; in Middle Egypt it is 2
metres, and the same on the Rosetta branch of the Nile. On the Damietta
branch it is 3·50 metres in places.

In parts of Upper Egypt, but nearly everywhere in Lower Egypt, the Nile
on curves is protected by stone spurs. These spurs contain each from
4,000 to 250 cubic metres. They are very effective where the Nile bank
has been well thrown back below them to a distance of some 50 metres on
a length of at least 100 metres. This allows the waters of the flood to
swirl harmlessly in whirlpools below the spurs while the banks are far
removed from their action.

When we first came to Egypt, we found that the policy was to spread the
flood into as many channels as possible and protect the whole of them
with tens of thousands of corvée, in addition to the corvée on the Nile
banks. We changed that and concentrated our energies on the Rosetta and
Damietta branches.

In 1861, 1863, 1866, 1869, 1874, and 1878 the Damietta branch was badly
breached, There has been only one serious breach on the Rosetta branch,
and that was in 1863. The great breach of 1878 on the Damietta branch
was attended with serious loss of life; but far more serious was the
breach of 1863 on the Rosetta branch not far from its head. The whole
western half of the Delta proper was swept by the river, and as the
canals there have not got good high banks, the people had no place of
shelter to flee to and were drowned in very great numbers. The same
thing would happen again if a breach were to occur now, only the damage
would be far more serious. The country is covered with villas and rich
plantations and the low lands to the very edges of Lake Borrilos are
being reclaimed and inhabited. The loss of life which would occur
nowadays would be truly appalling. A breach anywhere within 100
kilometres of the Barrage on the east bank of the Rosetta branch or the
west bank of the Damietta branch during a very high flood would be a
national disaster.

The terror reigning over the whole country during a very high flood is
very striking. The Nile banks are covered with booths at intervals of 50
metres. Each booth has two watchmen, and lamps are kept burning all
night. Every dangerous spot has a gang of 50 or 100 special men. The
Nile is covered with steamers and boats carrying sacks, stakes, and
stone; while the banks along nearly their entire length are protected by
stakes supporting cotton and Indian corn stalks, keeping the waves off
the loose earth of the banks. In a settlement of a culvert in the Nile
bank north of Mansourah in 1887 I witnessed a scene which must have once
been more common than it is to-day. The news that the bank had breached
spread fast through the village. The villagers rushed out on to the
banks with their children, their cattle, and everything they possessed.
The confusion was indescribable. A narrow bank covered with buffaloes,
children, poultry, and household furniture. The women assembled round
the local saint’s tomb, beating their breasts, kissing the tomb, and
uttering loud cries, and every five minutes a gang of men running into
the crowd and carrying off the first thing they could lay hands on
wherewith to close the breach. The fellaheen meanwhile, in a steady,
business-like manner, plunged into the breach, stood shoulder to
shoulder across the escaping water, and with the aid of torn-off doors
and windows and Indian corn stalks, closed the breach. They were only
just in time. This is the way the fellaheen faced a breach. And this is
how the old Governors of Egypt faced them. During the flood of 1887 I
complimented an official on the Nile bank, whose activity was quite
disproportionate to his apparent age. He told me that he was a
comparatively young man, but he had had charge of the Nile bank at Mit
Badr when the great breach occurred in 1878, and that Ismail Pasha had
telegraphed orders to throw him and the engineer into the breach. He was
given 12 hours’ grace by the local chief, and during that interval his
hair had become white; subsequently he was pardoned. These were the
senseless orders which used to petrify officials into stupidity.

The following estimate was made by me of the cost of protecting the
Delta proper between the two branches of the Nile during the high flood
of 1887:--

Cost of protection for 432 kilometres of bank or 1,200,000 acres of
cultivation:--

                  {Sand bags    60,000 @ £ ·03             = £  1,800
  _Materials_     {Stone         5,000 @ „ ·50             = „  2,500
  _paid for_      {Stakes       55,000 @ „ ·06             = „  3,300
                                                             --------
                                                             £  7,600
                                                             ========

                  {Camel loads of stalk for 42 kilometres,
  _Materials_     {  14,000  @ £ ·15                       = £  2,100
  _not paid for_  {                                          --------
                                      Total materials        £  9,700
                                                             ========

                   15 engineers @ £80                      = £  1,200
                   Unpaid corvee, 1,374,079 men @ £ ·03    = „ 41,222
                                                             ========
                                            Total labour     £ 42,422
                                                             ========
                              Total materials and labour     £ 52,122

This works out to £120 per kilometre of bank, or £·045 per acre of land
protected. It is a very cheap insurance.




CHAPTER IV.

Projects.


31. =Projects.=--No account of the Nile in 1904 would be complete
without an enumeration and slight examination of the projects before the
public for the provision of sufficient water to the Nile in times of low
supply to insure the perennial irrigation of the whole of Egypt; to
utilise these perennial waters by converting basin tracts into
perennially irrigated ones; to protect the country from the dangers
accompanying high floods; and to permit of the reclamation of the low
salted lands of Lower Egypt which border the Mediterranean sea.

Egypt has a total irrigable area of 6¹⁄₄ millions acres. Of this area,
¹⁄₄ of a million acres, which are to-day inundated in flood and lie
along the edge of the deserts, must continue to be inundated in flood
for all time, to prevent the sands of the desert from spreading over the
Nile Valley. Their value is £5,000,000. Four million acres are
perennially irrigated. They have a mean value of £55 per acre, and have
a total value of £220,000,000. Of the remaining two million acres,
two-thirds are irrigated only in flood and one-third is not irrigated at
all. These 2 million acres have a mean value of £25 per acre, and are
worth £50,000,000. The land of Egypt may be considered as worth
£275,000,000 to-day. If it were possible to perennially irrigate the 2
million acres which are without such irrigation, their value would be
increased by £30 per acre, or by £60,000,000.

The problem before us is how to provide perennial irrigation to these 2
million acres and so add £60,000,000 to the wealth of the country.

It has been calculated that each milliard of cubic metres of water
stored in reservoirs situated in Egypt itself is sufficient to insure
the conversion of half a million acres from flood to perennial
irrigation. Egypt therefore requires reservoirs capable of storing 4
milliards of cubic metres of water.

In Mehemet Ali’s time, the great preoccupation of the Government was the
pressing on of the cultivation of cotton, and as this crop needed
perennial irrigation, the securing of an abundant supply of water all
the year round was the problem of the day.

The fame of the ancient Lake Mœris had made a profound impression on the
mind of Mehemet Ali, and he urged on his chief engineer the necessity of
undertaking similar works. Linant Pasha first set himself to discover
the site of the ancient lake, and then estimated roughly the cost of
reconstructing it, but considered the cost prohibitive. He recommended
Silsila as a suitable site for a weir and a canal head. The failure of
the Barrage discouraged the Government from undertaking new works and
the question dropped. In 1880 Count de la Motte proposed a dam at
Silsila and a reservoir to the south of it. He also proposed putting a
capacious depression to the east of Kalabsha in communication with the
Nile by the aid of a dam at Kalabsha.

About two years later Mr. Cope Whitehouse suggested utilising the Wadi
Rayan depression as a reservoir. This depression had been already
mentioned by Linant Pasha in his book and located by him on his
hydrological map. Financial difficulties prevented Sir Colin
Scott-Moncrieff from immediately considering the question of reservoirs.
The success of the Barrage repairs in 1887 however gave new life to the
question of reservoirs and Sir Colin Scott-Moncrieff deputed Col.
Western to give scope to the suggestion made by Mr. Cope Whitehouse, to
make plans of the Wady Rayan and the deserts between it and the Nile, to
find out the capacity of the reservoir, and see if it could be utilised.
Col. Western’s report, plans and estimates were printed by the Egyptian
Government in 1888. At the same time I was deputed to examine the other
projects of Count de la Motte. In 1889 and 1891 I reported unfavourably
on them, because I could find no depression near Kalabsha to put in
communication with the Nile, and could find no rock at Silsila on which
to build a dam. The Bergat Takham pan was the only depression near
Kalabsha which could have been used as a reservoir and it was over 100
metres above the level of the Nile flood; while both in the Silsila pass
and the Silsila gate I bored for rock and was everywhere still in sand
10 metres below the level at which the existence of rock was assumed by
the Count’s engineers. On my report reaching Cairo, M. Prompt proposed
using the trough of the Nile itself at Kalabsha as a reservoir in place
of the depression which did not exist. Col. Western left the country in
1890 and I became Director General of Reservoir Studies. M. Prompt had
supposed that rock could be met with at Kalabsha at a depth of 4 metres
below low-water level. I could not find it at a depth of 26 metres.
After sounding and boring at every possible site on the Nile and
surveying, boring, and levelling in the desert between Wadi Halfa and
the Fayoum, I submitted my report in 1894, proposing an open dam at
Assouan of a type which I trusted would meet the requirements of a Nile
reservoir dam. Sir William Garstin approved of the site and the design,
and the dam was built between 1898 and 1902 with Mr. Maurice Fitzmaurice
C.M.G, as resident engineer.

The Assouan Reservoir at its present level contains one milliard of
cubic metres of water which will suffice for the conversion of half a
million acres to perennial irrigation, adding £15,000,000 to the wealth
of the country. But though the dam was only completed at the end of
1902, already the whole of the water has been devoted to special tracts,
and the Government is reluctantly compelled to refuse all applications
for water.


32. =The raising of the Assuân dam.=--Egypt already possesses the germ
of all the storage works she needs. Six years ago a few far-seeing men
saw clearly what all of us understand to-day; but among the few, no man
had greater faith in the future of the country than Sir Ernest Cassel.
The Assouân Reservoir project had been lying buried for four years in
official pigeon holes, when in 1898 Sir Ernest came forward with the
funds, and with Sir John Aird & Co., as contractors, and Sir Benjamin
Baker as Consulting Engineer, undertook to complete the Assouân dam and
the Assiout weir by December 1903. The Egyptian Government, advised by
Sir William Garstin, accepted his offer, and received the completed
works by December 1902.

The Assouân dam is a granite structure 2,000 metres long which crosses
the head of the Assouân cataract of the Nile in one continuous straight
line. The dam is pierced by 140 under sluices of 7 metres by 2 metres
for passing floods, and by 40 upper sluices of 3¹⁄₂ metres by 2 metres
for passing the high level water of the reservoir. The sluices are
regulated by “Stoney” gates worked by winches at the roadway level.

While the red, muddy waters of the Nile flood are pouring down the
river, the whole of the sluices are open and the river discharges itself
through them without parting with its silt. This is the real object of
the sluices, for if the dam were solid and the river forced to flow over
the top, the reservoir would soon be filled with deposit and
obliterated, while Egypt, deprived of this rich mud, would be
considerably the poorer. This is the great feature of the dam. While the
dam holds together, the reservoir will be free of silt.

When the turbid flood has passed and the comparatively clear winter
supply of the river has begun to arrive, the sluices are gradually
closed and the reservoir filled. Beginning about the 1st December, the
reservoir is filled in 100 days. It will ordinarily be full on the 1st
March. No additional water is needed for irrigation between March 1st
and May 1st as the river naturally has enough for the requirements of
the area at present under crop at this season. As the area under
perennial irrigation will be gradually increased, the demand for water
for the new lands will begin about the 1st of April. The demand
increases through May and June, and the reservoir will then be aiding
the river with its supplement. If the flood is very late, water may be
required from the reservoir till the 10th July; if the flood is early no
water will be needed after the 20th of June, as in 1903, the first year
of the reservoir. The earlier the flood the more effective the
reservoir. By the time the flood has begun to get turbid, the under and
upper sluices will all be open and the muddy waters of the Nile will
sweep through the dam without impediment.

The dam has worked for two years and given satisfaction. When the Nile
was at its lowest in May 1903, the natural discharge of the river,
supplemented by all the subsoil infiltration water which enters the
river between Assouân and the sea, was 400 cubic metres per second. The
reservoir was adding 200 cubic metres per second to the supply, raising
the total supply available for irrigation to 600 cubic metres per
second. The reservoir was supplying one-third of the water which was
being utilized in Egypt. This water will suffice for an increase to the
perennially irrigated area of ¹⁄₂ million acres.

At the time of designing the dam it was intended that it should be of
such a section that it could be raised 6 metres in height and hold up
another milliard of cubic metres of water. Such an operation, if
performed to-day, would mean: the whole length of dam being raised 6
metres, the winches working the sluice gates being raised 6 metres and
provided with new wire ropes; and new copings being given to the
parapets. It would necessitate two more locks and three more lock gates,
and nothing else. The expenditure incurred would be about £500,000.


33. =The Wady Rayan Reservoir Project.=--When the Assouân dam will have
been raised, we shall be standing on the threshold of what it will be
able to do. The projected Wady Rayan reservoir, or the modern Lake
Mœris, will be well able to supply the two remaining milliards of cubic
metres of water when working in conjunction with the Assuân Reservoir.
The great weakness of this projected lake has lain in the fact that _by
itself_ it could give a plentiful discharge in April and May, less in
June, and very little in July, and it was for this reason that in my
report of 1894 to the Egyptian Government I had reluctantly to recommend
that it be not carried out. But when the Assouân reservoir is capable of
supplying two milliards of cubic metres of water it will be possible to
utilise the Mœris Lake to its utmost capacity. The Assouan Reservoir,
being high above the level of the Nile can give its supply at the
beginning or end of the summer; it can give it slowly or with a rush;
while the projected Lake Mœris, being directly in communication with the
Nile, and only slightly above low Nile level, its discharge would depend
entirely on the difference of level between it and the Nile, and
consequently as the summer advanced its level would gradually fall and
the lake would not be able to give at the end of the summer a quarter of
the discharge it could give at the beginning.

[Illustration: PLATE XV

PROPOSED WADI RAYAN RESERVOIR

SHOWING THE FAYOUM

  _All R. L.^{s} in metres, above or below mean sea._
                              +        -

_Desert._

_Scale 1 : 500,000_

Lith. Sur. Dep. Cairo.]

But let us imagine that the reservoir and the lake are both completed
and full of water, and that it is the first of April. Lake Mœris will be
opened on to the Nile and give all the water needed in that month, while
the Assouan Reservoir will be maintained at its full level. In May, Lake
Mœris will give nearly the whole supply and the reservoir will give a
little. In June the lake will give little and the reservoir much; while
in July the lake will give practically nothing and the reservoir the
whole supply. Working together in this harmonious manner, the reservoir
and the lake, which are the true complements of each other, will easily
provide the whole of the water needed for Egypt.

The Wady Rayan is a depression in the deserts to the south of the Fayoum
and separated from the Fayoum by a limestone ridge. In 1888 Col. Western
recommended it very strongly as a reservoir. In this he was supported by
Col. Ross, the first Inspector General of irrigation. On Col. Western’s
leaving Egypt, the study was entrusted to me, and Messrs. Hewat and
Clifton deputed to make a final project. The Wady Rayan project, with
its plans and estimates, was published by the Egyptian Government in
1894. As I said before, I was reluctantly compelled to reject its
adoption owing to the one radical defect already described. That defect
will have been completely removed by the completion of the Assouân
Reservoir, when it will be possible to undertake the construction of the
modern lake Mœris.

The question of Lake Mœris has interested the world for centuries. For
the ancients it was one of the world’s seven wonders. Sir Hanbury Brown,
in his book on the “Fayoum and Lake Mœris,” has collected all the
information available about the lake, and after a thorough examination
of the question has declared in favour of the Wady Rayan being converted
into a modern Lake Mœris.

Herodotus, writing about B.C. 450, was the first to describe the lake:
“Now the Labyrinth being such as I have described, the lake named that
of Mœris, causes still greater astonishment, on the bank of which the
Labyrinth was built.

“The water in the lake is not derived from local sources, for the earth
in that part is excessively dry and waterless, but it is brought in from
the Nile by a canal. It takes six months filling and six months flowing
back. During the six months of the return flow, it yields a talent of
silver every day to the treasury, and during the flow twenty minæ for
the fish.”

Strabo, writing in B. C. 20, remarks: “It has also a remarkable lake
called the Lake of Mœris, large enough to be called a sea, and
resembling the open sea in colour.

“Thus the Lake of Mœris is, from its size and depth, capable of
receiving the overflow of the Nile at its rising, and preventing the
flooding of houses and gardens; when the river falls, the lake again
discharges the water by a canal at both mouths, and it is available for
irrigation. There are regulators at both ends for controlling the inflow
and outflow.”

Diodorus Siculus, writing at the same time, says:--“King Mœris dug a
lake which is amazingly useful and incredibly large. For as the rising
of the Nile is irregular, and the fertility of the country depends on
its uniformity, he dug the lake for the reception of the superfluous
water, and he constructed a canal from the river to the lake 80 furlongs
in length and 300 feet in breadth. Through this he admitted or let out
the water as required.”

At one time there was much discussion as to what was Lake Mœris, but
since the publication of Sir Hanbury’s book there can be but one
opinion. The lake covered the whole of the modern Fayoum below the level
of the contour which is 22¹⁄₂ metres above mean sea level. The common
Nile shells are to be met in myriads at any point on this contour round
the Fayoum that one cares to look for them. The ordinary high flood
level of Kushesha basin to-day is 26¹⁄₂ metres above mean sea. In
Amenemhat’s time, which was 4,000 years ago, the level was 4 metres
lower, or at 22¹⁄₂ metres above mean sea. This was the highest possible
level the lake could have attained in his day. In the course of time the
level of the Nile valley rose by about 10 centimetres per century, but
the frequent occasions on which the canal was kept closed during poor
and low floods gradually silted up the channel and made it less
capacious. As there are no Nile shells above the contour of 22¹⁄₂ metres
above mean sea (except a few on the south side of the lake which have
evidently been blown up by the north west winds in sand drifts) it is
evident that the gradual silting up of the channel more than kept pace
with the rising level of the Nile. Eventually the silting up exceeded
the rise, and that at an accelerated rate, the canal became weaker and
weaker, and the Fayoum Province gradually occupied the site of the lake.
Lake Mœris had lasted over 2,000 years.

The connection between the Nile and the germ of the future Lake Mœris
was in existence in King Menes’s time, as I have been informed by
professor Sayce, but it was King Amenemhat, of the XIIth dynasty, who
widened and deepened the canal, cleared away the rocky barriers, and
converted the trifling lake of King Menes’s time into the mighty inland
sea which controlled the highest floods of the Nile. Those ancient
Pharaohs were giants in hydraulic engineering. They were, moreover, as
wise as they were courageous.

Sir Hanbury Brown has well described the action of the lake. It had a
surface of 2,500 square kilometres, and being drained back into the Nile
and kept at a low level it was able to take from a very high flood 20
milliards of cubic metres of water. It was quite capable of reducing a
very high flood to moderate dimensions; and if injudiciously or
maliciously opened in a low flood, it was capable of depriving Lower
Egypt of any flood irrigation at all; and in those days they had
practically no irrigation except flood irrigation.

The Wady Rayan, as already stated, is a depression in the Lybian hills
immediately south of the Fayoum. It has, at a level of about 29 metres
above the sea, a surface of 700 square kilometres, or about one quarter
the area of the ancient lake. Like the ancient lake, the lowest point of
the Wady is 41 metres below sea level. When filled with water the
greatest depth will be 70 metres. The uppermost four or five metres only
will be utilised annually, or some 3 milliards of cubic metres of water
out of a total volume of 20 milliards. Just as the great size of the
ancient lake was of inestimable value to a work whose principal use lay
in moderating high floods, so the smaller area of the modern lake will
render it far more useful as a work for feeding the low Nile. This lake,
will render no mean aid in time of dangerous floods, but, in its early
years, its main use will be the provision of water in summer. It will
supply the two milliards which are needed to convert the whole of Egypt
from basin to perennial irrigation.

In my book on “The Assuân Reservoir and Lake Mœris” I have worked out
the cost of the project and estimated it at £2,600,000.

The rates I have allowed for the excavation work are considered too low
by some critics. If the earthwork in the Nile Valley had to be excavated
within 30-day rotations as on the running canals, I should be the first
to agree; but the work will last three years and the contractors will be
able to concentrate all the spare labour of the country on the works
when demand for labour is slack, and in this way the rate of P.T. 3 per
cubic metre which I have allowed will be found to be ample. In the hill
of salted marl it will be possible to employ the American system of
excavating by the aid of water issuing from nozzles under pressure. By
this method it will be possible to do much work at P.T. 2 and P.T. 3 per
cubic metre as it is done in America. I have allowed P.T. 5 per cubic
metre. To this hydraulic pressure work the salted marls will be
specially suited, and indeed the recollection of the ease with which
Amenemhat dug his canal though this very material lasted long in the
memory of Egyptians. Some 1,600 years after the canal was excavated,
Herodotus was informed that the excavated material was thrown into the
canal and transported by the running water. A 12-inch pump on the Yusufi
canal lifting water on to the top of the hill, a number of spade men
helping the water as it coursed down the hill and leading the liquid mud
along wooden troughs into side ravines and depressions, and a steep
slope on the western half of the hill where the rock had been blasted
away would soon remove all the material required at a very low cost. I
have allowed P.T. 10 per cubic metre for the soft limestone. Here it
will be easy to work on a vertical face of some 7 metres, blast out the
rock, carry it away on four lines of railway running down hill, deposit
the rubble on the desert; and as each 7 metres depth is completed, to
begin the next 7 metres in depth in the same way.

In my 1894 Report I had anticipated difficulties with the canal running
through the salted marl. Since then I have thoroughly inspected the
ravines in the Fayoum and seen the El-Bats ravine where it cuts through
many kilometres of this very salted marl. The sides are absolutely
vertical and deposits of mud and self-sown tamarisk bushes protect the
vertical sides at places where the running water is nearly touching the
marl. Such natural protection will be far superior to the masonry lining
I proposed and far more effective. It will moreover cost nothing.

[Illustration: PL. XVI.

WADI RAYAN RESERVOIR

LONGITUDINAL SECTION OF PROPOSED CANAL

_Horizontal Scale 1 : 150.000_

_Vertical Scale 1 : 600_

LONGITUDINAL SECTION OF THE FAYOUM]

To those critics who suggest that the waters of the lake might become
salted or leak into the Fayoum I have to reply as follows: When the old
Lake Mœris, or the present Fayoum, was full of water and 63 metres
higher than the bottom of the Wady Rayan, and remained so for thousands
of years, there was no question of the waters having become salted or
having escaped into the Wady. The Wady was as dry as it is to-day and
the great inland sea was always fresh. If there had been any serious
infiltration from the ancient Lake Mœris into the Wady Rayan, there
would have resulted a lake which could not have escaped the notice of
the numerous travellers who visited the lake. No mention was ever made
of such a lake. This body of water moreover would have been inhabited by
fresh-water animals whose remains would have strewn its shores. No such
remains are to be seen to-day. If therefore the ancient Lake Mœris with
a head of 63 metres on to the Wady Rayan could not leak into the Wady,
it is not likely that the Wady Rayan reservoir with a head of from 27 to
29 metres on the Garak side of the Fayoum will leak into that part of
the area covered by the ancient lake. Any leakage into the Lake Kurun
side is never contemplated by anybody, since many kilometres of compact
limestone lie between the Wady Rayan and it, while about one or two
kilometres of the same limestone lie between the Wady Rayan and the
Garak depression.


34. =Lake Albert reservoir project and project for training the Albert
Nile and the Zeraf River.=--If we wish not only to irrigate the whole of
Egypt, but to include the Sudan in the sphere of operations we must
regulate the supply issuing from Lake Albert Nyanza and ensure its
passage through the great swamp regions. To my mind no work in the Sudd
regions will be of any substantial value unless the Albert reservoir dam
is first built. Tabulating the information collected in the gauges and
discharge tables we may state that the discharge of the Albert Nile in
cubic metres per second between the 15th January and 15th May was as
follows in:--

                                =1901=  =1902=  =1903=  =1904=
  Discharge at Gondokoro          600     600     700    1000
  Discharge above Sobat mouth     300     300     350     435

In 1861 the discharge at Gondokoro was as low as 500 cubic metres per
second. It will be seen that, in spite of the great waste, there is an
increase at the northern end of the Sudd region even under present
conditions when the discharge at the south end is increased in the
interval between the 15th January and 15th May. The water which enters
the White Nile during these months represents the summer contingent of
the White Nile to the Nile in Egypt.

Now though an increase in April at the south end of the Sudd region is
felt at the north end, no such increase is felt in September and
October, and the reason has been given in Chapters II and III.

In April the Sobat river is discharging practically nothing, and the
whole supply available in the Albert Nile can pass down the White Nile
past the Sobat mouth. In September the Sobat river may be discharging
750 to 1,000 cubic metres per second, and as the White Nile cannot
discharge the combined waters of the two rivers, the water of the Albert
Nile is headed up and accumulated in the lowlands between Lake No and
the Sobat mouth. This is greatly to the advantage of Egypt, for it is
the discharge at the head of the White Nile between January 15 and May
15 which decides the White Nile contingent to the summer supply of the
Nile in Egypt, and the greater the quantity of water above the head of
the White Nile, in the absence of a regulator or barrage at Wadelai or
Dufilé, the better the summer supply of Egypt. After the abnormally high
flood of 1878, when Gordon was up the Nile, so great was the
accumulation that the discharge at Assuân never fell below 1500 cubic
metres per second in the summer of 1879. The Barrage was not regulated
upon and yet all the Lower Egypt canals were full of water, and the
cotton crop of Egypt for that year was quite abnormal for the seventies
of the last century.

Now an expenditure of between £400,000 and £1,000,000, say £800,000,
could secure a regulator for Lake Albert at any point between the outlet
and Dufilé. Such a regulator would insure 1200 cubic metres per second
every year to the Albert Nile at Gondokoro between the 15th January and
the 15th May. With this supply insured, the training works in the Sudd
region would soon begin to affect the discharge at the north end of this
region where the White Nile begins.

The way in which this work of training should be carried out has been
admirably laid down in page 174 of Sir William Garstin’s Report. “Alter
the flood conditions of the Albert Nile (Bahr-el-Gebel) as little as
possible, let the excess flood water escape on both sides, but keep the
summer supply in its channel.” This is, to my view, the soundest
statement from an engineering point of view in the whole report.
Hitherto we have always assumed a vast expenditure for keeping the flood
supply in one channel; but with our attention devoted to the summer
channel, we should have before us all the advantages of summer training
works without any fear of inundations. The very wildness of the regions
would be in our favour. To be able to train a river in summer without
any nervousness about floods, is given to few engineers. I had never
thought that any good thing could come out of the sudd region, but
looked at from this point of view, we can, even in this inhospitable
waste of waters, confirm Shakespeare’s saying that “there is some soul
of goodness in things evil.”

The Lake Albert reservoir could easily insure 1200 cubic metres per
second every year between the 15th January and the 15th May. To pass
through the Sudd regions as much as possible of the 1200 cubic metres
per second received at Gondokoro, the following works would be
necessary:--

The first work to be done would be the removal of sudd block No. 15
which for 37 kilometres south of Hillet-el-Nuer has turned the Albert
Nile out of its course. The importance of this is strongly insisted on
by Sir William Garstin on page 55 of Appendix VI of his Report, which is
the very last thing he wrote. With this block removed, the Albert Nile
would be given a good opportunity of working out its own salvation.

The next point is one to which I attach the greatest importance. Indeed,
I look upon it as the key of the whole region. The Albert Nile enters
the south-east corner of Lake No and almost immediately afterwards
leaves its east corner. Now Lake No is the final evaporating basin of
the Bahr-el-Gazelle, probably the most unsatisfactory river in the whole
world; and it is open to doubt whether in a year of deficient rainfall
on its own catchment basin and a year of good supply down the Albert
Nile, it does not evaporate a considerable quantity of the water of the
Albert Nile. If the discharge of the Albert Nile north of Hillet Nuer
was brought to 450 cubic metres per second in April, this lake might
waste much of it. Such being the case, a cut of a maximum length of some
5 kilometres should be dredged south of the south-east corner of the
lake, and the waters of the Albert Nile separated from those of the
Gazelle. A cheap wooden lock and regulator would allow boats to pass,
and take in any water from the Gazelle river when it had it to give.
The maximum water we have to deal with is zero in summer and 40 cubic
metres per second in flood. If the Albert Nile were separated from the
Gazelle, it might be found that the waters of the Gazelle river found
their way into the Albert Nile through that mysterious and
unsatisfactory river the Lolle. Some use might even be found for it. I
have, since I wrote this, been informed by Capt. Lyons that Marno in
1881 proposed this cut round the south-east corner of Lake No. (Pet.
Mitheil, 1881, page 425 and plate 20).

The Albert Nile to-day at Hillet-el-Nuer is capable of carrying 450
cubic metres per second. North of Hillet-el-Nuer, the Albert Nile has a
mean width of 75 metres, but owing to want of training and papyrus
swamps, the discharge dwindles down to 320 cubic metres per second. The
Albert Nile has in this reach a very good section indeed and by
beginning with the west bank and dredging round corners and closing
spills by dredged earth, an improvement of section and slope, backed up
by a permanent discharge of 450 cubic metres per second at
Hillet-el-Nuer, might speedily result in this very discharge of 450
cubic metres per second being obtained south of Lake No. We are here in
such swamped land that percolation would be practically zero. There are
only 200 kilometres of channel with all its curves, or 160 kilometres of
trained channel to work at, in which 75 per cent of the work is to hand;
and we have to confine our attention to the low supply without worrying
over the flood supplies.

Now the Bahr-el-Zeraf could be made capable of carrying 150 cubic metres
per second by an improvement of the inlet at Baker’s channel and by
dredging north of Ghaba Shambe, as will be seen by examining the
measured discharges of the Bahr. With the Bahr-el-Zeraf carrying 150
cubic metres per second and the Albert Nile carrying 450 cubic metres
per second, we should have ensured 600 cubic metres per second. As time
went on, improvements in the channels would make themselves felt, as
they are even doing to-day, and we might even have 700 and 800 cubic
metres per second at the head of the White Nile below the Sobat mouth.
We must always remember that it is assumed that the lake Albert
reservoir dam has been constructed and a supply of 1,200 cubic metres
per second assured at Gondokoro from January to May. If the Sobat river
were capable of regulation downstream of the Pibor marshes, we might get
an increase from that direction as well. The possibility of a good site
for a reservoir upstream of Nasser is very great. The Nasser gauge rises
and falls so slowly that there must be very great natural accumulations
of water upstream of it, which might be improved. The question of
quality needs study.

The discharge of 435 cubic metres per second, which the rivers in their
present state, aided by the Lake Albert reservoir, could deliver into
the White Nile, would thus see itself gradually increased to 500, 550,
and 600 cubic metres per second and even more, and would enter the White
Nile past the Sobat mouth in February, March, April and May. During
these months the whole of the supply would pass down the White Nile
without throwing backwater on the rivers. Later on, when the Sobat river
came down in flood and filled up the channel of the White Nile, the
Albert Nile would have its waters reduced at the Albert regulator, and
the waters of Lake Albert would again be stored for the day when the
Sobat floods had fallen and the White Nile channel was free and ready to
take in the waters of the Albert Nile.

While I had contemplated the training of the flood waters of the Albert
Nile through the Sudd regions I had estimated the cost at £100,000 per
annum, for 25 years, or at £2,500,000. Now, however, that Sir William
Garstin has shown how we need only attend to the summer supplies, the
sum may be reduced to half the former figure or to £1,200,000, and be
more than ample. With £2,000,000 devoted to the Lake Albert reservoir
and the training works in the Sudd region, the summer supply of Egypt
and the northern Sudan would be put on a firm base.

Dr. Schweinfurth, the eminent African traveller and savant, was the
first to call the attention of the Egyptian Government to the necessity
of closing the spills from the White Nile to the north of Gondokoro, and
so beginning the training of the river. He very rightly said:--“Many
years would elapse before the desired result would be obtained by the
strengthening of the banks, but the works would be increasingly felt
every year in Egypt as the works progressed.”


35. =Flood protection for Egypt.=--In paragraph 30 it was stated that
the floods in the Delta or in Lower Egypt can rise to a height of from 2
to 3¹⁄₂ metres above the level of the country. Such floods are really
dangerous and means should be found for moderating them.

The Wady Rayan reservoir, when converted into the modern Lake Mœris and
acting as a reservoir, will have one great advantage, it will be able to
lower a high flood 30 centimetres for 50 days. This will give relief to
the Nile, a relief which will be much appreciated by the whole country
from Beni Suef to the sea, and especially by Cairo.

I have already stated that the Damietta branch is especially dangerous
and unfit to act as an escape under existing conditions. That branch
could be regulated on at its head and treated like a canal. Thanks to
Sir Hanbury Brown’s initiative the Barrages can be regulated on in flood
as well as in summer, and by lowering the supply in the Damietta branch
and turning the surplus down the Rosetta branch, the latter would become
the flood escape of the Nile. It might be trained as Mr. Eads suggested
that rivers should be treated.

Mr. Eads’ argument is very clear. He insists that rivers eat away their
banks in places, not owing to the direct action of the water but by the
alterations in the velocity of the current. When the river water is
charged with sediment to its full carrying capacity it cannot take up
more unless the rate of current be increased. If the channel be nearly
uniform the river water cannot eat away any of its banks. If, however,
the channel is varying, the silt deposits in the wide sections, and the
water, free of some of its sediment, is ready to eat more. It is this
alternate dropping silt and eating away of earth which does the harm. To
treat the Rosetta branch according to Mr. Eads it would be necessary to
fix the top width to be worked to, at say 550 metres. The river could be
brought to this uniform top width by building light inexpensive
permeable spurs on the sandy shoals. The land between the spurs would
become cultivated and such river training would pay the Government,
which taxes all cultivated land; it would even pay handsomely for any
company to undertake the work once the rule about foreshores was
understood. The Government would, however, always succeed; when it could
not sell, it could always tax. Such training would permanently lower the
flood.

In addition to the above it would be necessary to complete the system of
spurs begun in 1884, and to throw back the banks as already recommended.
It has been estimated that the completion of this work would cost
£900,000 for spurs and banks, while the training works would pay for
themselves in addition to greatly improving the channel and lowering the
level of the flood.

It may be humiliating to make the confession, but from B.C. 2,200 to the
Arab invasion of Egypt in A.D. 640, while Lake Mœris performed its
allotted task and the Nile possessed training works such as those we
can see to-day in Nubia, Egypt was better protected from inundation, and
the Nile better trained, than it is to-day. And yet we have many
advantages which no Pharaoh possessed. By the aid of telegraphy we have
knowledge of a coming flood a full fifteen days before it arrives in the
Delta; the Khartoum gauge allows us to anticipate its very height.
Meteorology is aiding us still further. In a paper I read at the Chicago
International Exhibition I stated that years of heavy rainfall in India
are years of high flood in Egypt, while years of poor rainfall in India
are years of low flood in Egypt. Sir John Eliot, the Director General of
the Meteorological Department of India, corrected this statement. He
said that though this was not true of the Bengal monsoon, it was true of
the Bombay monsoon. Years of heavy rainfall in Gujerat and Bombay are
years of high flood on the Nile, and vice versà. As the rain falls in
Bombay a month earlier than the Nile flood reaches Cairo, we have
information of a high flood a month before it arrives, if we receive
telegraphic information from Bombay.


36. =Complete project for water storage and flood protection for
Egypt.=--The complete project for water storage and flood protection for
Egypt as proposed by me, contemplates the following works:--

  Raising the Assuân reservoir (2 years)              £   500,000
  Wady Rayan reservoir (4 years)                      „ 2,600,000
  Training the Rosetta branch                         „   900,000
                                                      -----------
  Total                                               £ 4,000,000
                                                      ===========

To these have to be added the approximate estimates of the proposed
works on the Upper Nile:--

  Regulator for Lake Albert (4 years)                  £  800,000
  Dredging and training works in the Albert Nile and
    the Zeraf river (12 years)                        £ 1,200,000
                                                      -----------
  Total                                               £ 2,000,000
                                                      ===========
  Grand total of works on the Upper and Lower Nile    £ 6,000,000
                                                      ===========

The total expenditure amounts to £6,000,000 spread over 12 years.

The great advantage of undertaking all those works together may be thus
summarized. The increased supply from the Assuân reservoir will be felt
in Egypt after a period of two years. Five years later the waters of the
Wady Rayan will be added to those of the Assuân reservoir, and it will
be possible to increase the cotton crop of Egypt from 6 million to 10
million cwt. It will be possible to allow the Sudan to thoroughly
develop its agricultural resources, and with the aid of the 25,000 horse
power as a minimum which the 6th cataract near Khartoum can supply, to
utilise for its own consumption the waters which can be stored at that
cataract; and, in addition to those, the available supplies from Lake
Tsana provided that that lake is furnished with an outlet tunnel.

While all this life and activity will be developing themselves in Egypt
and the Sudan, the effects of the regulator of Lake Albert and the
training of the Albert Nile in the Sudd regions will be gradually
asserting themselves; and, if the works are being steadily and
perseveringly carried out, it is well within the range of possibility
that before 10 or 12 years will have passed, the additional supplies
from the upper waters of the White Nile will have become so ample, that
it will be possible to dispense with the Wady Rayan as a reservoir. When
this will have happened, the Wady Rayan with its canal will become the
true flood escape of Egypt, like the ancient Lake Mœris, and will, with
the Rosetta branch, afford complete protection to Egypt against the
dangers of a high flood. Egypt, in the fullest meaning of the term, will
be enjoying perennial irrigation and flood protection.

In my book on the “Assuân Reservoir and Lake Mœris” I had recommended a
more extended programme, but the reading of Sir William Garstin’s Report
has convinced me that useful as the Lake Victoria reservoir dam may be,
its postponement as recommended by Sir William is sound, until all the
other works have been executed. The really essential work is the Lake
Albert reservoir dam, of which the study might indeed be commenced
immediately. Sir William’s proposal to train the summer supply of the
Albert Nile and allow the overflow of the floods to find its way through
the Sudd region is so sound and convincing that the necessary training
works in the Sudd region are greatly reduced. With these reductions the
estimated cost of the project for water storage and flood protection for
Egypt is reduced from £8,200,000 to £6,000,000. I have left the Wady
Rayan estimate as it was in my original programme. Mr. Webb’s criticism
of the project was based on facts which are outside the project. He
supposed that the Wady Rayan was to remain a reservoir for all time and
that it was not to be aided by the works on the Upper Nile. Now the
project I proposed and which I propose now, presupposes that the Wady
Rayan will be a temporary reservoir and final flood escape for the Nile,
and that it will be aided in years of very deficient flood by the
gradual improvement of the Upper Nile owing to the works undertaken
there.


37. =Sir William Garstin’s programme for water storage and flood
control.=--In the first appendix to his Report on the Upper Nile, Sir
William Garstin, G.C.M.G., Adviser to the Ministry of Public Works, has
drawn up a programme of works for water storage and flood control in the
Nile valley. He approves of the raising of the Assuân dam for £500,000,
and the conversion of the Rosetta branch of the Nile into a flood escape
for £900,000. He then conditionally approves of a proposal suggested by
Mr. J. S. Beresford, C.I.E., for making a straight cut from Bor on the
Albert Nile to the mouth of the Sobat river at the tail of the Albert
Nile. The line would be 340 kilometres in length and is estimated to
cost £5,500,000, and carry 600 cubic metres per second in summer. In
case of the line being found impracticable when it was surveyed and
levelled, Sir William proposed abandoning the Albert Nile and thoroughly
widening and deepening the Zeraf river for £3,400,000.

As a criticism of the Bor cut project I cannot write anything more
convincing from my point of view than a letter written by me and
published by “The Engineer” in October of this year.

“In your issue of the 16th September Sir Hanbury Brown has reviewed the
scheme suggested by Mr. J. S. Beresford, C.I.E., and conditionally
approved by Sir William Garstin, for diverting the waters of the Albert
Nile (known as the Bahr-el-Gebel) from Bor to the mouth of the Sobat
river, on a length 340 kilometres, and sending them down a canal capable
of carrying 600 cubic metres per second, at an estimated cost of
£5,500,000. In his review Sir Hanbury puts his finger on the weak point
in the project, viz., the difficulty and loss of water entailed at the
crossing of the Albert Nile just upstream of the Sobat mouth. The
difficulty will be got over, as Sir Hanbury himself suggests, by an
earthen embankment provided with a regulator. The loss of water cannot
be got over.

“I have taken the following figures from Sir William’s report and from
the gauge records of the Public Works Ministry:--

DISCHARGE IN CUBIC METRES PER SECOND DURING FEBRUARY, MARCH, AND APRIL
OF THE ALBERT NILE.

                                           1901.  1902.  1903.  1904.

  At Gondokoro above Bor                    600    600    700  1,000
  Upstream of the mouth of the Sobat river  300    300    350    435

“Now, in a year like 1901 or 1902, with 600 cubic metres per second
passing Gondokoro, the diversion canal might be allowed to take in 500
cubic metres per second, leaving 100 cubic metres per second for the
Albert Nile, Atem river, and all the Nuer, Dinka, and Shillook country
between Gondokoro and the Sobat mouth. An allowance of 100 cubic metres
per second would not be liberal, and would probably result in the water
becoming stagnant and very impure; but we shall leave that alone.
Starting with 500 cubic metres per second of clear water the high level
diversion canal would never lose less than 50 cubic metres per second
through percolation and evaporation before it reached the Sobat mouth.
Many authorities would put the loss at 40 per cent., but we shall say 10
per cent.

“We should then have 450 cubic metres per second entering the White Nile
at its head, just at the end of the Albert Nile and at the mouth of the
Sobat river. At this point, however, under normal conditions the Albert
Nile would have been discharging 300 cubic metres per second. This
supply, after the opening of the diversion canal, would have failed
utterly, as the waters of the Albert Nile would have been diverted down
the diversion canal. Whatever water there was in the Albert Nile would,
moreover, have been at so low a level that it could not have flowed down
the White Nile together with the high level water of the diversion
canal. We should therefore have had in a year like 1901 and 1902 a net
gain of 450 less 300 cubic metres per second, or 150 cubic metres per
second at the head of the White Nile. By the time this extra water
reached Assuân it would have become 100 cubic metres per second.

“If this project, or any other project of any kind, is ever to be
carried out on the upper waters of the White Nile, the very first thing
to be done will be to construct a weir or barrage at the outlet of the
Albert Lake, at Wadelai, or lower down at Dufile. I should say, judging
from the map and the cross section, that Wadelai itself would be an
excellent site for a weir. I have advocated this project in season and
out of season these ten years, and now that actual discharges and
figures are before me I am more than ever convinced that I was no untrue
prophet when I wrote in my book on “The Assuân Reservoir Dam and After”
that “the point where Lake Albert ends and the Albert Nile begins to
have a rapid and contracted stream will be the site of the future great
regulator or barrage of the upper waters of the Nile. This work will be
here or at Dufile.” Such a work would cost anything between £400,000 and
£1,000,000.

“If such a work were carried out it would be possible to insure every
year a discharge of between 1,000 and 1,500 cubic metres per second at
Gondokoro from the 15th of January to the 15th of May, _i.e._, during
the months which determine the summer water supply of the White Nile for
Egypt. Such a quantity of water would insure 435 cubic metres per second
at the head of the White Nile, as it has done this year, even under
existing conditions; while with training and dredger work in the Albert
Nile and Bahr Zeraf between Gondokoro and Lake No, it might be increased
to 600 cubic metres per second, and even more. The way in which this
work of training should be carried out has been admirably laid down on
page 174 of Sir William’s Report”.

There are moreover other reasons I think for condemning the excavation
of a straight cut 340 kilometres in length across the eastern corner of
the Sudd regions. The reasons are to be found in Sir William Garstin’s
Report itself. One of the most interesting features of this report is
the number of actually measured discharges at different sites. Of all
these sites Gondokoro, the southern key of the Sudd region, is the most
interesting.

It is very evident from an examination of Sections Nos. 18, 19, 26 and
27, Plate VIII of Sir William’s Report, that the Albert Nile at
Gondokoro scours out its bed very severely after a high flood like that
of 1903. The width of the section is about 230 metres with vertical
sides, and yet while a gauge of ·50 metres on the 1st April 1903 (after
the low year of 1902) gave a section of 615 square metres; on the 9th
September 1903 (after a good year), the section was 1,347 square metres
for a gauge of 2.33 metres. In other words, a rise of 1.83 metres gave
an increased section of 732 square metres; while, if the bed had not
scoured, it would have been 421 square metres. We have here an increase
of 311 square metres, or more than 1 metre of scour. All this happened
in 5 months, and proves that the clear water of the lakes, when in
volume, has a fine cutting edge.

In footnote (2) of page 116 of his Report, Sir William Garstin says that
in the parts of the river where the sudd has been cleared there are
indications that a scour of the bed has set in. Again, on page 55 of the
appendix, he says that the removal of the sudds has caused the levels of
the shallow lakes to fall. All this proves that if the spills and
escapes from the Albert Nile were closed with ambatch, as proposed by
Sir William Garstin on page 175, and a few dredgers put into the Albert
Nile and the Zeraf river the expenditure of a sum of money very moderate
indeed compared with £5,500,000 would in all probability result in the
two rivers being so widened and deepened that they could carry the full
summer supply of the lakes, and so there would be a resulting economy of
over £4,500,000 in the new channel from Bor which, when it began
working, might introduce on an aggravated scale all the difficulties of
to-day in the Albert Nile.

A good description of certain spills is given on page 112 of the Report,
a good idea of scour in Plate XXIX., opposite page 110, while on page
181 Sir William Garstin makes the remark that the experience of American
engineers has taught us that though in theory it may be possible to
shorten or straighten a great river, in actual practice it is
accompanied with almost insurmountable difficulties. If the new channel
were dug and set working, in a few years it might be as crooked as the
Albert Nile itself, unless it were protected with stone along its entire
length.

In my project for deepening and widening both the Albert Nile and the
Zeraf river to enable them to carry 600 cubic metres per second, I think
I have given very solid reasons against abandoning the Albert Nile and
sending the whole supply down the Zeraf river at a cost of £3,400,000.

I cannot but think that Sir William Garstin’s recent objections to the
Albert Nile are founded on an oversight. He has, apparently, not kept
the flood discharges of the Albert Nile at Gondokoro and above the Sobat
mouth sufficiently apart from those of low supply. It is the Sobat
flood, combined with the poor carrying capacity of the White Nile, which
is the disturbing factor, and not any inherent viciousness in the
Albert Nile itself. The Albert Nile has a good section, and, if it were
trained in conjunction with the Zeraf river, would, I feel confident,
discharge all the water required with a very moderate expenditure of
money. This, I always understood, was Sir William’s own opinion. In such
projects it is wise to remember Horace’s saying, “Naturam furcâ expellas
tamenusque recurrit.”


38. =Project for converting the basin irrigated lands of Upper Egypt
into perennially irrigated lands.=--No consideration of this question
would be complete without first examining into the changes which would
be made in the regimen of the Nile flood by the contemplated conversion
of basin irrigation into perennial irrigation. This question was
examined very thoroughly by me in 1892 and 1893 and I give here my
arguments for not anticipating any serious difficulties.

We have to consider the effect of the introduction of perennial
irrigation on the regime of the Nile. The perfection of the perennial
irrigation of the Delta north of Cairo will in no way affect the Nile in
flood. The canals will continue to run as they do at present, and the
question of conversion in Lower Egypt is therefore quite independent of
the subject of flood protection. In Upper Egypt, however, we have
1,460,000 acres of basin irrigation; and as each acre receives in a low
flood 80 cubic metres of water per day, in an ordinary flood 130 cubic
metres per day, and in an extraordinary flood 170 cubic metres per day,
while the demands of perennial irrigation are only 25 cubic metres per
acre per day, it will readily be understood that we are dealing with a
quantity of water which demands the greatest attention.

To foretell with exactitude the anticipated changes in the regime of the
Nile, it is necessary to know first the daily gauges of the Nile at
Assuân and Cairo for a period of at least twenty years, and the
discharges corresponding to these gauges. The difference between these
discharges represents the consumption of water. We have next to
determine the amount of water which passes into the canals, the amount
utilised in filling up the trough of the Nile and covering the berms,
and the amounts evaporated and absorbed. We know that the last three
items are constant while the canal discharges are variable and depend on
the system of irrigation and, if our data are correct, we can tell with
moderate certainty what changes in the level of the Nile will follow
certain changes in the system of irrigation.

Tables 65 and 67 of Appendix L contain the Assuân and Cairo gauges for
typical years in a period of twenty years from 1873 to 1892, and the
mean gauges of these twenty years. Finding it impossible to understand
the Nile without first referring every gauge to some uniform standard, I
have had to choose the line of reference. The mean high water level and
the mean low water level are both available. In Egypt the mean high
water level varies very considerably whether we take it in August and
the early part of September when the basin canals are running full
supply, or in the latter half of September when the canals are running
only half supply, or in October when the basins are discharging back
into the Nile. Early and quick rising floods have a different series of
levels from slow and late floods; while again the recent works carried
out in Upper Egypt by Col. Ross have so increased the discharging
capacity of the canals that the flood gauges have been appreciably
affected. All this points to the conclusion that the mean high flood is
no satisfactory standard. The mean low flood on the other hand is much
less liable to change and is very fairly constant from year to year.
High floods are certainly followed by scouring out of the bed, and low
floods by a silting up of the channel, but the changes are very moderate
compared to those in high flood. I have chosen the mean low water level
as the line of reference, and referred all gauges to it. From the mean
of twenty years’ observations, this level at Assuân is R. L. 85 metres.
By observations along the Nile generally, and by calculations at Cairo,
I have fixed it at all important places north of Assuân. Table 46 of
Appendix K gives the Reduced Levels at different places, while it is
also drawn on the longitudinal section of the Nile in Plate XII. It was
on this system that the ancient Egyptian engineers worked the Nile. They
however chose the mean high water level during the early part of the
flood as their standard of reference and consequently made the so called
cubits in the flood reaches of the Cairo gauge half cubits. This means a
discharge of 1600 cubic metres per second and fairly represents the
discharges of the basin canals in flood. When it is considered that the
level of the Nile valley is raised by about 10 centimetres per 100 years
it will be seen that the old Cairo gauge, which was a living record 1500
years ago, is to-day a meaningless anachronism. It has also to be
compared with the Assuân gauge which was erected in Ismail Pasha’s time
with an arbitrary zero some 90 centimetres below mean low water level,
and which may be reading 17 cubits while Cairo may be recording 25
cubits. The Cairo gauges in winter and summer are no records of
discharge as the afflux from the Barrage affects them. To find the
discharge at Cairo during these months, I have added those of the
Rosetta and Damietta branches and the Delta canals upstream of the
Barrage. When the Nile falls below mean low water level, the gauges are
recorded as minus quantities.

Discharge sites having been chosen for the Assuân, Assiout and Cairo
gauges on the Nile, a continuous series of surface velocity
observations, cross sections and slope measurements were made during
1892 and 1893 and the resulting discharges recorded. Curves of discharge
have been drawn and referred to the gauges of twenty years and modified
until finally a curve has been found which will suit any year whether it
is a maximum or a minimum. In connection with this subject, it must be
remembered that the Nile bed is raised by silt during low floods and
scoured out during high floods and that consequently August and
September discharges vary considerably at times from October and
November discharges for the same gauge. In addition to this, it must
also be borne in mind that the slope of water surface and that
consequently the discharge of a flood during the rise is far greater
than during the fall for the same gauge reading. Indeed the Nile often
discharges more when it is 30 centimetres below its maximum and rising
fast than when it has reached its maximum and begun to fall. It is owing
to this fact that we often see the discrepancy of the Assuân gauge
reaching its maximum a day before Halfa which is 350 kilometres higher
up the river. The discharge depends on gauge and slope, and the gauge
only records one element. Keeping these facts in my mind, I saw that it
was of no use recording the gauges to two places of decimals and
covering paper with useless figures, and consequently I have chosen the
higher unit for a rising gauge and the lower for a falling gauge when I
have been dealing with discharges.

Flood discharges have been taken of all the canals in Upper Egypt
through 1892 and 1893 and have been recorded in Tables 48 and 49 of
Appendix K. From these tables, Table 47 has been compiled which gives
rough approximate discharges of the canals corresponding to the Assuân
gauges in the first half of the flood.

To obtain information about the trough of the Nile, the area exposed to
evaporation and the area of absorption, a longitudinal section of the
Nile from Assuân to Cairo has been levelled, and cross sections taken at
every 3 kilometres. The kilometrage on Plate XII counts from the Assuân
gauge and is measured down the centre of discharge of the flood, since
it is with flood discharges that we are principally dealing. As the Nile
winds about considerably and is often broken into numerous channels, the
areas of the cross sections vary very appreciably according as they are
taken at right angles to the centre line of discharge or of the deep
channel of the river. The former gives the more reliable results. I have
taken 8 millimetres per day as the evaporation during flood in Upper
Egypt. The absorption has been calculated from the water consumption
during the floods of 1892 and 1893, and found to be about 300 cubic
metres per second between Assuân and Assiout, where there is practically
no perennial irrigation. Between Assiout and Cairo, where there is a
considerable length of perennial irrigation on one bank and limestone
rock on the other, the absorption is about 100 cubic metres per second.

When perennial irrigation has once established itself in Upper Egypt, we
may assume that the absorption during flood will be halved in quantity
for the reasons given above, and become 150 cubic metres per second
between Assuân and Assiout, and 50 cubic metres per second between
Assiout and Cairo. The amount of water expended in irrigation will be
about 700 cubic metres per second. The evaporation during flood will be
approximately 120 cubic metres per second. The quantity of water needed
to fill the trough of the Nile will depend on the gauges and may be
calculated from table 43 of Appendix K. The last item will be the only
variable one and the others may be approximately tabulated as follows:--

_Expenditure of water in flood in cubic metres per second_:

                         BETWEEN ASSUÂN  BETWEEN ASSIOUT    TOTAL
                          AND ASSIOUT.      AND CAIRO.
  Perennial irrigation         350              350          700
  Evaporation                   65               55          120
  Absorption                   150               50          200
                               ---              ---         ----
      Total of above           565              455         1020
                               ===              ===         ====

Taking these quantities and calculating directly for the filling of the
trough from the gauges themselves, I have collected in Tables 50 to 52,
the Cairo gauges corresponding to the Assuân gauges for the high years
1874 and 1878 and the minimum year 1877. As far as the more important
results are concerned, I tabulate them here:--

=Gauges at Assuân and Cairo.=

  ============+=======================+=======================+
     Date.    |         1874          |         1878          |
              +-------+-------+-------+-------+-------+-------+
              |Assuan.| Cairo | Cairo |Assuan.| Cairo | Cairo |
              |       | with  | with  |       | with  | with  |
              |       | basin | peren-|       | basin | peren-|
              |       | irri- |  nial |       | irri- |  nial |
              |       |gation.| irri- |       |gation.| irri- |
              |       |       |gation.|       |       |gation.|
  ------------+-------+-------+-------+-------+-------+-------+
  August     5|  6·9  |   ..  |   ..  |  5·6  |   ..  |   ..  |
            10|  7·4  |  6·5  |  5·8  |  5·3  |  4·9  |  4·4  |
            15|  8·5  |  6·9  |  6·4  |  7·2  |  5·4  |  5·2  |
            20|  8·6  |  7·3  |  7·8  |  7·5  |  6·0  |  6·3  |
            25|  8·7  |  7·5  |  7·9  |  8·1  |  6·3  |  6·5  |
            31|  8·7  |  7·6  |  8·1  |  7·6  |  6·6  |  7·2  |
  ------------+-------+-------+-------+-------+-------+-------+
  September  5|  9·0  |  7·7  |  8·2  |  8·1  |  6·5  |  7·5  |
            10|  8·8  |  8·0  |  8·3  |  8·5  |  6·8  |  7·5  |
            15|  8·7  |  8·2  |  8·4  |  8·9  |  7·2  |  8·0  |
            20|  8·4  |  8·3  |  8·5  |  8·9  |  7·6  |  8·5  |
            25|  8·4  |  8·4  |  8·2  |  9·0  |  7·9  |  8·5  |
            30|  8·2  |  8·4  |  8·2  |  9·1  |  8·2  |  8·5  |
  ------------+-------+-------+-------+-------+-------+-------+
  October    5|  7·9  |  8·7  |  7·9  |  8·9  |  8·4  |  8·6  |
            10|  7·6  |  8·5  |  7·6  |  8·5  |  8·7  |  8·6  |
            15|  7·2  |  8·3  |  7·4  |  7·9  |  8·4  |  8·4  |
            20|  6·6  |  8·0  |  7·0  |  7·6  |  8·1  |  8·0  |
            25|  6·2  |  7·7  |  6·3  |  7·4  |  7·9  |  7·4  |
            31|  5·6  |  7·0  |  5·9  |  6·8  |  7·7  |  7·2  |
  ============+=======+=======+=======+=======+=======+=======+

  ============+=======================+=======================
     Date.    |          1892         |          1877
              +-------+-------+-------+-------+-------+-------
              |Assuan.| Cairo | Cairo |Assuan.| Cairo | Cairo
              |       | with  | with  |       | with  | with
              |       | basin | peren-|       | basin | peren-
              |       | irri- |  nial |       | irri- |  nial
              |       |gation.| irri- |       |gation.| irri-
              |       |       |gation.|       |       |gation.
  ------------+-------+-------+-------+-------+-------+-------
  August     5|  6·3  |   ..  |   ..  |  4·9  |   ..  |   ..
            10|  6·8  |  5·3  |  5·1  |  5·4  |  4·0  |  3·9
            15|  6·7  |  5·8  |  5·8  |  5·8  |  4·7  |  4·6
            20|  7·4  |  5·4  |  6·2  |  6·4  |  4·6  |  5·0
            25|  8·3  |  5·8  |  6·5  |  6·1  |  5·3  |  5·5
            31|  8·3  |  6·6  |  7·7  |  6·2  |  5·3  |  5·6
  ------------+-------+-------+-------+-------+-------+-------
  September  5|  8·6  |  6·9  |  7·7  |  6·3  |  5·2  |  5·2
            10|  8·8  |  7·1  |  8·0  |  6·1  |  5·3  |  5·3
            15|  8·8  |  7·5  |  8·3  |  6·0  |  5·2  |  5·5
            20|  8·9  |  7·9  |  8·3  |  6·0  |  5·2  |  5·4
            25|  8·6  |  8·1  |  8·4  |  6·3  |  5·1  |  5·4
            30|  8·4  |  8·3  |  8·4  |  6·1  |  5·3  |  5·6
  ------------+-------+-------+-------+-------+-------+-------
  October    5|  8·2  |  8·4  |  8·3  |  5·6  |  5·2  |  5·4
            10|  7·8  |  8·3  |  8·1  |  5·2  |  5·0  |  5·0
            15|  7·4  |  8·1  |  7·7  |  4·9  |  4·9  |  4·6
            20|  7·2  |  7·9  |  7·2  |  4·6  |  4·6  |  4·4
            25|  6·8  |  7·9  |  7·0  |  4·5  |  4·4  |  4·0
            31|  6·3  |  7·8  |  6·6  |  4·0  |  4·2  |  3·9
  ============+=======+=======+=======+=======+=======+=======

To enable one to compare these figures which are in metres and referred
to mean low water level, with the gauges as recorded at present, I add
the following table:--

  =========================++=========================
          ASSUAN           ||        CAIRO
  ----------+--------------++----------+--------------
    Real    |     Gauge    ||  Real    |    Gauge
    gauge   |  as recorded ||  gauge   | as recorded
  in metres.|   in cubits  ||in metres.|  in cubits
            |   and 24ths. ||          |  and 24ths.
  ----------+--------------++----------+--------------
            |              ||          |
            |Cubits. 24ths.||          |Cubits. 24ths.
     0.0    |   1     13   ||   0.0    |   6      9
      .5    |   2     12   ||    .5    |   7      7
     1.0    |   3     10   ||   1.0    |   8      5
      .5    |   4      8   ||    .5    |   9      4
     2.0    |   5      6   ||   2.0    |  10      2
      .5    |   6      4   ||    .5    |  11      0
     3.0    |   7      3   ||   3.0    |  12      0
      .5    |   8      1   ||    .5    |  13      0
     4.0    |   8     23   ||   4.0    |  13     23
      .5    |   9     21   ||    .5    |  14     21
     5.0    |  10     20   ||   5.0    |  15     19
      .5    |  11     18   ||    .5    |  17     12
     6.0    |  12     16   ||   6.0    |  19      8
      .5    |  13     14   ||    .5    |  21      4
     7.0    |  14     12   ||   7.0    |  22     12
      .5    |  15     11   ||    .5    |  23     10
     8.0    |  16      9   ||   8.0    |  24      9
      .5    |  17      7   ||    .5    |   5      7
     9.0    |  18      5   ||   9.0    |  26      5
  ----------+--------------++----------+-----------
  16 cubits at Assuân corresponds to 7.8 metres.
  17   „    „    „      „         „  8.3   „
  18   „    „    „      „         „  8.9   „

  A cubit is known in Egypt as a pic.
  -------------------------------------------------
  16   cubits at Cairo corresponds to 5.1 metres.
  22     „    „    „     „         „  6.7   „
  23     „    „    „     „         „  7.3   „
  24     „    „    „     „         „  7.8   „
  25     „    „    „     „         „  8.3   „
  25¹⁄₂  „    „    „     „         „  8.6   „
  =================================================

The flood of 1874 was an early one and the basins were discharged on a
falling Nile, still they raised the Cairo gauge to 8·7 metres on the 5th
October while it would have risen to 8·5 on the 15th September with
perennial irrigation. The flood of 1878 was an exceedingly late one and
the basins had to be discharged while the river was still very high. By
the 10th October, the river had risen to 8·7 metres at Cairo when the
banks were breached and all future rise stopped. With perennial
irrigation, the maximum gauge of 8·6 metres would have been reached on
the 10th October. The flood of 1892 was at Assuân 10 centimetres below
that of 1874 and 20 centimetres below that of 1878, and midway between
them in point of time. It was also under complete control owing to the
new regulating works on the basins. It rose to 8·4 metres at Cairo on
the 5th October and fell exceedingly slowly. With perennial irrigation,
it would have risen to 8·4 at Cairo on the 30th September and then
fallen rapidly.

Speaking generally, we may say that with perennial irrigation the very
high floods at Cairo will be 15 days in advance of what they are at
present, that they will not rise higher, and that they will fall 15 days
earlier than what they do now. With low floods there will be no
appreciable difference as to date, but the floods will be slightly
higher at Cairo. In ordinary floods, there will be an advance of from 20
to 25 days in the date of the maximum flood, and a maximum gauge at
Cairo 50 or 60 centimetres under the maximum gauge at Assuân. We have so
far considered Cairo only, as the Delta proper depends on the Cairo
gauge. We now turn to the Nile in Upper Egypt itself: south of Sohag,
there will be no serious change in levels, but the Sohagia and Ibrahimia
canals between them carry at present 750 cubic metres per second in
excess of what they would carry if there were perennial irrigation in
Egypt, and the greater part of this water is not returned to the Nile
until the Kushesha escape is reached. The reach of the Nile from Sohag
to Kushesha is the one which will experience the greatest changes, and I
calculate that there will be a rise of 40 centimetres as compared with
the maximum gauges under basin irrigation.

It will be noted that at the beginning of this paragraph I stated that
“the perfection of the perennial irrigation of the Delta north of Cairo
will in no way affect the Nile in flood.” This had reference only to the
quantity of water taken from the Nile in high floods. There is however
one very serious aspect of this question. The regulation on the Barrage
in low floods, which has gone on steadily since 1899 when Sir Hanbury
Brown used the Barrages in flood for the first time, has enormously
increased the value of the works, but it has certainly caused the Main
Nile to silt, and probably also the branches, owing to a reduced
discharge and velocity of the silt-bearing water, whose capacity to
carry on that quantity of silt depends on its velocity. It seems to me
that unless steps are taken to insure the scouring out of this silt by
the clear water of November, December and January the consequences will
be very serious. High floods scour out their beds, but if a very high
flood were to come early before the silt had been scoured out, it might
overflow the banks near Cairo or in the middle reaches of the Nile
branches in the Delta.

Sir William Garstin has estimated the cost of converting the existing
basins of Upper Egypt into perennially irrigated land at £7,000,000,
thus made up:--

  Conversion of Upper Egypt basins            £ 5,000,000
  Two barrages between Assyut and Kena        „ 2,000,000
                                              -----------
                                        Total £ 7,000,000
                                              ===========

The resulting land tax from the improved irrigation in Upper or Lower
Egypt he has estimated as follows:--

  Upper Egypt. {Basin land converted    750,000 acres @ £ ·50 = £ 375,000
               {Land irrigated by pumps 100,000   „   @ £ ·30 = „  30,000
  Lower Egypt.  Reclaimed land          800,000   „   @ £1.00 = „ 800,000
                                                                ---------
                                               Total          £ 1,205,000
                                                                =========


39. =Development of the Sudan.=--Lord Cromer’s wise decision to
construct the Suakin-Khartoum railway immediately and the Abu
Hamed-Dongola railway as soon as possible, is the charter of the
development of the Sudan. With these railways and especially the former
in working order, we can arrange for irrigation works for the production
of cotton and wheat for export, knowing that they can be exported at a
cost of transport which will not be absolutely prohibitive. The soil of
the Sudan along the Blue Nile, the Atbara, the Main Nile and a great
part of the White Nile is the same as that of Egypt itself. It has all
come from Abyssinia. When at Khartoum last February, I collected
specimens of typical Gezireh soil from points 10 miles south of Khartoum
and from near Khartoum itself. They were analysed by Mr. Frank Hughes
and reported on by Mr. Foaden.

The specimens were numbered as follows:--

(1) Typical Gezireh soil from a point 10 miles south of Khartoum near
the Blue Nile.

(2) Typical Gezireh soil from a point 2 miles south of Khartoum near the
White Nile.

(3) White Nile side under cultivation in 1904.

(4) White Nile side below flood level.

(5) Blue Nile side, not so common as (1).

(6) The sandy soil generally within 5 miles of Khartoum.

Nos. 1, 2, 5, and 6 are above high flood level of both Niles.

“The nitrogen and salt were determined in the samples, as received,
without drying.

        Nos.    1     2     3     4     5     6

  Nitrogen    0·078 0·059 0·062 0·057 0·056 0·052
  Common salt 0·050 0·020 0·010 0·090 0·170 0·020

“All contain abundance of carbonate of lime; Nos. 1 and 2 might almost
be called calcareous. All gave a strong reaction for phosphoric acid,
and there is therefore every reason to believe that they are rich in
this ingredient. So far as the texture of the soils is concerned, little
can be said except that they differ from those previously examined for
Kena Mudirieh, in containing a large amount of coarse sand 1-3 m.m.,
which is entirely absent in most Egyptian soils; No. 6 would probably be
too light for agricultural purposes in its present condition.

“The nitrogen is as high as one would expect but is lower than is
necessary for fertile soils. It would be necessary therefore to
encourage the growth of leguminous crops to increase the quantity of
nitrogen in the soil and to employ nitrogenous manures. It must be borne
in mind that in soils of this class the nitrogen is usually in a highly
insoluble and un-nitrifiable form.

“The salt is in no case high; 0.25% is usually considered to be the
limit for satisfactory growth; all the samples are well below this
limit.”

I had complete analyses made of numbers (1) and (2). The results were as
follows:

                                       No. 1    No. 2

  Silica etc. insol in mineral acid    74.76    73.85
  Lime (Ca.O.)                          6.07     4.56
  Carbonic Acid (C.O.₂)                 3.64     2.40
  Equal to Chalk (Ca.C.O.³)             8.27     5.46
  Potash                                0.23     0.34
  Phosphoric Acid                       0.14     0.12
  Organic Matter                        2.88     4.07
  Nitrogen                              0.075    0.062
      Calculated on soil dried at 100°.

Though none of these specimens contained salt in excess, Nile deposit in
certain localities has very large proportions of common salt and
sulphate of soda. The dark soil near the Atbara mouth at El-Damer is
largely exploited for common salt, while similar soil south of Khartoum
is free from it.

The extent of this Nile deposit soil is very great indeed and if
irrigation could be assured, there would be a great future before the
Sudan.

In Mr. Dupuis’s Report which is the last appendix to Sir William
Garstin’s Report, he speaks of this soil as being met with on the Blue
Nile, on the Rahad, on the Atbara and on the Gaash. From Khartoum
northwards the main Nile flows between berms of this soil.

The extent and quality of this soil may therefore be considered as an
undisputed asset of the Sudan. We have next to consider the seasons.

A reference to tables 76, 77, and 80 will show how much warmer the Sudan
is than Egypt, and any attempt to introduce Egyptian methods into the
Sudan without modifications will not at once turn the Sudan into Egypt.
I allow that extensive plains of irrigated land greatly moderate the
heat as they have already done in Middle Egypt; but we have to begin
from the beginning in the Sudan, and there are no extensive plains of
irrigated land. Basin irrigation will be a failure in the Sudan unless
it is supplemented by two or three waterings in the winter, for all
crops except the cheapest and coarsest leguminous crops. Wheat must be
irrigated in winter whether sown in a basin or on the Nile berm, except
in a few choice, low and damp localities. Cotton, on the other hand,
which has to be sown in spring in Egypt and reaped in autumn will need
such an extraordinary quantity of water to pull it through the summer
that it will be found preferable to grow it in June with the rising
flood and reap it at the end of the winter. Irrigation therefore from
June to October for Indian corn, from June to February for cotton, and
from November to February for wheat will be essentials of a good harvest
in the Sudan.

We now come to the question of the water supply. Unless permits are
given for pumps to work from the 15th June to the 15 February, the
cultivation of cotton and wheat on any scale in the northern part of the
Gezireh, along the main Nile between Khartoum and Dongola, and on the
lower reaches of the Atbara will be out of the question. Maize and
millets and some of the coarser leguminous plants might be developed by
pumps with permits to work from 15th June to 15th October, but it would
pay no one to put up pumps on these terms.

Fortunately for the joint interests of Egypt and the Sudan, though Egypt
cannot spare water between the 15th March and 30th June, which would
correspond to 1st March and 15th June in the Sudan; she has enough to
spare for pumps at other times, though she has not always enough to
spare for large free flow schemes in the Sudan. Free flow schemes in the
Sudan, except during high and good floods, have however yet to be found.

Speaking generally we may say that the agricultural success of the Sudan
will depend on permits for pumping engines to work between the 1st June
and the end of February. There should be no difficulty in the way of
such permits being given. We have spoken so far of schemes within the
power of individuals and companies. Of schemes which the Government
alone could carry out by itself or in conjunction with powerful
companies, the most promising seem to be those which are connected with
the 6th cataract. This cataract seems well suited for the construction
of a solid dam to create power and develop electricity to work pumps
between it and Khartoum, and some 30 kilometres up the Blue Nile; and if
possible to allow of a canal down the left bank of the Nile as far as
Berber. This project might be studied with advantage and a greater
amount of water storage for summer use be also obtained.

[Illustration: PLATE XX

SKETCH PLAN OF

COUNTRY ABOUT DELGI

N.W. OF L. TSANA

_Scale 1 : 50.000_

Lith. Sur. Dep. Cairo.]

Another scheme is the construction of a double barrage and weir near Wad
Medani on the Blue Nile, with canals irrigating the Gezireh and the
right bank of the Blue Nile and the Nile to Shabluka. Unfortunately no
cross sections have been taken of the Blue Nile showing how high the
Gezireh is above the bed and water surface of the Blue Nile at Wad
Medani. A weir further south would, as Mr. Dupuis states, entail very
expensive canals to irrigate the lands south of Khartoum.

Mr. Dupuis’s report on the Atbara is not very hopeful. Without
reservoirs this torrential river could insure no crop except millets and
Indian corn. The same may be said for the Gaash. Basins without winter
irrigation would, I think, be most unsatisfactory.

Examining Mr. Dupuis’s figures and sections for the outlet of lake
Tsana, I calculate that this reservoir would not supply a fraction of
the water estimated by Mr. Dupuis. If I were wrong, and I should be
pleased indeed to be wrong here, a tunnel along the alignment roughly
surveyed by Mr. Dupuis, Plate XX, leading the waters of Lake Tsana into
the Rahad river, and from there under the Blue Nile by a syphon, and
branch canals irrigating both banks of the Rahad and both banks of the
Blue Nile to Khartoum, would be one of the boldest projects in the
world.

It will be noted that no mention has been made of the tracts between the
foothills of Abyssinia and Wad-el-Medani which can produce good crops of
Indian corn, millets and even cotton in nine years out of ten with the
aid of rain without irrigation. If the land could lend itself to basins
similar to those of Bundelkund or to river fed pans as in Madras, a
development of this country would be possible. Ordinary Egyptian basin
irrigation would be, I think, of no use.

The following quotations from a letter written by Messrs. Choremi,
Benachi and Co., of Alexandria, to Mr. Foaden on the 8th February 1904,
will give an idea of the estimation in which Sudan grown cotton is held
in Alexandria:--

“The cotton generally is good and superior to any Sudan cotton I have
yet seen. Last year the best I saw was sent by the Sudan Government and
grown in Miralai Stanton Bey’s garden, with artificial irrigation and
quality was (first picking) class “good”, equal to Beni-Suef or Minieh
cotton, but more woolly. In any case it is saleable cotton for coarse
Nos. of Yarn, not what we call Bolton Spinners’ cotton.

“I now give you the following classification and values compared to
Standard of Full Good Fair Lower Egypt which is the basis of “Futures”
in our Market and Liverpool.

“On Upper Egypt the outturn in ginning on basis 315 lbs. per cwt. in
seed runs from 100 to 104, and Lower Egypt 105-110 according to province
grown and quality of seed.

  No. 1 Outturn  96     Class “good”, value P.T. 5 over Delta fully good
                        fair--colour rather light--good staple, better
                        than Beni-Suef Ashmouni or even Afifi.

  No. 2   „      98¹⁄₂  Long staple and finish does not look grown from
                       afifi seed but from superior quality, value about
                       P.T. 15 over F.G.F.

  No. 3   „      99     Class “good”, the seed of this is from
                        Delta because mixed--there is also some
                        Abassi in and does not look as from afifi
                        seed because finer than any afifi grown in
                        Minieh and Beni-Suef, value 5 to 10 over
                        F.G.F.

  No. 4   „     102¹⁄₂  “Good” in class, from mixed seed--some looks
                        afifi, other better, probably Yannovich
                        seed. There are traces of abassi--and is
                        irregular in strength, value P.T. 15 to 20 over
                        F.G.F.

  No. 5   „     100     Also from mixed seed--I can trace afifi quality
                        and Yannovich, also some abassi. Value over
                        F.G.F. about 7 to 10 P.T.

  No. 6   „     103¹⁄₂  About same as No. 5 and with same mixture.

“From the above report you will see that quality generally is good--but
I regret the seed got mixed--probably through mistakes in transport or
if in single bags some broke and seed became mixed.

“The outturn in ginning I consider good and the seed I notice
deteriorates but very little as you can see--though with that of Stanton
Bey’s I examined with you last year, the deterioration was, if I
remember right, something like 10% in one year. The seed from the non
irrigated Sudan (I suppose near Khartoum) though from good Afifi seed,
almost becomes unfit for sowing and the quality of this cotton had a
very poor outturn of about 73%.

“Rain crops cannot be depended on, because if no rain for some time the
quality will be totally spoilt.

“I fail to find any trace of sand in the samples--though the common
Sudan non-irrigated cotton was very dirty and sandy.”

The following extracts from a letter written to me by Ibrahim Effendi
Fahmy, originally a student of the Cairo Agricultural College and at the
time of writing Government agriculturist at Khartoum and on leave in
Cairo, will be found interesting.

“There are three seasons in the Sudan, which are different from those in
Egypt. The seasons are:--1st the winter which extends from the 1st
November to the end of February, in this season wheat, beans, barley,
onions, Indian corn and millets are planted: 2nd, the summer which
extends from 1st March to the 15th June, in this season, practically
speaking, nothing is planted except a small quantity of millets, and in
the middle of the season from the 1st May to the 15th June all
agricultural work is stopped owing to the great heat and deficiency of
water: and 3rd, the flood season or “Demera” from the 15 June to the end
of October; in this season the rains fall, the Nile rises and the heat
is decreased, two crops of millets can be taken and cotton, sesame and
earthnuts are sown.

“Manures are the same as in Egypt.

“Cotton sown in March, April and May needs so much water through the
summer that its cost is prohibitive. In the really hot weather it must
be irrigated every three days. High winds and rain hurt the first open
pods, and the pickings are on the 20th August, 20th September and 15th
October. After 22 waterings a good field will give 4¹⁄₂ cwt. per acre.

“Cotton sown in June and July has an even, regular growth. The rains and
moisture in the air encourage the growth of the plant. The height of
the flood permits of easy irrigation even when it is lift. The plants
grow to a great size but have many bolls. The following table will show
the growth of the plants.

  =================+===============+==============+=============
  Date of planting.|No of waterings|First picking.|Last picking.
  -----------------+---------------+--------------+-------------
  25 June          |      16       |  1st January |  March 15
   3 July          |      16       | 15th January |  March 31
  30 July          |      15       | 15th February|  April 15
  =================+===============+==============+=============

“The yield of a good field is 5¹⁄₂ cwt. per acre. The fibre is better
than that of the cotton sown in March and April.

“I consider that June and July are the best months for sowing, and that
cotton sown from well-selected seed and well cultivated will prove
itself a cotton of superior quality, ranking with Egyptian cottons.

“The following table gives the kinds of crops, other than cotton which
can be profitably grown in the Sudan:--

  =================+===========+==========+=========+=================
        Crop       |  Time of  |  Time of | N^{o} of|   Produce
                   |  sowing.  |ripening. |waterings|
  -----------------+-----------+----------+---------+-----------------
  Egyptian wheat   |Nov. & Dec.|  April   |    3    |    5¹⁄₂ ardebs
  Indian wheat     | December  |    »     |    3    |    5       »
  Egyptian barley  |    »      | March 31 |    2    |   11       »
  Australian barley|    »      |    »     |    2    |    5       »
  Beans            |    »      |    »     |    3    |    5       »
  Lentils          |    »      |    »     |    3    |    3¹⁄₂    »
  Earthnuts        |   July    | January  |    9    |    9       »
  Indian corn      |    »      |September |    4    |    6       »
  American maize   |    »      | October  |    7    |    4       »
  Potatoes         | November  |  March   |    3    |  150  kantars
  Lucerne          |  March    |March year|   12    | 1800    »
                   |           |          |         |in 12 cuttings of
                   |           |          |         |150 kantars each.
  =================+===========+==========+=========+=================

“Fodder crops such as birseem and vetches (gilban) when well watered are
satisfactory.

“If the land is not well tilled, manured and looked after, wheat will
require 6 waterings and barley 4 waterings.

“If water can be obtained in the Sudan, the agricultural problem is very
easy.”

I cannot do better than close this chapter with this thoroughly Egyptian
remark of Ibrahim Effendi Fehmy.




CHAPTER V.

_The Oases and the Geology of the Nile valley, by Mr. H. J. L. Beadnell,
F. G. S., F. R. G. S._


40. =The Oases.=--The chief oases[6] of the Libyan desert--Dakhla,
Kharga, Baharia and Farafra,--occupy extensive depressions cut down
through the horizontal Eocene strata[7] to the underlying saddle of
Cretaceous rocks; some of the more porous beds of the latter are
water-bearing and from them, either through natural passages or through
artificial borings, the water rises to the surface, often under
considerable pressure. The floor level varies considerably but the
cultivated lands in general lie between 70 and 115 metres above sea
level.

  [6] See Geological Survey reports, P.W.M., Cairo.

  [7] With the exception that Dakhla is almost entirely cut out in
  Cretaceous strata.


41. =Dakhla oasis.=--This, by far the most important and prosperous of
the Egyptian oases, lies three days’ march west of Kharga, or about 300
kilometres due west of Armant in the Nile valley. The site is a
depression lying at the foot of the great east and west Cretaceous
escarpment, bounded to the south by the undulating desert of Nubian
sandstone, which stretches unchanged almost to the heart of the
continent. The inhabitants of Dakhla, numbering over 17,000, are
distributed among 12 villages and form a practically self-supporting
community. The cultivable land within the oasis (400 square kilometres)
amounts to nearly 50,000 acres, of which one half is under cultivation;
in addition several extensive areas of alluvium covered ground exist
outside the oasis proper, notably on the Gabbari road between Dakhla and
Kharga. Owing to the difficulty of drainage, salines, saltyland, marshes
and pools occupy some 7,000 acres.

There are nearly 130,000 adult palm trees in Dakhla, a large export
trade in dates being carried on with the Nile valley; the finest crops
of wheat and barley are raised, while the fruits of the oasis, oranges,
apricots, mulberries, etc., are abundant and of excellent quality.

Taxes are levied as follows:--(1) Mature date-palms are taxed 1¹⁄₂
piastres each per annum; (2) Modern wells (i.e. biyâr, made with the
existing boring plant) pay 50 piastres per annum per qirat of water; (3)
Ancient wells (aiyûn) pay the same, except that in some cases those used
for irrigating palmgroves are exempt. There are 7¹⁄₂ trees and 1¹⁄₂
acres per inhabitant, and the total tax paid by the community is about
£E. 2,500.

The water-supply of the oasis is derived from an underground bed of
sandstone, 55 metres thick, underlying a dense impervious red clay 45
metres in thickness; the upper part of the latter is conspicuous
throughout the oasis, underlying the alluvium and forming the base of
the surrounding escarpments in many localities. Below the water-bearing
sandstone lies a black clay, never yet penetrated by the boring rods; it
is probable that other water-tables exist below and such would be
invaluable for the irrigation of those parts of the oasis where the
present supply is unsatisfactory. There seem to be no natural springs
extant at the present day, the whole of the water-supply being through
boreholes, both ancient and modern. The old wells, known as _ain_,
_aiyûn_, appear to be mostly of early Egyptian and Roman construction,
and number over 400; exactly similar wells have been sunk by boring
plant during the last few decades and are called _bîr_, _biyâr_; there
are over 160 of these; all are true artesian wells. At the present day
the method in vogue is as follows:--a two metre square timbered shaft is
sunk by hand to the base of the red clay and within this is built up a
watertight wooden pipe, 35 cm. in diameter, made of ‘sunt’ (a species of
thorny acacia), the surrounding space being packed with clay. Sinking is
continued in the sandstone with the boring machine until a satisfactory
flow of water is obtained. Many of the older wells in the oasis have
become choked up, and although some have been successfully cleaned out
by the inhabitants, but the process is costly and laborious and
frequently fails. The work is done by divers, a small but hardy class
only found in Dakhla and Farafra.

The output of wells is determined in a somewhat rough and ready manner
by measuring the depth of water passing over a weir fixed in the stream.
It is reckoned in qirats, one qirat being a water-section of 64 square
centimetres; from some test observations in Kharga Dr. Ball deduced the
average value of a qirat, as measured in that oasis, as 230 litres a
minute. The total water-output in Dakhla (1096 qirats) may thus be taken
as approximately representing a discharge of 132 million cubic metres
per annum, and taking the cultivated lands as 25,500 acres the duty is
6,130 acres per cubic metre per second. That the water-supply could be
largely increased, and the limits of cultivation greatly extended, admit
of no doubt, but with the free hand accorded the natives during the last
few decades a considerable amount of damage has been done throughout the
oasis by the injudicious sinking of wells. Promiscuous boring is fatal,
and strict and efficient control of all boring operations imperative.
Considering the number of wells abandoned owing to a slight fall in the
water-level having caused them to cease running at the surface, the
importance of lifting appliances, in the shape of shadûfs, saqias, or
windmills, is evident, but until a few years ago the oasis was destitute
of such appliances; a number of saqias have recently been fixed in the
village of Mushîa and have met with success, but it is not an easy
matter to persuade the inhabitants to have recourse to lifting
appliances of any description.

Some of the Dakhla wells are of considerable depth; Bir-el-Dinaria, the
most northerly in the oasis, is 144 metres deep and its water emerges
with a temperature of 39·5° C. The best wells yield 9 or 10 qirats,
though before the modern boring operations the output of some was as
much as 16. The terms ‘artesian’ and ‘thermal’ may fairly be applied to
the Dakhla wells, and it is noteworthy that the temperatures as a whole
increase from south to north. The thermal character of the springs may
be considered to be due to the great depths from which the water is
derived, the actual temperature at the point of exit being dependent on
local conditions, such as the depth of the well and the rate at which
the water finds its way to the surface. It is probable that the
water-bearing table has its outcrop in the rainy regions of Darfur,
although some of its water may be derived by direct infiltration from
the Nile in its upper reaches.

[Illustration: PLATE XXI.

THE EGYPTIAN OASES

Scale 1 : 6.000.000]


42. =Kharga oasis.=--Kharga, the easternmost of the two southern oases,
is a north and south lying depression, mostly bounded by steep and lofty
escarpments but open to the south and south-west. A great part of its
floor, which is composed of the Nubian sandstone, is buried under sand
accumulations. There are seven principal villages, besides numerous
hamlets and smaller settlements, with a total population of under 8,000.
Taxes are levied as in Dakhla and amount to slightly over £E. 1000. The
adult palm trees in the oasis number about 60,000 and the cultivated
lands have an area of some 4,500 acres, or half an acre and eight palm
trees per inhabitant. The crops raised do not appear to be sufficient to
support the population, as a certain amount of grain is imported from
Dakhla. Dates are exported to the Nile valley, though in less quantities
than from Dakhla and Baharia.

The general level of the floor of the oasis lies between 50 and 130
metres above sea level, though near Qasr Zaiyan a limited area appears
to lie below sea level. Water is met with in most localities on digging
to a moderate depth, but the best supplies are from deep wells; as in
Dakhla the majority of the wells are of considerable antiquity, though
some have been recently made with modern boring plant. With an increased
water-supply cultivation could be very much extended, as there are large
areas of unoccupied alluvium covered land within the oasis. The same
difficulties exist in Kharga as in the other oases, though here perhaps
aggravated by the encroachments and movements of blown sand, namely, the
lack of control of the wells and water-supply and the apathy of the
inhabitants generally.


43. =Baharia oasis=, lying 180 kilometres west of Minia, is a large
natural excavation 150 metres deep and entirely surrounded by
escarpments. The cultivated lands bear a very small proportion to the
total oasis-area; their general level is 110-115 metres above sea level,
rising to 155 metres at Ain-el-Haiss in the southern part of the
depression. There are four chief villages with a population, inclusive
of outlying settlements, of just over 6,000. The standard of public
health in this oasis is low, mainly owing to febrile disorders. The
total area of cultivated land is about 2,500 acres (barely ¹⁄₂ an acre
per inhabitant), largely made up of palmgroves; rice, wheat and barley
are grown, but the area sown with cereals has of late years being
decreasing in extent owing to a diminished output from the springs.
Baharia is _par excellence_ the date-producing oasis of Egypt and very
large quantities are annually exported to the Nile valley; besides
date-palms the gardens contain numbers of olive, apricot and other fruit
trees. Taxation is on palm trees and land.

The water-supply is derived from the Cretaceous sandstones forming the
floor of the depression, the water rising naturally to the surface of
the lowest areas. In numerous cases long adits have been driven into the
rock to obtain an increased supply; these tunnels communicate with the
surface of the ground by a series of air shafts; they mostly date from
early times. No deep wells appear to exist in the oasis and certainly no
borings have been made in modern times. The fall of the water-level is
probably due to the gradual choking of the passages; an unsatisfactory
and laborious method of cleaning out wells is in vogue but little
trouble is taken to prevent the deterioration of the water-supply
generally. Practically all the available land in this oasis is under
cultivation, although with the reduced output of the springs the supply
is barely sufficient for efficient irrigation.


44. =Farafra oasis= occupies a large semicircular depression 300
kilometres west of Assiut. The floor is formed of the white chalk at the
top of the Cretaceous, but at Ain-el-Wadi, a spring in the north part of
the depression at 26 metres above sea level, the underlying beds are
locally exposed. The solitary village of Qasr Farafra is situated on the
western side at 76 metres above sea level, and contained 542 inhabitants
at the last census. In the entire area there are some 20 springs, mostly
grouped round the village, each irrigating a small patch of cultivated
ground; the total area of the latter, including the few palmgroves,
probably does not amount to 500 acres. Wheat, barley, durra, rice,
onions and some fruit are grown, and small quantities of dates and
olives are exported; formerly the olives of Farafra were celebrated for
their quality, but of late years the trees have deteriorated.

The water rises as springs from the white chalk and does not necessitate
the use of lifting appliances, though the output appears to be
decreasing through natural causes. There are a few examples of
horizontal conducting channels of ancient date and two or three of the
springs appear to have deep vertical shafts as in the ancient wells of
Dakhla. Sweet and brackish water-holes occur in several outlying
localities within the depression, as well as in the neighbouring little
known oasis of Iddaila to the west. Owing to the absence of waste pools
and marshy land the climate of Farafra is more healthy than that of the
other oases.


45. =The Geology of Egypt=[8]. The north-east corner of Africa, lying
between the Red Sea on the east and the sand merged portion of the
Libyan Desert on the west, and stretching from the Mediterranean to the
22nd parallel of north latitude, both in its topographical and
geological characters is distinctly tripartite, as follows:--

(1) A rugged broken undulating sandstone desert, forming the southern
part of the country;

(2) Elevated plateaux, for the most part of limestone, stretching from
lat. 25° N. (approximately) to the Mediterranean;

(3) The mountainous igneous range of the Red Sea Hills, with peaks over
1800 metres (6000 feet) in height.

  [8] In writing this note at the request of Sir William Willcocks I
  have made free use of all sources, of information, but am chiefly
  indebted to the publications of Schweinfurth and the late Professor
  Zittel, Capt. Lyons, and my past and present colleagues on the
  Geological Survey of Egypt.

As a whole one of the most waterless and desolate areas in the world,
the country is traversed from south to north by a narrow highly
cultivated and thickly populated strip of alluvial land, formed and
watered by the Nile. In the southern sandstone country the river
occupies only a shallow valley, but to the north flows over the floor of
a deep gorge cut down from the surrounding limestone plateaux. On either
side of the river are alluvial plains of varying extent, composed of the
finest loam, a fertile soil for the most part formed by the
disintegration of the volcanic rocks of the Abyssinian highlands,
annually denuded by rains and brought down by the Atbara and Blue Nile
floods and deposited in the lower courses of the river. Unlike most
countries therefore, the soil of Egypt has no connection with the
underlying rocks, being entirely of extraneous origin and owing its
existence absolutely to the peculiar conditions of rainfall in Abyssinia
and the direction of drainage from the watersheds of that country.


46. =Igneous rocks.= The most ancient rocks in Egypt are found in the
central igneous ranges of the Red Sea Hills and in the crystalline floor
underlying the sandstones in the southern part of the country.

In Nubia the crystalline rocks consist largely of granite and gneiss,
with associated diorites and schists, traversed by basaltic and felsitic
dykes. Cataracts have been formed at those points where the river
crosses the hard igneous belts, which may be regarded as the summits of
the higher ridges of an old eroded continental land surface.

In the Red Sea Hills the most ancient rocks are the gneisses, schists,
and slates, constituting the metamorphic series of Jebel Meeteq. Next in
succession is a volcanic group, consisting of dolerite and sheared
diabases in the south and of dolerites, andesites, tuffs and
agglomerates in the north. These volcanic rocks are underlaid and
intruded by still younger quartz-diorites and grey granites, and like
them are pierced by masses of red granite and dykes of quartz felsite
and dolerite. The red granite is itself traversed by dykes of diabase,
which are thus the youngest of all, except for the still more recent
andesitic intrusions into the Eocene limestones (occasional occurrences
of which are met with on the plateaux on both sides of the Nile valley),
and the basaltic sheets which commonly mark the base of the Oligocene
sandstones in the north of the country.

The whole of the Red Sea Hills igneous complex has been planed down by
marine erosion, the oldest sedimentary deposits being laid on to the
smoothed denuded surfaces.


47. =Sedimentary rocks.= Geologically the sedimentary deposits of Egypt
are not of great age. Broadly they consist of a great development of
Upper Cretaceous and Eocene strata, followed by more restricted deposits
of Oligocene and Miocene age, the still younger formations being
represented only by comparatively local though important, accumulations.
As a general rule the different members of the Cretaceous and Tertiary
succeed each other in regular order from south to north, the strata
being undisturbed and dipping northwards at a very low angle.


48. =Upper Cretaceous.= The Cretaceous system in Egypt is divisible into
three main groups, (1) a great thickness of freshwater arenaceous
sediments known as the Nubian Sandstone, of Senonian age in the south
(Dakhla, Nile valley, and southern part of Eastern Desert), and
Cenomanian age in the north (Baharia, Abu Roash(?), and Wadi Araba); (2)
300 metres of argillaceous deposits with bone-beds near the base, of
Senonian age; (3) a deep water foraminiferal white chalk (Danian) 60 to
100 metres thick, especially developed in the region of the oases to the
west of the Nile.

The Nubian Sandstone, the oldest sedimentary deposit in Egypt, occupies
a very large area, especially in the south; wherever its base is exposed
and has been critically examined, the sandstone is found to be laid on
to the denuded surface of the underlying crystalline rocks. Thinner
argillaceous bands are almost everywhere associated with the sandstones
and the latter vary much in colour, texture, and hardness. In its widest
sense the term “Nubian Sandstone” includes deposits of much greater age
than Upper Cretaceous, undoubted Carboniferous fossils having been
detected in some localities. The formation must be regarded as
representing the slow accumulation of sediment in immense inland lakes
during a great lapse of time. Although temporary marine invasions left
their mark at intervals, it was not until the Cenomanian that continued
depression caused a steady recession of the shore line from north to
south, so that in Senonian times practically the whole of the country
was occupied by the Cretaceous sea.

North of Silsila in the Nile valley the sandstones gradually give way to
a series of flaggy ripple-marked sandstones alternating with sandy
shales and clays, at the top of which are beds rich in bones and
coprolites of fish, associated with hard oyster-limestones, overlain in
Wadi Hammama, E.-N.-E. of Qena, by a limestone containing abundant
remains of cephalopoda; these beds are of Upper Senonian (Campanian)
age. East of Sabaia, in the Nile valley, they are followed by a 200
metre series of finely laminated clays, separated by bands of marly
limestone, the greater part of which is of Cretaceous age and homotaxial
with the _Exogyra_ clays and white chalk (of Campanian--Danian age)
which in the southern oases follow on the rich bonebeds overlying the
Nubian Sandstone.

Anterior to and during the deposition of these clayey beds in the south,
thick accumulations of limestone were being formed in the more open sea
to the north and are visible to-day in the Cretaceous area of Abu Roash
near the pyramids of Giza, (and to a lesser extent in Jebel Shebrewet on
the Gulf of Suez), where a great complex of limestones of Turonian and
Senonian ages occurs. Finally a deep sea deposit of white chalk forms
the summit of the Cretaceous throughout the Western Desert.


49. =Eocene.= Our knowledge of the junction of the Cretaceous and Eocene
in several parts of the country leaves much to be desired. Where the
Eocene is most fully developed its basal member consists of a group of
green argillaceous deposits, known as the Esna shales, well seen at the
base of the cliffs throughout the Esna-Qena reach of the valley. These
beds everywhere pass conformably upwards into the Lower Eocene (Libyan)
limestones above, but in the Nile Valley and the Eastern Desert the
exact line of demarcation between them and the lithologically similar
Cretaceous clays below is still somewhat obscure. In Kharga and Farafra
they form a well-marked band between the White Chalk (and associated
clays) at the top of the Cretaceous and the Libyan limestone of the
Lower Eocene. The Esna shales may in fact be regarded as passage beds,
and where they exist appear to bridge over the lapse of time which is
represented by a decided unconformity between the Cretaceous and Eocene
in the north of the country, as in Baharia Oasis and at Abu Roash.

The thick mass of limestone which forms the plateaux and cliffs on both
sides of the valley from lat. 25° N. to Cairo is of Lower Eocene (Libyan
stage) and Middle Eocene (Mokattam stage) age. These limestones,
frequently nummulitic and typically marine calcareous accumulations,
exceed 500 metres in thickness, and over a wide area are unrelieved by a
single band of clay or sandstone. Towards the summit of the Middle
Eocene, however, terrigenous deposits were laid down, the Upper Mokattam
consisting of an alternating series of impure limestones, clays, and
sandstones. In the Fayûm the Middle Eocene is followed by a great
thickness of fluvio-marine deposits of Upper Eocene age, in which the
remains of the animals that inhabited the land to the south and the
adjoining seas at the time are abundantly preserved.


50. =Oligocene and Miocene.= Throughout Oligocene and Miocene times
conditions similar to those which led to the deposition of the Upper
Eocene formation in the Fayûm prevailed, accompanied by a continual
retreat of the sea to the north. In the littoral area marine beds were
intermingled with the sediments brought down by rivers from the land to
the south; and throughout these deposits the remains of land animals and
great quantities of large silicified trees are common. A considerable
part of the deserts east and west of the valley north of lat. 29° 30´ is
covered with deposits of this age, and shallow water Miocene beds,
unconformably overlying the Eocene, form marked flanking plateaux to
some of the igneous ranges of the Red Sea Hills.


51. =Pliocene, Pleistocene and Recent.= In Pliocene times the relative
areas of land and sea approximated to those of to-day and powerful
earth-movements initiated the formation of the lower part of the Nile
Valley. The determining faults and the huge blocks of displaced rock are
visible along the cliff walls in many parts of the valley, and at
Gebelain isolated ridges of highly tilted limestone protrude above the
floor of the trough, though as a rule, except near the cliffs, the
faulted rocks are invisible, being buried under great thicknesses of
lacustrine and fluviatile deposits. A few kilometres south of Jebel
Silsila, however, Eocene and Cretaceous limestones are met with at river
level in the centre of the valley and point to the Kom Ombo plain being
let down by a fault of over 400 metres throw.

The Nile Valley trough or “grab” became a marine fiord in later Pliocene
times, sea-beaches being formed up to 70 metres above present sea level.
Extensive terraces of gravel, perched up on the surrounding slopes of
the Fayûm, prove that the sea, or a great inland lake, stood at 180
metres in latest Pliocene or early Pleistocene times. From this time
also dates the Red Sea (in its modern aspect), the highest Older
Pleistocene coral reefs being now found at some 200 metres above
sea-level; younger reefs associated with later Pleistocene gravels occur
at a lower level. In later Pleistocene and early pre-human times, under
the very moist climate which preceded the present desert conditions, the
Nile Valley north of latitude 24° was occupied by a series of deep
freshwater lakes, perhaps co-existent with that in which the Fayûm
gravel terraces were accumulated. The denudation of the surrounding
country was rapid, and tributary streams from the plateaux on either
side brought down fine limestone detritus, which was deposited along the
margins of the lakes in the form of compact beds of re-made limestone,
interbedded with frequent layers of conglomerate and gravel, washed down
by the larger streams and by torrential floods. In the quieter parts of
these lakes clays and calcareous tufas were laid down and are visible
to-day from Kom Ombo to Heluan. Subsequently, owing to the breaking down
of the dividing barriers, or as the result of a general slight
elevation, drainage became more pronounced and the river cut its way
down through these lacustrine deposits. It was probably at this time
that, following the partial removal of the gravel ridge between the
Fayûm and the valley, part of the drainage obtained access to the Fayûm
depression and a lake, the precursor of the historical Mœris, was
formed. Subsequently, under climatic conditions similar to those of
to-day, the accumulation of Nile alluvium commenced within the wide
trough cut out in the older lake beds. Flood plains were formed on
either side of the river, and by successive deposits, at the rate of
about twelve centimetres a century, were built up to their present
level.


52. =Economic products.= Limestones for building and other purposes are
abundant in the Lower and Middle Eocene formations, though as a rule of
only medium quality. The chief quarries are those of Jebel Mokattam,
Tura, Heluan, Abu Foda, Harîdi, and el-Tarif. At Isawia, near Tahta, a
fine tough freshwater tufaceous limestone of Pleistocene age occurs, and
was largely used in the construction of the Assiut barrage. Clays of
good quality are not widely extended, though certain bands of the Esna
shales are very largely used near Qena in the manufacture of pottery.
For bricks the Nile alluvium is used throughout the country.

Sandstone is quarried for local purposes at J. Ahmar near Cairo and in
several localities in the south part of the country; it was formerly
extensively quarried at J. Ahmar for the temples of the Delta, at J.
Silsila for those of Upper Egypt, and at Girtassa, south of Assuân, for
the Nubian monuments. Although a fairly hard and good weather-resisting
stone when carefully selected, the frequent presence of soft uncemented
and clayey laminae gives it an unreliable character, and a good deal of
the decay of many of the ancient Egyptian monuments is attributable to
this cause.

Numerous rocks in the Red Sea Hills and the Nile Valley were worked in
Egyptian and Roman times for ornamental purposes; among them may be
specially mentioned the purple imperial porphyry of J. Dokhan, the green
breccia of Wadis Hammamat and Dib, the dolerite of Wadi Esh, and the
hornblende granite of the first cataract. In modern times local granite
was used throughout the Assuân dam and an Oligocene basalt is quarried
at Abu Zabel and used for road-metal in the capital and other towns.

Old workings and mining camps are of common occurrence in many parts of
the Eastern Desert and there is no doubt that considerable quantities of
gold were extracted by convict labour. The quartz lodes traverse not
only the metamorphic rocks but also some of the granites. Iron
(hematite, limonite), copper (chrysocolla, copper pyrites) and lead
(galena) bearing veins also occur, and turquoise, jasper and chrysolite
are found in certain localities. Petroleum and sulphur occur sparsely
near J. Zeit, and gypsum in large quantities in many parts of the
country.

Phosphate deposits in the form of accumulations of bones, teeth and
coprolites of fish in compact beds, have a wide distribution in the
Eastern Desert, the Nile Valley and the southern oases, though these
beds have not yet received the attention their importance deserves.
Better known are the nitrate bearing clays which are so highly valued
and largely used by the fellahin throughout the country. The chief
horizons are the Esna shales and the underlying cretaceous clays, but
disintegrated clays of every age are worked throughout the country,
though their nitrate content may be very low and their salt content
high; more prized still is the material from the middens marking the
sites of ancient towns.

Natron (carbonate of soda) and salt are associated in considerable
quantities in Wadi Natrun, and the latter is widely distributed in
limited quantities throughout the country, the main supply being however
obtained by evaporation from the shore lagoons along the coast of the
delta. Rock salt of fine quality occurs in many localities, notably in
the Eocene limestones three to four days east of Assiut.




APPENDICES


                TABLES                                             PAGES

  A.                I. Areas of the catchment basins of the Nile     119

  B.               II. Slopes of the Nile in its different reaches   120

  C.       III and IV. Velocities of the Nile in its different
                       reaches                                       121

  D.           V to X. Distances of places on the Nile from each
                       other                                         123

  E.       XI and XII. Details of observed discharges                129

  F.    XIII to XXIII. Observed discharges referred to gauges        131

  G.             XXIV. Mean discharges of the Nile tributaries in
                       1902, 1903 and 1904                           139

  H.              XXV. Maximum and minimum discharges in 1902 and
                       1903                                          141

  I.             XXVI. Monthly discharges at Khartoum, Assuân and
                       Cairo                                         142

  J.      XXVII to XL. Discharge tables for the different gauges on
                       the Nile                                      143

  K.       XLI to LII. Detailed information about the Nile, Assuân
                       to Cairo                                      153

  L.     LIII to LXIX. Gauges of the Nile and its tributaries        167

  M.     LXX and LXXI. Assuân and Cairo gauges, metres corresponding
                       to pics                                       209

  N. LXXII and LXXIII. Table converting cubic metres per day to cubic
                       metres per second and vice versa              211

  P.            LXXIV. Bombay rainfall referred to the Assuân gauge  213

  Q.    LXXV to LXXXI. Meteorological data in the Nile Valley        214

N.B.--In Appendix L, the gauges are recorded in two different methods.
If the fall or rise of water surface is gradual throughout the year, the
gauges are recorded in five daily intervals. If, on the other hand, the
rise and fall is gradual for the first four and last three months of the
year, but the changes are abrupt in the remaining five months, the
gauges are recorded in five daily intervals for seven months and daily
for five months.


Appendix A.


TABLE I.--_Areas of Catchment Basins of the Nile._

  =========================================+===========================
                 River.                    | AREA IN SQUARE KILOMETRES
                                           +-------+---------+---------
                                           | Area. |  Total. |  Grand
                                           |       |         |  Total.
  -----------------------------------------+-------+---------+---------
  Victoria Nile at Ripon Falls             |244,000|  244,000|   ...
  Additional area drained into Lake Albert |135,000|    ...  |   ...
  Albert Nile at outlet of Lake Albert     |  ...  |  379,000|   ...
  Albert Nile from Albert Lake to Gondokoro| 94,000|    ...  |   ...
  Albert Nile at Gondokoro                 |  ...  |  473,000|   ...
  Albert Nile, Gondokoro to above Sobat    |       |         |
  mouth                                    |202,000|    ...  |   ...
  Gazelle River                            |240,000|    ...  |   ...
  Arab River                               |231,000|    ...  |   ...
                                           +-------+         |
                                           |673,000|         |
                                           |       |         |
  Albert Nile above Sobat River mouth      |  ...  |1,136,000|   ...
  Saubat River                             |156,000|    ...  |   ...
  White Nile below Sobat River mouth       |  ...  |1,292,000|   ...
  White Nile, Sobat River to Khartoum      |393,000|    ...  |   ...
  White Nile at Khartoum                   |  ...  |1,685,000|1,685,000
  Blue Nile in Abyssinian Hills and foot   |       |         |
  hills                                    |247,000|    ...  |   ...
  Blue Nile foot hills to Khartoum         | 53,000|    ...  |   ...
                 Total Blue Nile           |  ...  |  300,000|   ...
                                           |       |         |
  Nile at Khartoum                         |  ...  |    ...  |1,985,000
  Nile between Khartoum and Atbara         |       |         |
  junction                                 | 54,000|    ...  |   ...
  Nile above Atbara junction               |  ...  |    ...  |2,049,000
  Atbara River in Abyssinian hills and foot|       |         |
  hills                                    |131,000|    ...  |   ...
  Atbara River foothills to mouth          |106,000|    ...  |   ...
                 Total Atbara River        |  ...  |  237,000|   ...
                                           |       |         |
  Nile below Atbara junction               |  ...  |    ...  |2,286,000
  Lybian Desert from Atbara junction       |       |         |
  to Sea                                   |335,000|    ...  |   ...
  Arabian Desert from Atbara junction      |       |         |
  to Sea                                   |386,000|    ...  |   ...
                 Total Desert Area         |  ...  |  721,000|   ...
                                           |       |         |
  Nile from its sources to its mouths      |  ...  |    ...  |3,007,000
                                           |       |         +---------
                                           |       |         |3,007,000
  =========================================+=======+=========+=========


Appendix B.


TABLE II.--_Slope of the Nile in flood from the Ripon Falls to the Sea._

  ===========+================+===============+========+=======+========
     River.  |    From        |     To        |Distance| Fall  | Slope.
             |                |               |   in   |  in   |
             |                |               |  kilo- |metres.|
             |                |               | mètres.|       |
  -----------+----------------+---------------+--------+-------+--------
  Victoria   |                |               |        |       |
  Nile       |Ripon Falls     |Kakoji         |    64  |   57  |¹⁄₁₂₀₀
       „     |Kakoji          |Fowera         |   237  |   12  |¹⁄₂₀₀₀₀
       „     |Fowera          |Murchison Falls|    68  |  377  |¹⁄₁₈₀
       „     |Murchison       |               |        |       |
             |Falls           |Lake Albert    |    30  |    3  |¹⁄₁₀₀₀₀
  Albert Nile|Lake Albert     |Dufile         |   218  |    8  |¹⁄₂₅₀₀₀
      „      |Dufile          |Fort Berkeley  |   155  |  223  |¹⁄₇₀₀
      „      |Fort Berkeley   |Bôr            |   206  |   18  |¹⁄₁₂₀₀₀
      „      |Bôr             |Gaba Shamba    |   196  |   10  |¹⁄₂₀₀₀₀
      „      |Gaba Shamba     |Lake Nô        |   380  |   16  |¹⁄₂₅₀₀₀
      „      |Lake Nô         |Sobat          |   134  |    2  |¹⁄₇₅₀₀₀
  White Nile |Sobat           |300 kilom.     |        |       |
             |                |South of       |        |       |
             |                |Khartum        |   538  |   11  |¹⁄₅₀₀₀₀
      „      |300 kilom.      |               |        |       |
             |South of        |               |        |       |
             |Khartum         |Khartum        |   300  |    3  |¹⁄₁₀₀₀₀₀
  The Nile.  |Khartum         |Shabluka       |    86  |    5  |¹⁄₁₇₀₀₀
             |                |6th Cataract   |    18  |    6  |¹⁄₃₀₀₀
      „      |6th Cataract    |5th Cataract   |   285  |   17  |¹⁄₁₇₀₀₀
             |                |       „       |   160  |   55  |¹⁄₃₀₀₀
      „      |5th Cataract    |4th Cataract   |    97  |    9  |¹⁄₁₁₀₀₀
             |                |       „       |   110  |   49  |¹⁄₂₂₅₀
      „      |4th Cataract    |3rd Cataract   |   313  |   26  |¹⁄₁₂₀₀₀
             |                |       „       |    80  |   11  |¹⁄₇₂₅₀
      „      |3rd Cataract    |2nd Cataract   |   110  |   17  |¹⁄₆₅₀₀
             |                |       „       |   200  |   66  |¹⁄₃₀₀₀
      „      |Wadi Haifa      |1st Cataract   |   345  |   28  |¹⁄₁₂₅₀₀
             |                |       „       |     5  |    6  |¹⁄₈₀₀
      „      |Assuân          |Barrage        |   964  |   75·4|¹⁄₁₃₀₀₀
      „      |Barrage         |Mediterranean  |        |       |
             |                |Sea            |   236  |   18·6|¹⁄₁₂₅₀₀
             |                |               +--------+-------+--------
             |                |               |  5535  | 1129  | ¹⁄₅₀₀₀
  ===========+================+===============+========+=======+========


Appendix C.


TABLE III.--_Velocity of the Nile in its different reaches._

  ============+===============+===============+========+==============+
      Name    |      From     |       To      |Distance|   VELOCITY   |
       of     |               |               |   in   |  IN METRES   |
     River.   |               |               | kilo-  |   PER SEC.   |
              |               |               | metres.+------+-------+
              |               |               |        |  in  |in low |
              |               |               |        |flood.|supply.|
  ------------+---------------+---------------+--------+------+-------+
  Victoria    |               |               |        |      |       |
       Nile.  |Ripon Falls    |Kakoji         |    64  | 1·2  |  1·2  |
       „      |Kakoji         |Lake Choga     |    47  |  ·7  |   ·6  |
              |               |               |        |      |       |
              |           Lake Choga          |    80  |  ..  |  ..   |
              |               |               |        |      |       |
       „      |Lake Choga     |Fowera         |   110  |  ·7  |   ·6  |
       „      |Fowera         |Murchison Falls|    68  | 1·2  |  1·2  |
       „      |Murchison Falls|Lake Albert    |    30  |  ·9  |   ·7  |
              |               |               |        |      |       |
              |           Lake Albert         |    10  |  ..  |  ..   |
              |               |               |        |      |       |
  Albert Nile.|Lake Albert    |Dufile         |   218  |  ·7  |   ·6  |
       „      |Dufile         |Fort Berkeley  |   155  |  ·9  |   ·7  |
       „      |Fort Berkeley  |Bôr            |   206  | 1·2  |   ·9  |
       „      |Bôr            |Gaba Shamba    |   196  |  ·9  |   ·7  |
       „      |Gaba Shamba    |Lake Nô        |   380  |  ·6  |   ·6  |
       „      |Lake Nô        |Sobat          |   134  |  ·35 |   ·35 |
   White Nile.|Sobat          |300 kil. South |        |      |       |
              |               |of Khartum.    |   538  |  ·6  |   ·35 |
       „      |300 kil. South |               |        |      |       |
              |of Khartum.    |Khartum        |   300  |  ·35 |   ·35 |
   The Nile.  |Khartum        |Shabluka       |    86  | 1·6  |   ·8  |
       „      |         6th Cataract          |    18  | 2·3  |   ·8  |
       „      |6th Cataract--5th Cataract     |   285  | 1·6  |   ·8  |
       „      |          5th Cataract         |   160  | 2·3  |  1·2  |
       „      |5th Cataract--4th Cataract     |    97  | 1·75 |   ·85 |
       „      |         4th Cataract          |   110  | 2·3  |  1·2  |
       „      |4th Cataract--3rd Cataract     |   313  | 1·75 |   ·85 |
       „      |         3rd Cataract          |    80  | 2·1  |  1·0  |
       „      |3rd Cataract--2nd Cataract     |   110  | 2·1  |  1·0  |
       „      |         2nd Cataract          |   200  | 2·3  |  1·2  |
       „      |Wady Haifa--1st Cataract       |   345  | 1·75 |   ·85 |
       „      |         1st Cataract          |     5  | 2·3  |  1·2  |
       „      |Assuân--Barrage                |   964  | 1·75 |   ·85 |
  Rosetta     |                               |        |      |       |
       Branch.| Barrage--Mediterranean Sea    |   236  | 1·75 |   ·85 |
  ============+===============================+========+======+=======+

  ============+===============+===============+========+==============+
      Name    |      From     |       To      |Distance|   VELOCITY   |
       of     |               |               |   in   |IN KILOMETRES |
     River.   |               |               | kilo-  |   PER DAY.   |
              |               |               | metres.+------+-------+
              |               |               |        |  in  |in low |
              |               |               |        |flood.|supply.|
  ------------+---------------+---------------+--------+------+-------+
  Victoria    |               |               |        |      |       |
       Nile.  |Ripon Falls    |Kakoji         |    64  |  100 |  100  |
       „      |Kakoji         |Lake Choga     |    47  |   60 |   50  |
              |               |               |        |      |       |
              |           Lake Choga          |    80  |   .. |   ..  |
              |               |               |        |      |       |
       „      |Lake Choga     |Fowera         |   110  |   60 |   50  |
       „      |Fowera         |Murchison Falls|    68  |  100 |  100  |
       „      |Murchison Falls|Lake Albert    |    30  |   80 |   60  |
              |               |               |        |      |       |
              |           Lake Albert         |    10  |   .. |   ..  |
              |               |               |        |      |       |
  Albert Nile.|Lake Albert    |Dufile         |   218  |   60 |   50  |
       „      |Dufile         |Fort Berkeley  |   155  |   80 |   60  |
       „      |Fort Berkeley  |Bôr            |   206  |  100 |   75  |
       „      |Bôr            |Gaba Shamba    |   196  |   80 |   60  |
       „      |Gaba Shamba    |Lake Nô        |   380  |   50 |   50  |
       „      |Lake Nô        |Sobat          |   134  |   30 |   30  |
   White Nile.|Sobat          |300 kil. South |        |      |       |
              |               |of Khartum.    |   538  |   50 |   30  |
       „      |300 kil. South |               |        |      |       |
              |of Khartum.    |Khartum        |   300  |   30 |   30  |
   The Nile.  |Khartum        |Shabluka       |    86  |  140 |   70  |
       „      |         6th Cataract          |    18  |  200 |  100  |
       „      |6th Cataract--5th Cataract     |   285  |  140 |   70  |
       „      |          5th Cataract         |   160  |  200 |  100  |
       „      |5th Cataract--4th Cataract     |    97  |  150 |   75  |
       „      |         4th Cataract          |   110  |  200 |  100  |
       „      |4th Cataract--3rd Cataract     |   313  |  150 |   75  |
       „      |         3rd Cataract          |    80  |  180 |   90  |
       „      |3rd Cataract--2nd Cataract     |   110  |  180 |   90  |
       „      |         2nd Cataract          |   200  |  200 |  100  |
       „      |Wady Haifa--1st Cataract       |   345  |  150 |   75  |
       „      |         1st Cataract          |     5  |  200 |  100  |
       „      |Assuân--Barrage                |   964  |  150 |   75  |
  Rosetta     |                               |        |      |       |
       Branch.| Barrage--Mediterranean Sea    |   236  |  150 |   75  |
  ============+===============================+========+======+=======+

  ============+===============+===============+========+================
      Name    |     From      |       To      |Distance| TIME IN WHICH
       of     |               |               |   in   |  THE WATER
     River.   |               |               | kilo-  |TRAVELS IN DAYS.
              |               |               | metres.+------+---------
              |               |               |        |  in  | in low
              |               |               |        |flood.| supply.
  ------------+---------------+---------------+--------+------+---------
  Victoria    |               |               |        |      |
       Nile.  |Ripon Falls    |Kakoji         |    64  |  ·7  |   ·7
       „      |Kakoji         |Lake Choga     |    47  |  ·8  |   ·9
              |               |               |        |      |
              |           Lake Choga          |    80  |  ..  |   ..
              |               |               |        |      |
       „      |Lake Choga     |Fowera         |   110  | 1·8  |  2·2
       „      |Fowera         |Murchison Falls|    68  |  ·7  |   ·7
       „      |Murchison Falls|Lake Albert    |    30  |  ·4  |   ·5
              |               |               |        |      |
              |           Lake Albert         |    10  |  ..  |   ..
              |               |               |        |      |
  Albert Nile.|Lake Albert    |Dufile         |   218  | 3·6  |  4·4
       „      |Dufile         |Fort Berkeley  |   155  | 1·9  |  2·6
       „      |Fort Berkeley  |Bôr            |   206  | 2·1  |  2·7
       „      |Bôr            |Gaba Shamba    |   196  | 2·4  |  3·2
       „      |Gaba Shamba    |Lake Nô        |   380  | 7·6  |  7·6
       „      |Lake Nô        |Sobat          |   134  | 4·5  |  4·5
   White Nile.|Sobat          |300 kil. South |        |      |
              |               |of Khartum.    |   538  |10·7  | 17·9
       „      |300 kil. South |               |        |      |
              |of Khartum.    |Khartum        |   300  |10·0  | 10·0
   The Nile.  |Khartum        |Shabluka       |    86  |  ·6  |  1·2
       „      |         6th Cataract          |    18  |  ·1  |   ·2
       „      |6th Cataract--5th Cataract     |   285  | 2·0  |  4·1
       „      |          5th Cataract         |   160  |  ·8  |  1·6
       „      |5th Cataract--4th Cataract     |    97  |  ·6  |  1·3
       „      |         4th Cataract          |   110  |  ·6  |  1·1
       „      |4th Cataract--3rd Cataract     |   313  | 2·1  |  4·2
       „      |         3rd Cataract          |    80  |  ·4  |   ·9
       „      |3rd Cataract--2nd Cataract     |   110  |  ·6  |  1·2
       „      |         2nd Cataract          |   200  | 1·0  |  2·0
       „      |Wady Haifa--1st Cataract       |   345  | 2·3  |  4·6
       „      |         1st Cataract          |     5  | 0·02 |  0·05
       „      |Assuân--Barrage                |   964  | 6·4  | 13·0
  Rosetta     |                               |        |      |
       Branch.| Barrage--Mediterranean Sea    |   236  | 1·6  |  2·2
  ============+===============================+========+======+=========


TABLE IV.--_Time water travels along the Nile._

  =============+===========+==================+===========
      From     |    To     |       DAYS       | Distance
               |           +------+-----------+    in
               |           |  in  |    in     |kilometres.
               |           |flood.|low supply.|
  -------------+-----------+------+-----------+-----------
  Lake Victoria|Lake Choga |   2  |     2     |    111
           Lake Choga      |  ..  |    ..     |     80
  Lake Choga   |Lake Albert|   3  |     3     |    209
           Lake Albert     |  ..  |    ..     |      9
  Lake Albert  |Gondokoro  |   6  |     7     |    403
  Gondokoro    |Sobat      |  16  |    18     |    885
  Sobat        |Khartum    |  21  |    28     |    838
  Khartum      |Assuan     |  11  |    22     |  1,804
  Assuan       |Cairo      |   6  |    12     |    945
  -------------+-----------+------+-----------+-----------
  Lake Albert  |Cairo      |  60  |    87     |  4,875
  =============+===========+======+===========+===========


Appendix D.

DISTANCE FROM THE SEA TO CAIRO, CAIRO TO ASSUAN, ASSUAN TO KHARTUM,
KHARTUM TO GONDOKORO AND GONDOKORO TO THE RIPON FALLS, AND BACK.


TABLES V AND VI.--_Distances in kilometres from the Barrage to the sea
down the Damietta and Rosetta branches, and vice-versa, measured on the
steamer track or Deep Channel in kilometres._

  ========================+========+========
     Name of Place.       |Distance|Distance
                          |  from  |  from
                          |Barrage.|  Sea.
  ------------------------+--------+--------
               =Damietta Branch.=
  Birshams                |   23   |   213
  Benha                   |   51   |   185
  Mitbera                 |   62   |   174
  Zifta                   |   88   |   148
  Samanûd                 |  124   |   112
  Mansurah                |  142   |    94
  Sherbin                 |  168   |    68
  Ras el Khalig (Station) |  182   |    54
  Mit Abu Ghaleb          |  194   |    42
  Faraskur                |  203   |    33
  Damietta                |  221   |    15
  Sea                     |  236   |     0
  ========================+========+========
     Name of Place.       |Distance|Distance
                          |  from  |  from
                          |Barrage.|  Sea.
  ------------------------+--------+--------
               =Rosetta Branch.=
  Ashmun                  |   23   |  213
  Geres                   |   31   |  205
  Khatatbeh               |   45   |  191
  Gizaï                   |   63   |  173
  Tenoub                  |   95   |  141
  Kafr Zayat              |  119   |  117
  Kuddabah                |  140   |   96
  Shibrakhit              |  154   |   82
  Dessouk                 |  168   |   68
  Fuah                    |  181   |   55
  Atfé                    |  184   |   52
  Rosetta                 |  221   |   15
  Sea                     |  236   |    0
  ========================+========+========


TABLE VII.--_Distances in kilometres from Barrage to Assuan and back in
kilometres measured on the steamer track or Deep Channel.--Upper-Egypt._

  ===========================+========+========+===========
         Name of Place.      |Distance|Distance|
                             |  from  |  from  |
                             |Barrage.| Assuan.|
  ---------------------------+--------+--------+-----------
  Barrage                    |     0  |  968   |
  Kasr El Nil (Bridge)--Cairo|    23  |  945   |
  Rodah gauge                |    27  |  941   |
  Badreshen                  |    46  |  922   |
  Aiyat                      |    73  |  895   |
  Wastah                     |   108  |  860   |
  Beni Suef                  |   143  |  825   |
  Maghagha                   |   199  |  769   |
  Minieh                     |   268  |  700   |
  Rodah                      |   308  |  660   |
  Derüt Escape               |   340  |  628   |
  Manfalut                   |   377  |  591   |
  Asyut                      |   420  |  548   |
  Sohag                      |   520  |  448   |
  Girga                      |   561  |  407   |
  Baliyana                   |   579  |  389   |
  Dishna                     |   665  |  303   |
  Kena                       |   685  |  283   |
  Luxor                      |   749  |  219   |
  Armant                     |   768  |  200   |
  Esna                       |   807  |  161   |
  Edfou                      |   859  |  109   |
  Gebel Silsila              |   898  |   70   |
  Kom Ombo                   |   925  |   43   |
  Assuan                     |   968  |    0   |
  ===========================+========+========+===========


TABLE VIII.--_Distances in kilometres from Assuân to Khartoum and back._

  ================+========+=========+===========
   Name of Place. |Distance|Distance |
                  |  from  |  from   |
                  | Assuan.|Khartoum.|
  ----------------+--------+---------+-----------
  Assuan (Shellal)|     0  |  1804   |
  Kalabsha        |    57  |  1747   |
  Dekka           |   109  |  1695   |
  Korosko         |   187  |  1617   |
  Der             |   209  |  1595   |
  Ibrim           |   229  |  1575   |
  Toski           |   251  |  1553   |
  Abu Simbel      |   283  |  1521   |
  Wadi Haifa      |   345  |  1459   |
  Kaibar          |   663  |  1141   |
  Hannek          |   735  |  1069   |
  Dongola         |   795  |  1009   |
  Abu Hamed       |  1255  |   549   |
  Berber          |  1460  |   344   |
  Atbara          |  1484  |   320   |
  Shendy          |  1621  |   183   |
  Shabluka        |  1700  |   104   |
  Khartoum        |  1804  |     0   |
  ================+========+=========+===========


TABLE IX.--_Distances in kilometres from Khartoum to Gondokoro and
back._

  ==============+=========+==========+===========
  Name of Place.|Distance | Distance |
                |  from   |   from   |
                |Khartoum.|Gondokoro.|
  --------------+---------+----------+-----------
  Khartoum      |     0   |   1723   |
  Duem          |   201   |   1522   |
  Abou Zeid     |   336   |   1387   |
  Gebelain      |   384   |   1339   |
  Kaka          |   639   |   1084   |
  Kodok         |   747   |    976   |
  Tewfikieh     |   830   |    893   |
  Sobat         |   838   |    885   |
  Mouth of Zeraf|   886   |    837   |
  Lake No       |   972   |    751   |
  Hillet Nuer   |  1177   |    546   |
  Sudd Block 15 |  1218   |    505   |
  Gaba Shambe   |  1352   |    371   |
  Bor           |  1548   |    175   |
  Lado          |  1711   |     12   |
  Gondokoro     |  1723   |      0   |
  ==============+=========+==========+===========


TABLE X.--_Distances in kilometres from Gondokoro to Ripon Falls and
back._

  ===============+==========+============+===========
                 | Distance |  Distance  |
  Name of Place. |   from   |    from    |
                 |Gondokoro.|Ripon Falls.|
  ---------------+----------+------------+-----------
  Gondokoro      |      0   |     803    |
  Fort Berkeley  |     31   |     772    |
  Dufile         |    186   |     617    |
  Wadelai        |    331   |     472    |
  Lake Albert    |    403   |     400    |
  Murchison Falls|    434   |     369    |
  Fowera         |    501   |     302    |
  Mruli          |    611   |     192    |
  Lake Choga     |    691   |     112    |
  Kakogi         |    739   |      64    |
  Ripon Falls    |    803   |       0    |
  ===============+==========+============+===========


TABLE XI.--_Distances from Khartoum to Rosaires and back along the Blue
Nile._

  ==============+=========+=========+===========
                | Distance| Distance|
  Name of Place.|   from  |   from  |
                |Khartoum.|Rosaires.|
  --------------+---------+---------+-----------
  Khartoum      |     0   |   615   |
  Kamlin        |    98   |   517   |
  Rufaa         |   151   |   464   |
  Abu-Haraz     |   188   |   427   |
  Rahad mouth   |   190   |   425   |
  Wad-Medani    |   198   |   417   |
  Dinder mouth  |   265   |   350   |
  Sennaar       |   343   |   272   |
  Karkoj        |   462   |   153   |
  Rosaires      |   615   |     0   |
  ==============+=========+=========+===========


Appendix E


TABLE XII.--_Details of observed discharges from Sir W. Garstin’s report
on the Basin of the Upper Nile._

  =============+===============+======+=======+======+========+=========
    River.     |  Locality.    |Gauge.| Date. | Area |Velocity|Discharge
               |               |      |       |  of  | metres |    m³
               |               |      |       | Sec- |  per   |   per
               |               |      |       | tion.| second.| second.
  -------------+---------------+------+-------+------+--------+---------
  Victoria Nile|Above Ripon    |      |       |      |        |
               |Falls          |  ·51 |22·1·03|2312·0|  0·237 |  548·0
               |Murchison Falls|   .. |20·3·03| 894·4|  0·65  |  577·0
               |               |      |       |      |        |
  _Uganda      |               |      |       |      |        |
  Streams_:    |               |      |       |      |        |
               |               |      |       |      |        |
  Ruizi        |      ..       |   .. | 6·2·03|   9·0|  1·22  |   11·0
  Nyam Gasha   |      ..       |   .. |16·2·03|   8·9|  0·55  |    4·9
  Lukoku       |      ..       |   .. |24·2·03|   5·4|  0·53  |    2·8
  Mbuku        |      ..       |   .. |25·2·03|   6·1|  1·16  |    7·1
  Hima         |      ..       |   .. |25·2·03|   1·1|  0·70  |    0·7
  Ruimi        |      ..       |   .. |26·2·03|   5·8|  0·74  |    4·3
  Mpangu       |      ..       |   .. |26·2·03|   3·0|  0·88  |    2·6
  Msisi        |      ..       |   .. | 9·3·03|   6·7|  0·40  |    2·7
  Ngusi        |      ..       |   .. |12·3·03|  12·5|  0·50  |    6·2
  Kagera       |      ..       |   .. |26·2·03| 412·0|  0·35  |  143·0
  Semliki      |Outlet of      |      |       |      |        |
               |Lake Edward    |   .. |18·2·03| 130·0|  0·70  |   90·0
    „          |Inlet of       |      |       |      |        |
               |Lake Albert    |   .. | 4·3·03| 121·0|  0·96  |  116·0
               |               |      |       |      |        |
  _Albert Nile |               |      |       |      |        |
  tributaries_:|               |      |       |      |        |
               |               |      |       |      |        |
  Umi          |      ..       |   .. |22·3·03|  15·1|  1·20  |   12·3
  Asua         |      ..       |   .. |28·3·03|  18·7|  0·58  |   10·8
  Kit          |      ..       |   .. |     ..|    ..|    ..  |      0
  Albert Nile  |Wadeiai        |  ·52 |22·3·03| 770·9|  0·84  |  646·0
      „        |Gondokoro      |  ·18 |28·3·01| 779·0|  0·73  |  566·0
      „        |    „          |  ·84 | 9·9·02|1033·0|  0·93  |  960·0
      „        |    „          |  ·50 | 1·4·03| 615·0|  1·07  |  641·0
      „        |    „          | 2·33 | 9·9·03|1347·0|  1·37  | 1847·0
      „        |    „          |  ·84 |14·5·04|    ..|    ..  | 1138·0
      „        |Mongalla       |      |       |      |        |
      „        |(north of      |      |       |      |        |
               |Gondokoro)     |   .. |14·9·03|1487·0|  1·44  | 2046·0
      „        |Bôr            |   .. |16·9·03| 770·0|  1·14  |  888·0
      „        | „             | 2·03 |12·5·04|    ..|    ..  |  813·0
      „        |North of Gaba- |   .. | 4·9·02| 498·0|  0·80  |  398·0
      „        |Shamba         |   .. |18·9·03| 669·0|  0·80  |  532·0
      „        |Hillet Nûr     |   .. | 1·9·03| 478·0|  0·78  |  375·0
      „        |    „          |   .. |13·4·03| 392·0|  0·88  |  346·0
      „        |North of       |      |       |      |        |
               |Hillet-Nûr     |   .. | 1·4·01| 485·0|  0·54  |  262·0
      „        |    „          |   .. | 2·9·02| 511·0|  0·65  |  333·0
      „        |South of Lake  |      |       |      |        |
               |Nô             |   .. |14·4·00| 262·0|  0·84  |  219·0
      „        |    „          |   .. |14·4·03| 424·0|  0·71  |  285·0
      „        |    „          |   .. |31·8·03| 441·0|  0·72  |  318·0
      „        |    „          |   .. |22·5·04|    ..|    ..  |  302·0
  Bahr El Gazal|28 kil. from   |      |       |      |        |
               |mouth          |   .. |30·8·03|  52·0|  0·23  |   12·0
      „        |32  „          |   .. |21·9·03| 104·0|  0·19  |   20·0
      „        |33  „          |   .. | 2·4·01| 149·0|  0·18  |   27·0
      „        |33  „          |   .. |31·8·02|  86·0|  0·17  |   15·0
      „        |50  „          |   .. |15·4·03| 200·0|  0·20  |   23·0
      „        |51  „          |   .. | 1·4·00| 161·0|  0·21  |   34·0
  Bahr El Zeraf|8   „          |   .. |22·9·02| 240·0|  0·40  |   97·0
      „        |14  „          |   .. |29·8·03| 180·0|  0·61  |  110·0
      „        |19  „          |   .. | 3·4·01| 138·0|  0·24  |   33·0
      „        |20  „          |   .. |16·4·03| 179·0|  0·30  |   50·0
      „        |20  „          |   .. |22·9·03| 232·0|  0·66  |  158·0
      „        |96  „          |   .. |25·3·00|  91·0|  0·35  |   32·0
  Albert Nile  |Above Sobat    |      |       |      |        |
               |junction       |   .. |30·8·02| 813·0|  0·41  |  336·0
      „        |    „          |   .. |22·9·02|1054·0|  0·40  |  419·0
      „        |    „          |   .. |22·9·03|1034·0|  0·44  |  450·0
      „        |    „          |   .. |16·4·03| 710·0|  0·49  |  349·0
  Sobat River  |25 kil. from   |      |       |      |        |
               |mouth          | 3·16 |26·9·03|1030·0|  0·87  |  895·0
      „        |25  „          | 2·70 |26·8·03|    ..|    ..  |  769·0
      „        |40  „          |  ·10 |17·4·03| 414·0|  0·12  |   45·0
      „        |45  „          |   .. | 6·4·01| 401·0|  0·22  |   87·0
  White Nile   |Tewfikia       |   .. | 6·4·01|1081·0|  0·28  |  381·0
      „        |    „          |  ·24 |17·4·03|1068·0|  0·35  |  368·0
      „        |    „          | 2·65 |26·8·03|2174·0|  0·54  | 1046·0
      „        |    „          | 3·38 |26·9·03|2332·0|  0·56  | 1304·0
      „        |    „          |   .. |25·9·02|1983·0|  0·66  | 1272·0
  Blue Nile    |Outlet of Lake |      |       |      |        |
               |Tsana          |   .. |31·1·03|  65·0|  0·64  |   41·8
  =============+===============+======+=======+======+========+=========


Appendix F.


TABLE XIII.--_Observed discharges of the Victoria Nile referred to the
Jinja gauge on Lake Victoria._

1903

  ==========+===============+================================+===========
   Date of  |   Locality    |         GAUGE AT JINJA         | Discharge
  Discharge.| where taken.  |----------+----------+----------+in metres³
            |               |    Day   | 10 days  | 15 days  |per second.
            |               |    of    |  before  |  before  |
            |               |discharge.|discharge.|discharge.|
  ----------+---------------+----------+----------+----------+-----------
  22 January|Ripon Falls    |    ·51   |    ..    |    ..    |    548
   20 March |Below the      |          |          |          |
            |Murchison Falls|    ..    |   ·66    |   ·70    |    577
  ==========+===============+==========+==========+==========+===========


TABLE XIV.--_Observed discharges of the Albert Nile at Wadelai referred
to the Wadelai gauge._

1903

  ==========+======+===========+========
   Date of  |Gauge.| Discharge |Remarks.
  Discharge.|      |in metres³ |
            |      |per second.|
  ----------+------+-----------+--------
   22 March | ·52  |    646    |
  ==========+======+===========+========


TABLE XV.--_Observed discharges of the Albert Nile referred to the
Mongalla gauge._

                                    1903
  ======+======+========+==========================================+=======
  Loca- |Kilo- |  Date. |    MONGALLA GAUGE (32 kilom. north of    |  Dis-
  lity. |metres|        |                 Gondokoro)               |charge
        | from |        +-----+-----+-----+-----+-----+-------+----+ m³ per
        |Gondo-|        | 5   | 4   |  3  |  2  |  1  |  day  |  1 |second.
        |koro. |        |days |days | days| days| day |  of   | day|
        |      |        | be- | be- | be- | be- | be- | dis-  | af-|
        |      |        |fore.|fore.|fore.|fore.|fore.|charge.|ter.|
  ------+------+--------+-----+-----+-----+-----+-----+-------+----+-------
  Gondo-|    0 | 1 April|   ..|   ..|   ..|   ..|   ..| 0·83  |0·83|  693
  koro  |      |        |     |     |     |     |     |       |    |  [9]
        |      | 9 Sep- | 2·73| 2·85| 2·90| 3·02| 3·16| 3·14  |3·08| 1985
        |      |tember  |     |     |     |     |     |       |    | [10]
  Mon-  |   32 |14 Sep- | 3·14| 3·08| 2·90| 2·84| 2·82| 2·82  |2·82| 2046
  galla |      |tember  |     |     |     |     |     |       |    |
  Der-  |  156 |16 Sep- | 2·90| 2·84| 2·82| 2·82| 2·82| 2·84  |2·92|  888
  wish  |      |tember  |     |     |     |     |     |       |    |
  Dem   |      |        |     |     |     |     |     |       |    |
  North |  415 |18 Sep- | 2·82| 2·82| 2·82| 2·84| 2·92| 3·06  |3·12|  532
  of    |      |tember  |     |     |     |     |     |       |    |
  Gaba- |      |        |     |     |     |     |     |       |    |
  Shamba|      |        |     |     |     |     |     |       |    |
  Hillet|  538 | 1 Sep- | 2·52| 2·52|  ?  |  ?  |  ?  | 2·52  |2·45|  375
  Nur   |      |tember  |     |     |     |     |     |       |    |
  Hillet|  542 |13 April| 0·87| 0·89| 0·90| 0·90| 0·87| 0·88  |0·88|  331
  Nur   |      |        |     |     |     |     |     |       |    |
  South |  741 |14 April| 0·89| 0·90| 0·90| 0·87| 0·88| 0·88  |0·89|  285
  of    |      |        |     |     |     |     |     |       |    |
  Lake  |      |        |     |     |     |     |     |       |    |
  No    |      |        |     |     |     |     |     |       |    |
  South |  742 |31 Au-  | 2·49| 2·52| 2·52|  ?  |  ?  |  ?    |2·52|  318
  of    |      |gust    |     |     |     |     |     |       |    |
  Lake  |      |        |     |     |     |     |     |       |    |
  No    |      |        |     |     |     |     |     |       |    |
                                    1904
  Gondo-|      |14 May  | 1·89| 1·89| 1·96| 2·03| 2·10| 2·03  |2·07| 1138
  koro  |      |        |     |     |     |     |     |       |    |
  Bôr   |  165 |12 May  | 1·89| 1·89| 1·89| 1·89| 1·96| 2·03  |2·10|  813
  South |  742 |22 May  | 2·03| 2·03| 2·03| 2·07| 2·07| 2·17  |2·17|  302
  of    |      |        |     |     |     |     |     |       |    |
  Lake  |      |        |     |     |     |     |     |       |    |
  No    |      |        |     |     |     |     |     |       |    |

  [9] 641 + 52 for side channel.

  [10] 1847 + 138 for side channel.


TABLE XVI.--_Observed discharges of the Bahr El Gazelle referred to the
Tewfikia gauge on the White Nile._

  ============+===========================+=======+===========
     Date     |           GAUGE           |  Dis- |  Remarks.
      of      +------+------+------+------+charges|
   discharge. | Day. |   1  |   2  |   3  |  m³   |
              |      |  day | days | days | per   |
              |      |after.|after.|after.|second.|
  ------------+------+------+------+------+-------+-----------
  21 September| 3·31 | 3·33 | 3·35 | 3·36 |  20   |
  30 August   | 2·74 | 2·75 | 2·76 | 2·77 |  12   |
  ============+======+======+======+======+=======+===========


TABLE XVII.--_Observed discharges of the Bahr El Zeraf referred to the
Tewfikia gauge on the White Nile._

                                  1903
  ==============+==============================+===========+==========
      Date      |             GAUGE            |Discharge  | Remarks.
  of discharge. +-----------+-------+----------+    m³     |
                |      1    |  Day. |    1     |per second.|
                |day before.|       |day after.|           |
  --------------+-----------+-------+----------+-----------+----------
  16 April      |    0·24   | 0·24  |   0·24   |    50     |
  22 September  |    3·31   | 3·33  |   3·35   |   158     |
   8 May        |    0·25   | 0·26  |   0·26   |    61     |
  29 August     |    2·68   | 2·70  |   2·72   |   110     |App. gauge
                                  1904
  23 May        |    1·35   | 1·38  |   1·40   |   124     |
  ==============+===========+=======+==========+===========+==========


TABLE XVIII.--_Observed discharges of the Albert Nile above the Sobat
junction referred to the Tewfikia gauge._

                              1903
  =============+=================================+===========
     Date      |              GAUGE              |Discharge
  of discharge.+-----------+----------+----------+   m³
               |    1      |   day.   |     1    |per second.
               |day before.|          |day after.|
  -------------+-----------+----------+----------+-----------
  16 April     |    ·24    |    ·24   |    ·24   |   349
  22 September |   3·31    |   3·33   |   3·35   |   450
  =============+===========+==========+==========+===========


TABLE XIX.--_Observed discharges of the Sobat River referred to the
Dulaib Hilla gauge._

                              1903
  =============+===========+==========+==========+===========
  17 April     |     ..    |    ·10   |     ..   |    45
  26 August    |   2·70    |   2·71   |   2·74   |   769
  26 September |   3·16    |   3·17   |   3·19   |   895
  =============+===========+==========+==========+===========


TABLE XX.--_Observed discharges of the White Nile just below the Sobat
junction referred to the Tewfikia gauge._

                              1903
  =============+===========+=========+==========+============
  17 April     |    ·24    |    ·24  |    ·24   |    381
  26 August    |   2·64    |   2·65  |   2·66   |   1046
  26 September |   3·37    |   3·38  |   3·40   |   1304
  =============+===========+=========+==========+============


TABLE XXI.--_Observed discharges of the White Nile at Duem referred to
the Duem and Khartoum gauges._

  ===========+======+==================================+=========
     Date.   | Duem |          KHARTOUM GAUGES         |Discharge
             |Gauge |                                  |  cubic
             |  -   +-------+-------+-------+----------+ metres
             |Gauge.|3 days |2 days | day   | day of   |   per
             |      |before.|before.|before.|discharge.| second.
  -----------+------+-------+-------+-------+----------+---------
             |      |       |       |       |          |
      1902   |      |       |       |       |          |
             |      |       |       |       |          |
  May 13     |  ·51 |  -·06 |  -·07 |  -·04 |   -·04   |  347
  June 11    |  ·95 |   ·76 |   ·75 |   ·77 |    ·84   |  650
  July 8     | 1·42 |  1·70 |  1·70 |  1·85 |   2·03   |  788
  August 5   | 2·20 |  3·52 |  3·62 |  3·71 |   3·79   |  867
  September 2| 3·48 |  5·30 |  5·30 |  5·20 |   5·20   |  330
  October 1  | 3·50 |  5·03 |  5·06 |  5·16 |   5·14   |  870
  October 28 | 2·50 |  3·35 |  3·30 |  3·23 |   3·16   |  802
  December 1 | 2·00 |  2·11 |  2·10 |  2·08 |   2·06   |  930
  December 29| 2·04 |  1·54 |  1·50 |  1·48 |   1·45   | 1518
             |      |       |       |       |          |
      1903   |      |       |       |       |          |
             |      |       |       |       |          |
  January 27 | 1·12 |  0·90 |  0·87 |  0·84 |   0·83   |  663
  February 24| 0·86 |  0·36 |  0·32 |  0·29 |   0·28   |  462
  March 24   | 0·46 |  0·02 |  0·01 |  0·01 |   0·02   |  559
  April 21   | 0·38 | -0·14 | -0·12 | -0·12 |  -0·16   |  415
  May 19     | 0·38 | -0·26 | -0·23 | -0·21 |  -0·19   |  447
  June 16    | 1·09 |  1·41 |  1·56 |  1·65 |   1·75   |  658
  July 1     | 1·31 |  1·61 |  1·54 |  1·54 |   1·54   |  884
   „  14     | 1·71 |  2·55 |  2·58 |  2·75 |   2·80   |  835
  August 4   | 2·46 |  3·50 |  3·80 |  4·05 |   4·40   |  768
   „  11     | 3·28 |  4·95 |  5·06 |  5·06 |   5·10   |  579
   „  18     | 3·70 |  5·55 |  5·70 |  5·80 |   5·70   |  534
   „  23     | 4·08 |  5·80 |  5·90 |  5·95 |   6·00   |  654
   „  28     | 4·18 |  6·03 |  6·08 |  6·00 |   6·05   |  710
  September 2| 4·33 |  6·15 |  6·28 |  6·24 |   6·30   |  571
   „   7     | 4·43 |  6·20 |  6·20 |  6·15 |   6·12   |  737
   „  12     | 4·46 |  6·24 |  6·14 |  6·15 |   6·05   |  653
   „  18     | 4·40 |  5·86 |  5·95 |  5·88 |   5·88   |  840
   „  24     | 4·28 |  5·95 |  6·00 |  6·10 |   6·10   |  763
  October  7 | 3·93 |  5·57 |  5·40 |  5·32 |   5·10   | 1588
  November 3 | 3·11 |  3·90 |  3·85 |  3·75 |   3·65   | 1563
   „  24     | 2·44 |  2·65 |  2·63 |  2·63 |   2·60   | 1665
  December 8 | 2·06 |  2·30 |  2·28 |  2·20 |   2·15   | 1462
   „  22     | 1·80 |  1·90 |  1·90 |  1·88 |   1·88   | 1403
             |      |       |       |       |          |
      1904   |      |       |       |       |          |
             |      |       |       |       |          |
  January 6  | 1·66 |  1·78 |  1·78 |  1·78 |   1·75   | 1508
  „   20     | 1·54 |  1·48 |  1·48 |  1·48 |   1·55   | 1466
  ===========+======+=======+=======+=======+==========+=========


TABLE XXII.--_Observed discharges of the Blue Nile at Khartoum referred
to the Wad-Medani and Khartoum gauges._

                                  1902
  ============+==========================+=======+=========+=========
      Date    |     WAD MEDANI GAUGES    | Dis-  |         |
       of     +-------+-------+----------+charge |         |
   Discharge. |  2    |  1    |  Date    |m³ per | Khartoum| Remarks.
              | days  | day   |   of     |second.|  gauges.|
              |before.|before.|discharge.|       |         |
  ------------+-------+-------+----------+-------+---------+---------
   9 May      |   ·39 |   ·39 |    ·37   |  184  |  -0·05  |
  23  „       |   ·71 |   ·61 |    ·65   |  194  |   0·16  |
   6 June     |  2·07 |  2·03 |   1·97   |  604  |   0·76  |
  20  „       |  2·97 |  3·27 |   3·39   |  695  |   1·06  |
  27  „       |  3·04 |  3·89 |   4·29   |  837  |   1·30  |
   4 July     |  3·80 |  3·70 |   3·80   | 1032  |   1·75  |
  11  „       |  4·56 |  4·38 |   4·48   | 1453  |   2·07  |
  18  „       |  4·80 |  5·10 |   5·20   | 1612  |   2·33  |
  25  „       |  5·70 |  5·66 |   5·76   | 1885  |   2·64  |
   1 August   |  7·06 |  7·28 |   7·56   | 3420  |   3·34  |
   8   „      |  8·56 |  8·76 |   8·86   | 4880  |   4·20  |
  15   „      |  9·14 |  9·02 |   8·96   | 4720  |   4·50  |
  22   „      | 10·08 | 10·00 |   9·66   | 5540  |   4·93  |
  29   „      | 10·46 | 10·52 |  10·32   | 7180  |   5·34  |
   5 September| 10·42 | 10·32 |  10·30   | 6580  |   5·27  |
  12    „     | 10·40 | 10·28 |  10·60   | 5800  |   5·35  |
  19    „     | 10·32 | 10·00 |  10·30   | 5760  |   5·30  |
  26    „     | 10·00 | 10·10 |   9·90   | 4800  |   5·10  |
   3 October  |  9·94 |  9·88 |   9·70   | 4880  |   5·03  |
  10   „      |  8·40 |  8·20 |   8·00   | 3250  |   3·45  |
  17   „      |  7·38 |  7·48 |   7·40   | 2460  |   3·73  |
  24   „      |  6·94 |  6·88 |   6·78   | 2030  |   3·40  |
  31   „      |  6·18 |  6·14 |   6·04   | 1244  |   3·00  |
   7 November |  5·66 |  5·60 |   5·50   | 1272  |   2·77  |
  14    „     |  5·10 |  5·06 |   5·00   | 1035  |   2·48  |
  21    „     |  4·74 |  4·74 |   4·70   |  802  |   2·23  |
  28    „     |  4·56 |  4·54 |   4·46   |  787  |   2·11  |
   5 December |  4·08 |  4·04 |   4·00   |  654  |   1·94  |
  12    „     |  3·73 |  3·74 |   3·66   |  486  |   1·80  |
  23    „     |  3·43 |  3·32 |   3·26   |  476  |   1·58  |
                                  1903
   2 January  |  2·90 |  2·88 |   2·84   |  348  |   1·39  |
   9    „     |  2·64 |  2·60 |   2·58   |  270  |   1·22  |
  16    „     |  2·48 |  2·46 |   2·44   |  248  |   1·09  |
  23    „     |  2·34 |  2·32 |   2·30   |  250  |   0·94  |
   6 February |  2·06 |  2·04 |   2·04   |  226  |   0·60  |
  20    „     |  1·86 |  1·84 |   1·84   |  152  |   0·39  |
   6 March    |  1·60 |  1·60 |   1·58   |  202  |   0·18  |
  20   „      |  1·36 |  1·34 |   1·34   |  201  |   0·04  |
   3 April    |  1·24 |  1·20 |   1·20   |  132  |[=0]·12  |
  17   „      |  1·08 |  1·04 |   1·04   |  154  |[=0]·16  |
   1 May      |  0·98 |  0·98 |   0·96   |  121  |[=0]·16  |
   8  „       |  0·88 |  0·88 |   0·90   |  Nil  |[=0]·23  |
  15  „       |  0·88 |  0·92 |   0·98   |   „   |[=0]·26  |
  22  „       |  1·40 |  1·66 |   1·70   |   „   |[=0]·09  |
  28  „       |  2·74 |  1·51 |   3·43   |  374  |   0·53  |
   6 June     |  4·05 |  3·61 |   3·65   |  970  |   1·40  |
  19  „       |  4·70 |  4·62 |   4·52   | 1500  |   1·90  |
  26  „       |  4·25 |  4·51 |   4·31   | 1089  |   1·58  |
   3 July     |  4·71 |  5·27 |   5·61   | 1314  |   1·78  |
  10  „       |  6·45 |  6·55 |   6·67   | 1952  |   2·48  |
  17  „       |  6·74 |  6·57 |   6·91   | 2267  |   2·75  |
  24  „       |  7·97 |  7·81 |   7·87   | 3183  |   3·40  |
  31  „       |  7·77 |  7·67 |   7·70   | 2870  |   3·45  |
   5 August   |  9·81 | 10·11 |  10·11   | 7584  |   4·60  |
  10   „      | 10·15 |  9·99 |   9·89   | 7100  |   5·06  |
  14   „      | 10·59 | 10·71 |  10·57   | 9340  |   5·65  |
  21   „      | 10·49 | 10·73 |  10·71   | 9519  |   5·90  |
  28   „      | 10·47 | 10·41 |  10·61   | 9544  |      ?  |
   4 September| 10·68 | 10·44 |  10·40   | 8474  |   6·20  |
  11    „     | 10·74 | 10·52 |  10·46   | 8385  |   6·15  |
  18    „     |  9·94 |  9·92 |   9·96   | 7070  |   5·88  |
  25    „     | 10·52 | 10·46 |  10·32   | 8965  |   6·08  |
   2 October  |  9·22 |  9·48 |   9·36   | 6581  |   5·53  |
   9   „      |  9·14 |  9·04 |   8·64   | 5749  |   5·15  |
  16   „      |  7·97 |  7·94 |   8·07   | 3812  |   4·45  |
  23   „      |  8·90 |  8·64 |   8·54   | 4198  |   4·56  |
  30   „      |  7·53 |  7·33 |   7·29   | 2893  |   4·00  |
   6 November |  6·86 |  6·68 |   6·32   | 2275  |   3·50  |
  13    „     |  6·00 |  5·90 |   5·70   | 1790  |   3·10  |
  20    „     |  5·71 |  5·65 |   5·55   | 1456  |   2·65  |
   4 December |  4·90 |  4·88 |   4·84   | 1102  |   2·35  |
  18    „     |  4·36 |  4·30 |   4·28   |  789  |   1·90  |
  25    „     |  3·90 |  3·88 |   3·84   |  722  |   1·88  |
                                  1904
   1 January  |  3·60 |  3·66 |   3·64   |  604  |   1·80  |
  15    „     |  3·40 |  3·38 |   3·36   |  488  |   1·59  |
  ============+=======+=======+==========+=======+=========+=========


TABLE XXIII.--_Observed discharges of the Atbara referred to the Khasm
El Girba gauge._

                                 1903
  ============+=====================================+=======+=======
    Date of   |                 GAUGES              | Dis-  |REMARKS
   Discharge. +-----+-----+-----+-----+-----+-------+charge |
              |  5  |  4  |  3  |   2 |  1  |  Date |  m³   |
              |days |days |days | days| day |   of  | per   |
              | be- | be- | be- |  be-| be- | dis-  |second.|
              |fore.|fore.|fore.|fore.|fore.|charge.|       |
  ------------+-----+-----+-----+-----+-----+-------+-------+-------
  16 July     | 2·65| 2·31| 2·10| 2·10| 2·65|  2·28 |   381 |
  23   „      | 2·37| 2·55| 2·74| 2·83| 2·70|  2·70 |   538 |
  27   „      | 2·70| 2·70| 3·00| 2·62| 2·53|  2·60 |   780 |
   2 August   | 2·76| 2·80| 3·29| 3·54| 4·21|  4·00 |   758 |
   5   „      | 3·54| 4·21| 4·00| 3·56| 3·25|  3·35 |  1448 |
  14   „      | 3·29| 3·72| 4·61| 4·37| 4·53|  4·60 |  2318 |
  15   „      | 3·72| 4·61| 4·37| 4·53| 4·60|  4·85 |  2931 |
  27   „      | 5·12| 4·82| 4·54| 4·35| 4·20|  4·80 |  2632 |
  30   „      | 4·35| 4·20| 4·80| 4·55| 4·55|  4·75 |  3088 |
   5 September| 4·45| 4·52| 4·52| 4·60| 4·70|  4·55 |  2822 |
  12    „     | 4·58| 4·50| 4·15| 4·30| 3·89|  3·95 |  2091 |
  18    „     | 3·80| 3·84| 3·71| 3·88| 4·36|  4·20 |  1672 |
  25    „     | 4·12| 3·80| 4·45| 3·30| 3·25|  3·10 |  1267 |
  28    „     | 3·30| 3·25| 3·10| 2·89| 3·42|  3·10 |   902 |
   2 October  | 3·42| 3·10| 3·13| 3·05| 2·88|  2·78 |   925 |
   4    „     | 3·13| 3·05| 2·88| 2·78| 2·78|  2·90 |   754 |
   5    „     | 3·05| 2·88| 2·78| 2·78| 2·90|  2·75 |   703 |
  ============+=====+=====+=====+=====+=====+=======+=======+=======


Appendix G.

TABLES GIVING MEAN MONTHLY DISCHARGES OF THE NILE AND ITS TRIBUTARIES
DURING 1902, 1903 AND 1904.

TABLE XXIV.--_Mean discharges of the Nile tributaries in cubic metres
per second at the various gauge stations in 1902, 1903, 1904._

                                  1902
  =========+=======+====================+=====+======+=====+========+
    Month. | Victo-|    ALBERT NILE     | Ga- |Sobat |White|  White |
           |  ria  +-----+------+-------+zelle|river.| Nile|  Nile  |
           |Nile at|Wade-|Gondo-| Above |river|      |  at |   at   |
           | Ripon |lai. | koro.| Sobat | app.|      | Tew-|  Khar- |
           | Falls.|     |      | junc- |     |      | fi- |  toum. |
           |       |     |      | tion. |     |      | kia.|        |
           |       |     |      |       |     |      |     |        |
  ---------+-------+-----+------+-------+-----+------+-----+--------+
  January  |  510  |  620|  660 | ..    |  .. |   .. |   ..| 950    |
  February |  510  |  580|  640 | ..    |  .. |   .. |   ..| 550    |
  March    |  500  |  570|  660 | ..    |  .. |   .. |   ..| 420    |
  April    |  530  |  540|  550 | ..    |  .. |   .. |   ..| 370    |
  May      |  560  |  560|  630 | ..    |  .. |   .. |   ..| 350    |
  June     |  550  |  550|  550 | ..    |  .. |   .. |   ..| 600    |
  ---------+-------+-----+------+-------+-----+------+-----+--------+
  July     |  530  |  560|  600 | ..    |  .. |   .. |   ..| 900    |
  August   |  520  |  580| 1000 |340    |  .. |  570 |  910| 600[11]|
  September|  510  |  610|  820 |420    |  .. |  810 | 1230| 600[11]|
  October  |  490  |  640|  780 | ..    |  .. |   .. |   ..| 900    |
  November |  500  |  710|  900 | ..    |  .. |   .. |   ..| 850    |
  December |  490  |  740|  860 | ..    |  .. |   .. |   ..|1202    |
           +-------+-----+------+-------+-----+------+-----+--------+
  Year     |  520  |  600|  720 | ..    |  .. |   .. |   ..| 690    |
  ---------+-------+-----+------+-------+-----+------+-----+--------+
                                  1903
  =========+=======+=====+======+=======+=====+======+=====+========+
  January  |  530  |  710|  760 |400    |   0 |  600 | 1000|1000    |
  February |  610  |  680|  740 |370    |   0 |  230 |  600| 600    |
  March    |  630  |  660|  700 |350    |   0 |  130 |  480| 500    |
  April    |  650  |  640|  700 |360    |   0 |   40 |  400| 420    |
  May      |  740  |  670|  900 |390    |   0 |  100 |  490| 420    |
  June     |  800  |  710| 1020 |400    |   0 |  320 |  720| 600    |
           +-------+-----+------+-------+-----+------+-----+--------+
  July     |  840  |  760| 1100 |410    |  10 |  410 |  820| 700[11]|
  August   |  790  |  820| 1600 |420    |  10 |  680 | 1100| 400[11]|
  September|  730  |  870| 2100 |430    |  20 |  870 | 1300| 600[11]|
  October  |  770  |  970| 1900 |360    |  30 | 1040 | 1400|1700    |
  November |  810  | 1040| 1700 |350    |  30 | 1080 | 1430|1600    |
  December |  810  | 1060| 1200 |380    |  30 | 1080 | 1460|1450    |
           +-------+-----+------+-------+-----+------+-----+--------+
  Year     |  730  |  800| 1200 |390    |  10 |  550 |  940| 830    |
  ---------+-------+-----+------+-------+-----+------+-----+--------+
                                  1904
  =========+=======+=====+======+=======+=====+======+=====+========+
  January  |   ..  | 1060| 1100 |460    |  30 |  770 | 1230|1200    |
  February |   ..  | 1030| 1060 |430    |  20 |  230 |  660| 800    |
  March    |   ..  | 1000| 1020 |430    |  20 |  130 |  560| 520    |
  April    |   ..  | 1000| 1060 |430    |  10 |  100 |  530| 500    |
  May      |   ..  |   ..| 1200 |430    |   0 |  160 |  590| 500    |
  June     |   ..  |   ..| 1200 |400[11]|   0 |  290 |  690| 550    |
           +-------+-----+------+-------+-----+------+-----+--------+
  July     |   ..  |   ..|   .. | ..    |  .. |   .. |   ..|  ..    |
  August   |   ..  |   ..|   .. | ..    |  .. |   .. |   ..|  ..    |
  September|   ..  |   ..|   .. | ..    |  .. |   .. |   ..|  ..    |
  October  |   ..  |   ..|   .. | ..    |  .. |   .. |   ..|  ..    |
  November |   ..  |   ..|   .. | ..    |  .. |   .. |   ..|  ..    |
  December |   ..  |   ..|   .. | ..    |  .. |   .. |   ..|  ..    |
           +-------+-----+------+-------+-----+------+-----+--------+
  Year     |   ..  |   ..|   .. | ..    |  .. |   .. |   ..|  ..    |
  =========+=======+=====+======+=======+=====+======+=====+========+

                              1902
  =========+=====+======+=======+============+=======+========
    Month. | Blue|Atbara| Total |  Nile at:  |Rosetta|Damietta
           | Nile|river.|  for: |  Halfa =   |branch.| branch.
           |  at |      | White,|1^{st} Jan.-|       |
           |Khar-|      |  Blue |1^{st} July.|       |
           |toum.|      |  and  |  Assuân =  |       |
           |     |      | Atbara|1^{st} July-|       |
           |     |      |rivers.|1^{st} Jan. |       |
  ---------+-----+------+-------+------------+-------+--------
  January  |  280|    0 |  1230 |    1100    |  1000 |    20
  February |  240|    0 |   790 |     720    |   290 |    40
  March    |  190|    0 |   610 |     600    |    40 |    40
  April    |  190|    0 |   560 |     530    |     0 |     0
  May      |  180|    0 |   530 |     510    |     0 |     0
  June     |  600|   50 |  1250 |     550    |     0 |     0
  ---------+-----+------+-------+------------+-------+--------
  July     | 1500|  500 |  2900 |    1100    |     0 |     0
  August   | 5000| 1200 |  6300 |    3600    |   800 |   400
  September| 6200| 1200 |  8000 |    6600    |  2600 |   400
  October  | 2800|   80 |  3780 |    4950    |  2500 |  1300
  November | 1000|    0 |  1850 |    2400    |  1400 |   700
  December |  500|    0 |  1700 |    1700    |  1600 |   140
           +-----+------+-------+------------+-------+--------
  Year     | 1560|  250 |  2500 |    2030    |   850 |   340
  ---------+-----+------+-------+------------+-------+--------
                              1903
  =========+=====+======+=======+============+=======+========
  January  |  300|    0 |  1300 |    1300    |  1300 |    20
  February |  240|    0 |   840 |     880    |   500 |    20
  March    |  180|    0 |   680 |     620    |   100 |    30
  April    |  120|    0 |   540 |     480    |     0 |     0
  May      |  280|    0 |   700 |     440    |     0 |     0
  June     | 1200|  200 |  2000 |     630    |     0 |     0
           +-----+------+-------+------------+-------+--------
  July     | 2500|  600 |  3800 |    1400    |     0 |   150
  August   | 8200| 2300 | 10900 |    5700    |  1500 |   300
  September| 8200| 1500 | 10300 |    8600    |  3300 |  2000
  October  | 4500|    0 |  6200 |    6300    |  3500 |  2200
  November | 1700|    0 |  3200 |    3400    |  2500 |  1600
  December |  800|    0 |  2253 |    2000    |  1100 |   800
           +-----+------+-------+------------+-------+--------
  Year     | 2350|  380 |  3560 |    2650    |  1150 |   590
  ---------+-----+------+-------+------------+-------+--------
                              1904
  =========+=====+======+=======+============+=======+========
  January  |  500|    0 |  1700 |    1400    |  1000 |   580
  February |  300|    0 |  1100 |    1300    |   850 |   110
  March    |  210|    0 |   730 |     850    |   110 |   250
  April    |  200|    0 |   700 |     650    |     0 |    80
  May      |  300|    0 |   800 |     600    |     0 |    10
  June     |  500|   50 |  1050 |     950    |     0 |    30
           +-----+------+-------+------------+-------+--------
  July     | 2600|  800 |   ..  |    1100    |    30 |    80
  August   | 5500| 1100 |   ..  |    5900    |  2000 |  1000
  September|   ..|  700 |   ..  |      ..    |    .. |    ..
  October  |   ..|   .. |   ..  |      ..    |    .. |    ..
  November |   ..|   .. |   ..  |      ..    |    .. |    ..
  December |   ..|   .. |   ..  |      ..    |    .. |    ..
           +-----+------+-------+------------+-------+--------
  Year     |   ..|   .. |   ..  |      ..    |    .. |    ..
  =========+=====+======+=======+============+=======+========

  [11] Blue Nile water flowing up the White Nile and decreasing the
  normal discharge.


Appendix H


TABLE XXV.--_Minimum and Maximum Discharges of the Nile and its
tributaries in 1902 and 1903._

                                 1902
  =============+===========+===================+===================
     Name of   | Locality. |   MINIMUM SUMMER  |  MAXIMUM FLOOD
      River.   |           |    DISCHARGE M³   |   DISCHARGE M³
               |           |     PER SECOND    |    PER SECOND
               |           +----------+--------+----------+--------
               |           |   Date.  |  Dis-  |   Date.  |  Dis-
               |           |          | charge.|          | charge.
  -------------+-----------+----------+--------+----------+--------
  Victoria Nile|Ripon Falls|December  |     480|May       |   580
  Albert Nile  |Wadelaï    |April 5th |     530|Dec. 10th |   760
    „          |Gondokoro  |April 15th|     540|Aug. 24th |  1360
    „          |Above Sobat|          |        |          |
  Sobat        |Mouth      |          |        |          |
  White Nile   |Tewfikieh  |April     |app: 340|          |
    „          |Duem       |May, 11th |     340|Dec. 29th |  1500
  Blue Nile    |Khartoum   |April 15th|     180|Aug. 29th |  7200
  Atbara       |Mouth      |          |        |Sept. 8th |  2020
  Nile         |Wadi Haifa |June 2nd  |     490|          |
               |Assuân     |          |        |Sept. 17th|  7000
                                  1903
  Victoria Nile|Ripon Falls|January   |     490|July      |   830
  Albert Nile  |Wadelaï    |April 5th |     630|December  |  1070
    „          |Gondokoro  |April 10th|     680|Sept. 23rd|  2600
    „          |Above Sobat|April     |     430|          |   430
  Sobat        |Mouth      |April 15th|      40|Sept. 15th|  1040
  White Nile   |Tewfikieh  |April     |     380|Dec. 15th |  1470
    „          |Duem       |May 9th   |     400|Nov. 15th |  1670
  Blue Nile    |Khartoum   |May 5th   |     100|Aug. 28th |  9600
  Atbara       |Mouth      |          |        |Aug. 30th |  3100
  Nile         |Wadi Haifa |May 21st  |     420|          |
               |Assuân     |          |        |Sept. 12th|  9000
  =============+===========+==========+========+==========+========


Appendix I.


TABLE XXVI.--_Table of mean monthly Discharges at Khartoum, Assuân and
Cairo, for the maximum, minimum and mean years._

  =========+==================+==================+==================
    Month  |      1877-78     |     1878-79      |     MEAN OF
           |    MINIMUM YEAR  |   MAXIMUM YEAR   |     20 YEARS
           +-----+-----+------+-----+-----+------+-----+-----+------
           | Blue| As- |Cairo.| Blue| As- |Cairo.| Blue| As- |Cairo.
           | Nile|suân.|      | Nile|suân.|      | Nile|suân.|
           |  at |     |      |  at |     |      |  at |     |
           |Khar-|     |      |Khar-|     |      |Khar-|     |
           |toum.|     |      |toum.|     |      |toum.|     |
  ---------+-----+-----+------+-----+-----+------+-----+-----+------
  June     | 1000|  800|  600 | 1000|  500|  250 | 1000|  750|  500
  July     | 2800| 2400| 1100 | 3500| 2000|  900 | 2800| 2200| 1100
  August   | 5300| 5600| 3900 | 8200| 7900| 5200 | 7000| 7900| 5300
  September| 4700| 5900| 4400 |12500|12100| 8600 | 8500| 9200| 7200
  October  | 2500| 4000| 3900 | 8000| 9300|10300 | 4500| 6000| 6900
  November |   ..| 2400| 2550 |   ..| 4700| 6500 |   ..| 3300| 3700
  December |   ..| 1500| 1600 |   ..| 3200| 3600 |   ..| 2200| 2300
  January  |   ..| 1200| 1300 |   ..| 2400| 2600 |   ..| 1600| 1600
  February |   ..|  800|  800 |   ..| 2100| 2100 |   ..| 1200| 1200
  March    |   ..|  600|  550 |   ..| 1900| 1900 |   ..|  850|  800
  April    |   ..|  500|  400 |   ..| 1600| 1600 |   ..|  700|  620
  May      |   ..|  400|  300 |   ..| 1500| 1500 |   ..|  600|  520
  ---------+-----+-----+------+-----+-----+------+-----+-----+------
  Mean     |   ..| 2175| 1783 |   ..| 4100| 3754 |   ..| 3041| 2645
  ---------+-----+-----+------+-----+-----+------+-----+-----+------

NOTE.--The very high discharges at Assuân and Cairo in April and May
1879; the minimum discharge of that year was about 1500 cubic metres per
second. There has never been any discharge like that since.


Appendix J.

DISCHARGE TABLES OF THE DIFFERENT GAUGES OF THE NILE AND ITS
TRIBUTAIRIES.


TABLE XXVII.--_Discharges table of the Victoria Nile at the Ripon
Falls._

  ======+=========+=====================================================
  Gauge.|Discharge|                     Remarks.
        | m³ per  |
        | second. |
  ------+---------+-----------------------------------------------------
    0·0 |     380 |This discharge table is the mean of two alternative
     ·1 |     410 |tables; one assuming that the width of the sill of
     ·2 |     450 |the Ripon Falls was 127 metres as stated by Sir
     ·3 |     480 |William Garstin, the other assuming that only half
     ·4 |     520 |this width was the working sill, the rest being more
     ·5 |     550 |or less shallow water. The constant has been taken as
  ------+---------+·57. Sir William Garstin makes the width of the sill
     ·6 |    580  |70 + 40 + 13 = 127 metres, while Chavanne gives it as
     ·7 |    620  |82 + 14 + 55 + 22 = 173 metres.
     ·8 |    660  |
     ·9 |    700  |The wider the sill, the quicker is the rise of
    1·0 |    740  |discharge from the measured discharge at the gauge of
  ------+---------+·51.
     ·1 |    780  |
     ·2 |    820  |
     ·3 |    860  |
     ·4 |    900  |
     ·5 |    950  |
  ------+---------+
     ·6 |    990  |
     ·7 |   1040  |
     ·8 |   1090  |
     ·9 |   1140  |
    2·0 |   1190  |
  ======+=========+=======================================================


TABLE XXVIII.--_Discharge table of the Albert Nile at Wadelaï._

  ======+============
        | Discharge
  Gauge.|cubic metres
        | per second.
  ------+------------
   0·0  |    520
    ·1  |    544
    ·2  |    568
    ·3  |    592
    ·4  |    616
    ·5  |    640
    ·6  |    668
    ·7  |    696
    ·8  |    724
    ·9  |    752
  ------+------------
   1·0  |    780
    ·1  |    810
    ·2  |    840
    ·3  |    870
    ·4  |    900
    ·5  |    930
    ·6  |    962
    ·7  |    994
    ·8  |   1026
    ·9  |   1058
  ------+------------
   2·0  |   1090
    ·1  |   1104
    ·2  |   1118
    ·3  |   1132
    ·4  |   1146
    ·5  |   1160
  ======+============


TABLE XXIX.--_Discharge Table of the Albert Nile at the Gondokoro
gauge._

  ======+============+===================================================
  Gauge.| Discharge  |                      Remarks.
        |cubic metres|
        | per second.|
  ------+------------+--------------------------------------------------
   0·0  |    550     |There is a scour of a metre and upwards at this
    ·2  |    600     |gauge site during a high flood. The pit is
    ·4  |    660     |apparently filled with sand during a low flood.
    ·6  |    740     |
    ·8  |    820     |
   1·0  |    900     |
  ------+------------+
    ·2  |   1060     |
    ·4  |   1220     |
    ·6  |   1380     |
    ·8  |   1540     |
   2·0  |   1700     |
  ------+------------+
    ·2  |   1900     |
    ·4  |   2100     |
    ·6  |   2300     |
    ·8  |   2500     |
   3·0  |   2700     |
  ======+============+==================================================


TABLE XXX.--_Discharge table of the Albert Nile at the Mongalla gauge,
32 kilometres north of Gondokoro._

  ======+============+=====================================
  Gauge.|  Discharge |              Remarks.
        |cubic metres|
        | per second.|
  ------+------------+-------------------------------------
   0·0  |    500     |This is a better site than Gondokoro.
    ·2  |    540     |
    ·4  |    580     |
    ·6  |    620     |
    ·8  |    660     |
  ------+------------+
   1·0  |    700     |
    ·2  |    780     |
    ·4  |    860     |
    ·6  |    940     |
    ·8  |   1020     |
  ------+------------+
   2·0  |   1100     |
    ·2  |   1300     |
    ·4  |   1500     |
    ·6  |   1700     |
    ·8  |   1900     |
  ------+------------+
   3·0  |   2100     |
    ·2  |   2300     |
    ·4  |   2500     |
    ·6  |   2700     |
  ======+============+=====================================


TABLE XXXI.--_Discharge table of the Sobat river at Dulaib Hilla._

  ======+===========
  Gauge.| Discharge
        |  in m³
        |per second.
  ------+-----------
   0·0  |     30
    ·2  |     58
    ·4  |     86
    ·6  |    112
    ·8  |    142
   1·0  |    170
    ·2  |    218
    ·4  |    266
    ·6  |    314
    ·8  |    362
   2·0  |    410
    ·2  |    500
    ·4  |    590
    ·6  |    680
    ·8  |    790
   3·0  |    860
    ·2  |    950
    ·4  |   1040
    ·6  |   1130
    ·8  |   1220
   4·0  |   1310
  ======+===========

This gauge is in backwater when the north end of the Sudd region is
flooded.


TABLE XXXII.--_Discharge Table of the White Nile at Tewfikieh downstream
of Sobat junction referred to Tewfikia Gauge._

  ======+============
  Gauge.| Discharge
        |  in m³
        |per second.
  ------+------------
   -1·0 |    150
    0·0 |    330
     ·2 |    376
     ·4 |    422
     ·6 |    468
     ·8 |    514
  ------+------------
    1·0 |    560
     ·2 |    616
     ·4 |    672
     ·6 |    728
     ·8 |    784
  ------+------------
    2·0 |    840
     ·2 |    906
     ·4 |    972
     ·6 |   1038
     ·8 |   1104
  ------+------------
    3·0 |   1170
     ·2 |   1270
     ·4 |   1370
     ·6 |   1470
     ·8 |   1570
  ------+------------
    4·0 |   1670
     ·2 |   1770
     ·4 |   1870
     ·6 |   1970
     ·8 |   2070
  ------+------------
    5·0 |   2170
  ======+============


TABLE XXXIII.--_Discharge Table of the White Nile at Duem in Winter and
Summer when the Blue Nile is low._

  ======+===========+===================================================
  Gauge.| Discharge |                     Remarks.
        |  in m³    |
        |per second.|
  ------+-----------+---------------------------------------------------
    0·0 |    330    |This gauge is in backwater when the Blue Nile is
     ·1 |    354    |high.
     ·2 |    370    |
     ·3 |    402    |
     ·4 |    426    |
     ·5 |    450    |
  ------+-----------+
     ·6 |    480    |
     ·7 |    515    |
     ·8 |    555    |
     ·9 |    600    |
    1·0 |    650    |
  ======+===========+===================================================

This table is only very approximative.


TABLE XXXIV.--_Discharge table of the Blue Nile at Wad Medani._

  ======+===================
  Gauge.|     DISCHARGE
        | IN M³ PER SECOND
        +-------+-----------
        | River |   River
        |rising.|  Falling
        |       |    and
        |       |Stationary.
  ------+-------+-----------
    0·0 |    50 |      50
     ·2 |    80 |      64
     ·4 |   110 |      78
     ·6 |   140 |      92
     ·8 |   170 |     106
    1·0 |   200 |     120
     ·2 |   240 |     146
     ·4 |   280 |     172
     ·6 |   320 |     198
     ·8 |   360 |     224
    2·0 |   400 |     250
     ·2 |   450 |     284
     ·4 |   500 |     318
     ·6 |   550 |     352
     ·8 |   600 |     380
    3·0 |   650 |     420
     ·2 |   720 |     406
     ·4 |   790 |     512
     ·6 |   860 |     558
     ·8 |   930 |     604
    4·0 |  1000 |     650
     ·2 |  1100 |     720
     ·4 |  1200 |     790
     ·6 |  1300 |     860
     ·8 |  1400 |     930
    5·0 |  1500 |    1000
     ·2 |  1630 |    1100
     ·4 |  1760 |    1200
     ·6 |  1890 |    1300
     ·8 |  2020 |    1400
    6·0 |  2150 |    1500
     ·2 |  2320 |    1620
     ·4 |  2490 |    1740
     ·6 |  2600 |    1800
     ·8 |  2830 |    1980
    7·0 |  3000 |    2100
     ·2 |  3200 |    2340
     ·4 |  3400 |    2580
     ·6 |  3600 |    2820
     ·8 |  3800 |    3060
    8·0 |  4000 |    3300
     ·2 |  4300 |    3540
     ·4 |  4600 |    3780
     ·6 |  4900 |    4020
     ·8 |  5200 |    4200
    9·0 |  5500 |    4500
     ·2 |  5900 |    4840
     ·4 |  6300 |    5180
     ·6 |  6700 |    5520
     ·8 |  7100 |    5860
   10·0 |  7500 |    6200
     ·2 |  8000 |    6580
     ·4 |  8500 |    6960
     ·6 |  9000 |    7340
     ·8 |  9500 |    7720
   11·0 | 10000 |    8100
     ·2 | 10600 |    8540
     ·4 | 11200 |    8980
     ·6 | 11800 |    9420
     ·8 | 12400 |    9800
   12·0 | 13000 |   10300
  ------+-------+-----------

(1) These discharges include the Rahad river. They represent the
discharges below the Rahad river junction referred to the Wad Medani
gauge.

(2) During a high flood the river scours, and it silts during a low
flood; consequently for exact discharges below 5 metres, the section of
the river should be taken annually in December.


TABLE XXXV.--_Discharge Table of the Blue Nile at the Khartoum Gauge._

  ======+===============+================
  Gauge.|  RIVER RISING |  RIVER FALLING
        |               | AND STATIONARY
        +---------------+----------------
        |Discharge in m³|Discharge in m³
        |  per second.  |  per second.
  ------+---------------+----------------
   - ·2 |       100     |       100
   +0·0 |       175     |       120
     ·2 |       260     |       145
     ·4 |       360     |       170
     ·6 |       470     |       195
     ·8 |       580     |       220
  ------+---------------+----------------
    1·0 |       700     |       250
     ·2 |       860     |       340
     ·4 |      1020     |       430
     ·6 |      1180     |       520
     ·8 |      1340     |       610
  ------+---------------+----------------
    2·0 |      1500     |       700
     ·2 |      1720     |       880
     ·4 |      1940     |      1060
     ·6 |      2160     |      1240
     ·8 |      2380     |      1420
  ------+---------------+----------------
    3·0 |      2600     |      1600
     ·2 |      2980     |      1840
     ·4 |      3360     |      2080
     ·6 |      3740     |      2320
     ·8 |      4120     |      2560
  ------+---------------+----------------
    4·0 |      4500     |      2800
     ·2 |      4980     |      3180
     ·4 |      5460     |      3560
     ·6 |      5940     |      3940
     ·8 |      6420     |      4320
  ------+---------------+----------------
    5·0 |      6900     |      4700
     ·2 |      7560     |      5220
     ·4 |      8220     |      5740
     ·6 |      8880     |      6260
     ·8 |      9540     |      6780
  ------+---------------+----------------
    6·0 |     10200     |      7300
     ·2 |     11000     |      7940
     ·4 |     11800     |      8580
     ·6 |     12600     |      9220
     ·8 |     13400     |      9860
  ------+---------------+----------------
    7·0 |     14200     |     10500
     ·2 |      ...      |     11140
     ·4 |      ...      |     11780
     ·6 |      ...      |     12420
  ======+===============+================

This gauge is in backwater when the White Nile is discharging more than
the Blue Nile.


TABLE XXXVI.--_Discharge Table of the Atbara river referred to the Khasm
el Girba Gauge._

  ======+==========
  Gauge.|Discharge.
  ------+----------
   0·0  |    0·0
    ·2  |     20
    ·4  |     40
    ·6  |     60
    ·8  |     80
  ------+----------
   1·0  |    100
    ·2  |    150
    ·4  |    200
    ·6  |    250
    ·8  |    300
  ------+----------
   2·0  |    350
    ·2  |    444
    ·4  |    538
    ·6  |    632
    ·8  |    726
  ------+----------
   3·0  |    820
    ·2  |   1012
    ·4  |   1204
    ·6  |   1396
    ·8  |   1588
  ------+----------
   4·0  |   1780
    ·2  |   2078
    ·4  |   2376
    ·6  |   2674
    ·8  |   2972
  ------+----------
   5·0  |   3270
    ·2  |   3596
    ·4  |   3922
    ·6  |   4248
    ·8  |   4574
  ------+----------
   6·0  |   4900
  ======+==========


TABLE XXXVII.--_Discharge table for the Assuân, Assiut and Cairo
Gauges._

The gauges are in metres and are referred to mean low-water level as
zero.

  The zero is:
        at Assuân           R. L.  85·00
        at Assiut             „    45·55
        at Cairo              „    12·25

  =N.B.=--At Assiut R. L. 45·55, according to the reservoir levels, is
  R. L. 45·05 according to the 4th Circle levels.

  (The discharges are in cubic metres per second.)

This discharge table may be used approximately for any gauge on the Nile
north of Assuân with its zero at mean low-water level; adding ·5 to the
gauge in Kena Province, and deducting ·5 from the gauge in Minieh and
Beni-Suef.

If the river is rising, take the discharge corresponding to the higher
gauge; if falling or stationary to the lower one.

  ======+==========
  Gauge.|Discharge.
  ------+----------
   -1·0 |    360
   - ·8 |    406
   - ·6 |    452
   - ·4 |    498
   - ·2 |    544
  ------+----------
    0·0 |    590
     ·2 |    668
     ·4 |    746
     ·6 |    824
     ·8 |    902
  ------+----------
    1·0 |    980
     ·2 |   1086
     ·4 |   1192
     ·6 |   1298
     ·8 |   1404
  ------+----------
    2·0 |   1510
     ·2 |   1652
     ·4 |   1794
     ·6 |   1936
     ·8 |   2078
  ------+----------
    3·0 |   2220
     ·2 |   2408
     ·4 |   2596
     ·6 |   2784
     ·8 |   2972
  ------+----------
    4·0 |   3160
     ·2 |   3404
     ·4 |   3648
     ·6 |   3892
     ·8 |   4136
  ------+----------
    5·0 |   4380
     ·2 |   4674
     ·4 |   4968
     ·6 |   5262
     ·8 |   5556
  ------+----------
    6·0 |   5850
     ·2 |   6150
     ·4 |   6450
     ·6 |   6800
     ·8 |   7200
  ------+----------
    7·0 |   7600
     ·2 |   8000
     ·4 |   8400
     ·6 |   8800
     ·8 |   9300
  ------+----------
    8·0 |   9800
     ·2 |  10300
     ·4 |  10900
     ·6 |  11500
     ·8 |  12100
  ------+----------
    9·0 |  12800
     ·2 |  13600
  ======+==========


TABLE XXXVIII.

Discharge Table of the Wady Halfa Gauge, for use at Assuân when the
Assuân Dam is being regulated on, and consequently the Assuân Gauge no
longer represents the normal discharge of the Nile. At this stage of the
river it may be assumed that the water travels normally between Wady
Halfa and Assuân in 3 or 4 days.

  ======+============
        | Discharge
  Gauge.|cubic metres
        | per second.
  ------+------------
   0·8  |    370
   1·0  |    440
    ·2  |    516
    ·4  |    592
    ·6  |    688
    ·8  |    804
  ------+------------
   2·0  |    920
    ·2  |   1048
    ·4  |   1176
    ·6  |   1314
    ·8  |   1462
   3·0  |   1610
  ------+------------
   3·2  |   1800
    ·4  |   1990
    ·6  |   2180
    ·8  |   2370
  ------+------------
   4·0  |   2560
    ·2  |   2802
    ·4  |   3044
    ·6  |   3286
    ·8  |   3528
   5·0  |   3770
  ======+============


TABLE XXXIX.--_Discharge of the Rosetta Branch of the Nile referred to
the Delta Barrage north of Cairo._

  1890
  ======+==============
  Gauge.|   Discharge
        |m³ per second.
  ------+--------------
   0·00 |        0
    ·25 |       50
    ·50 |      100
    ·75 |      150
  ------+--------------
   1·00 |      200
    ·25 |      287
    ·50 |      375
    ·75 |      463
  ------+--------------
   2·00 |      550
    ·25 |      700
    ·50 |      850
    ·75 |     1000
  ------+--------------
   3·00 |     1150
    ·25 |     1312
    ·50 |     1475
    ·75 |     1638
  ------+--------------
   4·00 |     1800
    ·25 |     1975
    ·50 |     2150
    ·75 |     2325
  ------+--------------
   5·00 |     2500
    ·25 |     2700
    ·50 |     2900
    ·75 |     3100
  ------+--------------
   6·00 |     3300
    ·25 |     3525
    ·50 |     3750
    ·75 |     3975
  ------+--------------
   7·00 |     4200
    ·25 |     4450
    ·50 |     4700
    ·75 |     4950
  ------+--------------
   8·00 |     5200
    ·25 |     5475
    ·50 |     5750
    ·75 |     6025
  ------+--------------
   9·00 |     6300
  ======+==============

Zero of the gauge R. L. 10·00 metres above mean sea.


TABLE XL.--_Discharge of the Damietta Branch of the Nile referred to the
Delta Barrage north of Cairo._

  1890
  ======+=========
  Gauge.|Discharge
        | m³ per
        | second.
  ------+---------
   0·00 |     0
    ·25 |    20
    ·50 |    40
    ·75 |    60
  ------+-----------
   1·00 |    80
    ·25 |   110
    ·50 |   140
    ·75 |   170
  ------+-----------
   2·00 |   200
    ·25 |   262
    ·50 |   325
    ·75 |   388
  ------+-----------
   3·00 |   450
    ·25 |   537
    ·50 |   625
    ·75 |   712
  ------+-----------
   4·00 |   800
    ·25 |   925
    ·50 |  1050
    ·75 |  1175
  ------+-----------
   5·00 |  1300
    ·25 |  1450
    ·50 |  1600
    ·75 |  1750
  ------+-----------
   6·00 |  1900
    ·25 |  2075
    ·50 |  2250
    ·75 |  2425
  ------+-----------
   7·00 |  2600
    ·25 |  2800
    ·50 |  3000
    ·75 |  3200
  ------+-----------
   8·00 |  3400
    ·25 |  3625
    ·50 |  3850
    ·75 |  4075
  ------+-----------
   9·00 |  4300
  ------+-----------

NOTE.--Zero of the gauge R. L. 10·00 metres above mean sea.


Appendix K.

TABLES GIVING DETAILED INFORMATION ABOUT THE NILE BETWEEN ASSUÂN AND
CAIRO.


TABLE XLI.--_Date of Heights of Minimum gauges in summer and Maximum
gauges in flood at Assuan._

  =====+===================+===================
  Year.|  MINIMUM SUMMER   |   MAXIMUM FLOOD
       +------------+------+------------+------
       |    Date.   |Gauge.|    Date.   |Gauge.
  -----+------------+------+------------+------
   1873| 5 June     | -0·37| 1 September| 7·66
   1874|30 May      | -0·64| 6 September| 8·97
   1875|23 May      | -0·17|11 September| 8·36
   1876|15 June     | +0·13| 7 September| 8·68
   1877|27 May      | +0·10|20 August   | 6·40
   1878|23 June     | -0·71| 1 October  | 9·15
   1879|23 May      | +1·88|13 September| 8·59
   1880| 9 June     | +0·82| 4 September| 7·82
   1881|14 May      | +0·00| 4 September| 8·14
   1882|23 June     | -0·55|28 August   | 8·00
   1883|22 June     | +0·04|17 September| 8·18
   1884|27 May      | +0·37| 1 September| 7·73
   1885|21 June     | -0·44|28 August   | 8·05
   1886| 3 June     | -0·06|22 September| 8·04
   1887| 8 May      | -0·03| 1 September| 8·81
   1888| 8 June     | -0·08|24 August   | 7·08
   1889|24 June     | -0·60| 2 September| 8·36
   1890| 8 June     | -0·60| 2 September| 8·72
   1891|19 May      | -0·21|27 September| 7·84
   1892|18 June     | -0·64|20 September| 8·88
   1893|18 June     | +0·35|14 September| 7·75
   1894|16 June     | +0·06|18 September| 8·61
   1895|23 June     | +0·78|10 September| 8·68
   1896|13 June     | +0·49| 3 September| 8·63
   1897|31 May      | +0·62| 1 September| 7·80
   1898|23 June     | -0·25|29 August   | 8·63
   1899| 1 June     | +0·15| 4 September| 6·67
   1900|15 May      | -0·93|19 August   | 7·91
   1901|10 May      | -0·46| 6 September| 7·82
   1902|12 May      | -0·48|17 September| 6·72
   1903|16 April    | -0·68|27 August   | 7·93
   1904| 5 June     | -0·20|13 August   | 6·97
  =====+============+======+============+======

Zero is R. L. 85·00 metres or mean low water level.


TABLE XLII.--_Table giving areas of cross sections of the Nile, from
Assuân to Cairo._

  ================+=======+=============================================
      Locality.   | Length|        MEAN AREA IN SQUARE METRES
                  |  in   +-----+-------+-------+-------+-------+-------
                  | kilo- |Below| Below | Below | Below | Below | Below
                  |metres.|zero.|   6   |   7   |   8   |  8.5  |   9
                  |       |     |metres.|metres.|metres.|metres.|metres.
  ----------------+-------+-----+-------+-------+-------+-------+-------
  Assuân to Ramâdi|   81  | 1024|  4930 |  5808 |  6754 |  7337 |  7993
  Ramâdi to Esna  |   76  |  674|  4554 |  5461 |  6398 |  6966 |  7695
  Esna to Kena    |  115  |  852|  4476 |  5336 |  6221 |  6726 |  7363
  Kena to Sohâg   |  158  |  973|  4718 |  5600 |  6535 |  7121 |  7873
  Sohâg to Assiout|   98  | 1037|  5220 |  6305 |  7705 |  8683 |  9749
  Assiout to Minia|  138  |  899|  5149 |  6205 |  7783 |  8845 |  9937
  Minia to Beni-  |       |     |       |       |       |       |
  Suêf            |  117  |  915|  5035 |  6007 |  7315 |  8196 |  9140
  Beni-Suêf to    |       |     |       |       |       |       |
  Koshesha        |   34  |  665|  5040 |  6080 |  7532 |  8379 |  9247
  Koshesha to     |       |     |       |       |       |       |
  Cairo           |   81  | 1031|  5364 |  6388 |  7813 |  8648 |  9495
  Cairo to the    |       |     |       |       |       |       |
  Barrage         |   24  | 1402|  5414 |  6628 |  8346 |  9258 | 10184
  ----------------+-------+-----+-------+-------+-------+-------+-------
  Assuân to       |       |     |       |       |       |       |
  Assiout         |  528  |  920|  4760 |  5680 |  6690 |  7310 |  8080
  Assiout to      |       |     |       |       |       |       |
  Koshesha        |  289  |  870|  5080 |  6100 |  7550 |  8510 |  9520
  Koshesha to     |       |     |       |       |       |       |
  Cairo           |   81  | 1030|  5360 |  6380 |  7810 |  8640 |  9490
  ----------------+-------+-----+-------+-------+-------+-------+-------
  Assuân to Cairo |  898  |  910|  4930 |  5890 |  7080 |  7830 |  8690
  ================+=======+=====+=======+=======+=======+=======+=======


TABLE XLIII.--_Table of the cubic contents of the trough of the Nile
from Assuân to Cairo in millions of cubic metres._

  =====================+========+==============================+
      Locality.        | Length |     CONTENTS IN MILLIONS     |
                       |in kilo-|       OF CUBIC METRES        |
                       |metres. +-----+----+----+----+----+----+
                       |        |Below|From| 6.0| 7.0| 8.0| 8.5|
                       |        |zero.|zero| to | to | to | to |
                       |        |     | to | 7.0| 8.0| 8.5| 9.0|
                       |        |     |6.0 |    |    |    |    |
  ---------------------+--------+-----+----+----+----+----+----+
                       |        |     |    |    |    |    |    |
  Assuân to Ramadi     |    81  |   83| 316| 711|  77|  47|  53|
  Ramadi to Esna       |    76  |   51| 295|  69|  71|  43|  56|
  Esna to Kena         |   115  |   98| 417|  99| 102|  58|  73|
  Kena to Sohag        |   128  |  154| 592| 139| 148|  83| 119|
  Sohag to Assiout     |    98  |  102| 410| 106| 137|  96| 104|
  Assiout to Minieh    |   138  |  124| 586| 146| 218| 147| 151|
  Minieh to Beni Suêf  |   117  |  107| 482| 114| 153| 103| 110|
  Beni Suêf to Kushesha|    34  |   23| 149|  35|  49|  29|  29|
  Kushesha to Cairo    |    81  |   84| 351|  83| 115|  68|  69|
  Cairo to the Barrage |    28  |   34|  96|  29|  41|  22|  22|
                       +--------+-----+----+----+----+----+----+
  Assuân to Assiout    |   528  |  487|2030| 484| 534| 327| 405|
  Assiout to Kushesha  |   289  |  254|1217| 295| 420| 278| 291|
  Kushesha to Cairo    |    81  |   84| 351|  83| 115|  68|  69|
                       +--------+-----+----+----+----+----+----+
  Assuân to Cairo      |   898  |  825|3598| 862|1069| 673| 765|
  =====================+========+=====+====+====+====+====+====+

  =====================+========+==============================
      Locality.        | Length |   CONTENTS IN MILLIONS
                       |in kilo-|     OF CUBIC METRES
                       |metres. +-----+-----+-----+-----+-----
                       |        |Below|Below|Below|Below|Below
                       |        | 6.0 | 7.0 | 8.0 | 8.5 | 9.0
                       |        |     |     |     |     |
                       |        |     |     |     |
  ---------------------+--------+-----+-----+-----+-----+-----
                       |        |     |     |     |     |
  Assuân to Ramadi     |    81  |  399|  470|  547|  594|  647
  Ramadi to Esna       |    76  |  346|  415|  486|  529|  585
  Esna to Kena         |   115  |  514|  614|  715|  773|  847
  Kena to Sohag        |   128  |  745|  885| 1032| 1125| 1244
  Sohag to Assiout     |    98  |  512|  618|  755|  851|  955
  Assiout to Minieh    |   138  |  710|  856| 1074| 1220| 1371
  Minieh to Beni Suêf  |   117  |  589|  703|  856|  859| 1069
  Beni Suêf to Kushesha|    34  |  171|  207|  256|  285|  314
  Kushesha to Cairo    |    81  |  434|  517|  633|  700|  769
  Cairo to the Barrage |    28  |  130|  159|  200|  222|  244
                       +--------+-----+-----+-----+-----+-----
  Assuân to Assiout    |   528  | 2517| 3001| 3535| 3862| 4267
  Assiout to Kushesha  |   289  | 1471| 1766| 2186| 2464| 2755
  Kushesha to Cairo    |    81  |  435|  518|  633|  701|  770
                       +--------+-----+-----+-----+-----+-----
  Assuân to Cairo      |   898  | 4423| 5285| 6354| 7027| 7792
  =====================+========+=====+=====+=====+=====+=====


TABLE XLIV.--_Widths of water surface from Assuân to Cairo._

  =========+=========+============================
    From.  |   To.   |MEAN WIDTH OF WATER SURFACE
           |         +---+----+----+----+----+----
           |         | 0 | 6·0| 7·0| 8·0| 8·5| 9·0
  ---------+---------+---+----+----+----+----+----
  Assuân   |Ramadi   |400| 840| 880|1030|1270|1400
  Ramadi   |Esna     |340| 850| 890|1030|1260|1620
  Esna     |Kena     |350| 820| 850| 940|1120|1400
  Kena     |Sohag    |380| 870| 890|1000|1300|1560
  Sohag    |Assiout  |400|1000|1170|1720|2080|2170
  Assiout  |Minieh   |390| 970|1180|1890|2060|2080
  Minieh   |Beni Suêf|490| 960|1300|1550|1800|1840
  Beni Suêf|Kushesha |500|1000|1390|1690|1720|1730
  Kushesha |Cairo    |450| 960|1100|1570|1700|1700
  Cairo    |Barrage  |440| 940|1460|1840|1860|1890
  ---------+---------+---+----+----+----+----+-----
  Assuân   |Assiout  |370| 880| 940|1140|1410|1630
  Assiout  |Kushesha |460| 980|1290|1710|1860|1880
  Kushesha |Cairo    |450| 960|1100|1570|1700|1700
  ---------+---------+---+----+----+----+----+----
  Assuân   |Cairo    |430| 940|1110|1470|1660|1740
  ---------+---------+---+----+----+----+----+----

_Area of water surface in millions of square metres._

  =========+=========+===+====+====+====+====+====
  Assuân   |Assiout  |200| 470| 500| 600| 740| 860
  Assiout  |Cairo    |130| 280| 370| 490| 540| 540
  Assuân   |Cairo    |400| 840|1000|1320|1490|1560
  =========+=========+===+====+====+====+====+====


TABLE XLV.--_Slope of water surface in the Nile. Assuân to Cairo._

  ============+============+========+========+=======+=======
      From.   |   To.      |Distance|Distance| Slope | Slope
              |            |in kilo-|in kilo-|   in  |   in
              |            |metres  |metres  | flood.|summer.
              |            |down the|down the|       |
              |            |centre  |summer  |       |
              |            |line of |channel.|       |
              |            |the     |        |       |
              |            |flood.  |        |       |
  ------------+------------+--------+--------+-------+-------
  Assuân      |Silsila     |    70  |    72  |¹⁄₁₁₅₀₀|¹⁄₁₂₆₀₀
  Silsila     |Kasr-es-Saad|   250  |   258  |¹⁄₁₄₈₀₀|¹⁄₁₄₈₀₀
  Kasr-es-Saad|Khazindaria |   150  |   159  |¹⁄₁₂₃₀₀|¹⁄₁₃₄₀₀
  Khazindaria |Assiout     |    60  |    63  |¹⁄₁₁₈₀₀|¹⁄₁₄₅₀₀
  Assiout     |Beni Mazâr  |   180  |   196  |¹⁄₁₁₀₀₀|¹⁄₁₁₈₀₀
  Beni Mazâr  |Ashmant     |    90  |    94  |¹⁄₁₁₀₀₀|¹⁄₁₁₄₀₀
  Ashmant     |Cairo       |   100  |   106  |¹⁄₁₁₆₀₀|¹⁄₁₂₃₀₀
  Cairo       |Barrage     |    23  |    25  |¹⁄₁₀₈₀₀|¹⁄₂₀₀₀₀
  ------------+------------+--------+--------+-------+-------
  Assuân      | Cairo      |   900  |   948  |¹⁄₁₂₂₀₀|¹⁄₁₃₀₀₀
  ============+============+========+========+=======+=======


TABLE XLVI.--_Mean low water level of the Nile--Assuân to Cairo._

  ========+===============+=========+==========+========
  Distance|    Name of    |  R. L.  |  R. L.   |Distance
    from  |   Locality.   |According|According |  from
   Assuân |               |   to    |   to     | Assuân
    along |               |reservoir|inspectors| along
   centre |               | levels. |   of     | summer
     of   |               |         | irriga-  |Channel.
   flood. |               |         |  tion.   |
  --------+---------------+---------+----------+--------
       0  |Assuân         |  85·0   |   85·0   |    0
      70  |Gebel Silsila  |  79·3   |   79·4   |   72
     106  |Edfu           |  76·7   |   77·0   |   ..
     157  |Esna           |  73·1   |   72·6   |   ..
     194  |Armant         |  70·1   |   69·6   |   ..
     213  |Luxor          |  69·0   |   68·5   |   ..
     272  |Kena           |  65·3   |   64·8   |   ..
     320  |Kasr-es-Saad   |  61·7   |   61·2   |  330
     328  |Heu            |  61·2   |   60·7   |   ..
     333  |Naga Hamadi    |  61·0   |   60·5   |   ..
     365  |Abu Shusha     |  58·6   |   58·1   |   ..
     373  |Balyana        |  58·3   |   57·8   |   ..
     390  |Girga          |  56·9   |   56·5   |   ..
     429  |Sohâg          |  53·8   |   53·2   |   ..
     470  |Khazindaria    |  49·9   |   49·4   |  489
     505  |Aboutig Escape |  47·7   |   47·1   |   ..
     530  |Assiout[12]    |  45·55  |   45·05  |  552
     598  |Derut Escape   |  39·1   |   38·5   |   ..
     627  |Roda           |  36·3   |   35·7   |   ..
     666  |Minia          |  32·6   |   32·0   |   ..
     710  |Beni Mazâr     |  28·9   |     ..   |  748
          |Beni Suêf[13]  |  22·1   |   21·8   |   ..
     800  |Ashmant        |  20·5   |   20·2   |  842
          |Kushesha Escape|  18·9   |   18·6   |   ..
          |El-Ayât        |  15·8   |   15·5   |   ..
     898  |Cairo gauge    |  12·10  |   12·25  |   ..
     900  |Cairo          |  12·00  |   12·1   |  948
  ========+===============+=========+==========+========

  [12] Downstream of the Assiout weir.

  [13] The Beni Suêf gauge is unreliable in summer as it is on a branch
  of the river which is dammed by the villagers.


TABLE XLVII.--_Discharge table of the Upper Egypt canals._

  A low Nile flood is  6·4 metres }
  A mean Nile flood is 7·5   „    } at Assuân.
  A high Nile flood is 8·3   „    }

The discharges of the Upper Egypt canals corresponding to the Assuân
gauges are approximately as follows:--

  Assuân    6·0    1300
             ·1    1370
             ·2    1440
             ·3    1510
             ·4    1580--Low Nile flood.
             ·5    1650
             ·6    1620
             ·7    1790
             ·8    1860
             ·9    1930
            7·0    2000
            -----------
             ·1    2070
             ·2    2140
             ·3    2210
             ·4    2280
             ·5    2350--Mean Nile flood.
             ·6    2420
             ·7    2490
             ·8    2560
             ·9    2630
            8·0    2700
            -----------
             ·1    2770
             ·2    2840
             ·3    2910--High Nile flood.
             ·4    2980
             ·5    3050
             ·6    3120
             ·7    3190
             ·8    3260
             ·9    3330
            9·0    3400
  =======================================

R. L. of zero in R. L. 85·00 metres.


TABLE XLVIII.--_Canal discharges between Assuan and Assiut._

DISCHARGES OF THE CANALS IN UPPER EGYPT IN 1892.

  ==============+===================+=============================
  Name of Canal.|       AUGUST      |          SEPTEMBER
                +----+----+----+----+----+----+----+----+----+----
                | 15 | 20 | 25 | 31 |  5 | 10 | 15 | 20 | 25 | 30
  --------------+----+----+----+----+----+----+----+----+----+----
  Ramadi        |  55|  66|  80|  76|  82|  85|  89|  91|  ..|  ..
  Um-Ads        |   8|   9|  12|  13|  16|  18|  20|  ..|  ..|  ..
  Afsûn         |  25|  29|  37|  39|  42|  43|  45|  ..|  ..|  ..
  Fadilia       |  12|  26|  44|  49|  52|  55|  50|  ..|  ..|  ..
  Toukh         |  10|  19|  37|  42|  44|  58|  60|  ..|  ..|  ..
  Rannan        |  28|  36|  53|  59|  62|  67|  70|  ..|  ..|  ..
  Dumrania      |  26|  35|  56|  62|  65|  70|  74|  ..|  ..|  ..
  Rashwania     |  35|  41|  58|  61|  64|  70|  73|  ..|  ..|  ..
  Kasra         |  49|  62| 104| 133| 138| 150| 150|  ..|  ..|  ..
  Zarzria       |  24|  30|  64|  76|  77|  90|  90|  ..|  ..|  ..
  Girgawia      |  54|  59|  84|  95|  96| 120| 120|  ..|  ..|  ..
  Sohagia       | 380| 386| 470| 485| 492| 520| 500|  ..|  ..|  ..
  Tahta         |  44|  45|  66|  75|  77|  82|  85|  ..|  ..|  ..
  Shatura       |  25|  24|  39|  47|  49|  45|  40|  ..|  ..|  ..
  Ibrahimia     | 460| 440| 540| 600| 640| 700| 740|  ..|  ..|  ..
  Waladia       |   6|   6|  14|  20|  24|  24|  24|  ..|  ..|  ..
  Minor Canals  |  10|  15|  20|  30|  30|  30|  20|  ..|  ..|  ..
                +----+----+----+----+----+----+----+----+----+----
  Total left    |    |    |    |    |    |    |    |    |    |
  bank          |1250|1320|1790|1980|2060|2250|2270|  ..|  ..|  ..
                +----+----+----+----+----+----+----+----+----+----
  Kilibia       |   6|  11|  17|  20|  24|  28|  32|  ..|  ..|  ..
  Maala         |   5|   5|  18|  22|  26|  30|  32|  ..|  ..|  ..
  Bayadiâ       |  30|  36|  62|  69|  77|  85|  90|  ..|  ..|  ..
  Shanhuria     |  46|  55|  98| 108| 116| 120| 125|  ..|  ..|  ..
  Shekhia       |   5|   6|  10|  11|  12|  12|  12|  ..|  ..|  ..
  Gilasi        |  19|  30|  58|  64|  68|  70|  72|  ..|  ..|  ..
  Samatha       |  12|  19|  41|  48|  52|  60|  60|  ..|  ..|  ..
  Tarif         |  10|  15|  20|  25|  25|  25|  25|  ..|  ..|  ..
  Hawis         |  15|  22|  38|  41|  44|  51|  56|  ..|  ..|  ..
  Ahaiwia       |  10|  15|  20|  25|  25|  25|  25|  ..|  ..|  ..
  Isaiwia       |  35|  35|  55|  60|  63|  70|  70|  ..|  ..|  ..
  Khizindaria   |  63|  62|  86|  96|  98| 110|  95|  ..|  ..|  ..
  Maanah        |  35|  41|  58|  67|  71|  80|  85|  ..|  ..|  ..
  Sant          |   6|   7|   8|  10|  10|  12|  12|  ..|  ..|  ..
  Minor Canals  |   4|   8|  12|  15|  15|  15|  15|  ..|  ..|  ..
                +----+----+----+----+----+----+----+----+----+----
  Total right   |    |    |    |    |    |    |    |    |    |
  bank          | 300| 370| 600| 680| 730| 800| 810|  ..|  ..|  ..
                +----+----+----+----+----+----+----+----+----+----
  Total both    |    |    |    |    |    |    |    |    |    |
  banks         |1550|1690|2390|2660|2790|3050|3080|  ..|  ..|  ..
  ==============+====+====+====+====+====+====+====+====+====+====


TABLE XLVIII (continued).--_Canal discharges between Assiout and Cairo._

DISCHARGES OF THE CANALS IN UPPER EGYPT IN 1892.

  ==============+===================+=============================
  Name of Canal.|       AUGUST      |          SEPTEMBER
                +----+----+----+----+----+----+----+----+----+----
                | 15 | 20 | 25 | 31 |  5 | 10 | 15 | 20 | 25 | 30
  --------------+----+----+----+----+----+----+----+----+----+----
  Beni-Husain   |  13|  16|  20|  30|  35|  40|  ..|  ..|  ..|  ..
  Abu-Bakra     |  53|  38|  60|  80|  85|  93|  ..|  ..|  ..|  ..
  Sultani       |  18|  10|  20|  37|  38|  40|  ..|  ..|  ..|  ..
  Nina          |   9|   5|  10|  20|  20|  20|  ..|  ..|  ..|  ..
  Bahabshin     |  12|   8|  14|  27|  28|  33|  ..|  ..|  ..|  ..
  Magnuna       |  15|  15|  22|  40|  45|  45|  ..|  ..|  ..|  ..
  Kusheha       |  70|  70|  70|  70|  70|  70|  ..|  ..|  ..|  ..
  Zawia         |  11|   7|  16|  27|  28|  33|  ..|  ..|  ..|  ..
  Girza         |  40|  38|  70|  95| 100| 100|  ..|  ..|  ..|  ..
  Zumr          |  13|  12|  14|  19|  20|  19|  ..|  ..|  ..|  ..
  Minor Canals  |   2|   2|   4|   4|   4|   4|  ..|  ..|  ..|  ..
                +----+----+----+----+----+----+----+----+----+----
  Total left    |    |    |    |    |    |    |    |    |    |
  bank          | 260| 220| 320| 450| 480| 500|  ..|  ..|  ..|  ..
                +----+----+----+----+----+----+----+----+----+----
  Aly Bey       |  14|  13|  28|  33|  20|  18|  ..|  ..|  ..|  ..
  Khassâb       |  19|  14|  25|  35|  40|  46|  ..|  ..|  ..|  ..
  Minor Canals  |   7|   6|  12|  12|  14|  14|  ..|  ..|  ..|  ..
                +----+----+----+----+----+----+----+----+----+----
  Total right   |    |    |    |    |    |    |    |    |    |
  bank          |  40|  30|  70|  80|  80|  80|  ..|  ..|  ..|  ..
                +----+----+----+----+----+----+----+----+----+----
  Total both    |    |    |    |    |    |    |    |    |    |
  banks         | 300| 250| 390| 530| 560| 580|  ..|  ..|  ..|  ..
  ==============+====+====+====+====+====+====+====+====+====+====

_Canal discharges between Assuân and Cairo._

  ==============+====+====+====+====+====+====+====+====+====+====
  Left bank     |1510|1540|2110|2430|2540|2750|  ..|  ..|  ..|  ..
  Right bank    | 340| 400| 670| 760| 810| 880|  ..|  ..|  ..|  ..
                +----+----+----+----+----+----+----+----+----+----
  Total         |1850|1940|2780|3190|3390|3630|  ..|  ..|  ..|  ..
                +----+----+----+----+----+----+----+----+----+----
  Assuân gauge  | 6·7| 7·4| 8·3| 8·3|8·6 | 8·8| 8·7|  ..|  ..|  ..
  Assiout gauge | 6·1| 5·9| 6·8| 7·2|7·4 | 7·7| 8·1|  ..|  ..|  ..
  Cairo gauge   | 5·8| 5·5| 5·8| 6·7|7·0 | 7·2| 7·7|  ..|  ..|  ..
  ==============+====+====+====+====+====+====+====+====+====+====


TABLE XLIX.--_Canal discharges between Assuan and Assiut._

DISCHARGES OF THE CANALS IN UPPER EGYPT IN 1893.

  ==============+===================+=============================+
  Name of Canal.|       AUGUST      |          SEPTEMBER          |
                +----+----+----+----+----+----+----+----+----+----+
                | 15 | 20 | 25 | 31 |  5 | 10 | 15 | 20 | 25 | 30 |
  --------------+----+----+----+----+----+----+----+----+----+----+
  Ramadi        |  50|  56|  58|  56|  55|  60|  64|  61|  64|  61|
  Um-Ads        |  10|  12|  12|  12|  13|  14|  15|  15|  15|  15|
  Asfun         |  28|  33|  34|  33|  31|  33|  35|  33|  34|  33|
  Fadilia       |  17|  24|  26|  26|  22|  24|  29|  24|  22|  20|
  Toukh         |  19|  24|  26|  27|  21|  24|  24|  22|  27|  26|
  Rannan        |  20|  26|  29|  28|  25|  25|  30|  27|  30|  28|
  Dumrania      |  33|  39|  44|  43|  39|  41|  46|  43|  46|  44|
  Rashwania     |  45|  52|  60|  55|  50|  53|  68|  60|  65|  60|
  Kasra         |  70|  72|  82|  79|  72|  76|  87|  82|  87|  82|
  Zarzuria      |  38|  44|  47|  46|  45|  47|  52|  46|  52|  46|
  Gergawia      |  55|  55|  59|  58|  56|  56|  62|  57|  62|  57|
  Sohagia       | 390| 380| 400| 390| 350| 360| 420| 390| 430| 410|
  Tahta         |  45|  46|  47|  46|  44|  45|  51|  44|  52|  47|
  Shatura       |  20|  23|  26|  25|  22|  17|  28|  25|  29|  28|
  Ibrahimia     | 520| 520| 560| 560| 540| 540| 600| 580| 600| 600|
  Waladia       |  10|  11|  12|  12|  11|  11|  11|  12|  12|  12|
  Minor Canals  |  10|  15|  20|  20|  20|  20|  20|  20|  20|  20|
                +----+----+--------------+----+----+----+----+----+
  Total left    |    |    |    |    |    |    |    |    |    |    |
  bank          |1380|1430|1550|1510|1420|1440|1640|1540|1650|1590|
                +----+----+----+----+----+----+----+----+----+----+
  Kilibia       |  11|  13|  15|  14|  14|  15|  17|  16|  16|  16|
  Maala         |  11|  12|  13|  12|  13|  14|  16|  16|  16|  16|
  Bayadia       |  36|  44|  48|  46|  40|  45|  52|  44|  42|  30|
  Shanhuria     |  56|  64|  69|  63|  62|  64|  70|  50|  40|  30|
  Shekhia       |   6|   7|   9|   8|   6|   6|   4|   5|   6|   6|
  Gilasi        |  24|  32|  34|  32|  29|  30|  35|  31|  34|  33|
  Samatha       |  17|  24|  27|  25|  22|  24|  28|  25|  27|  26|
  Tarif         |  12|  14|  16|  15|  14|  15|  17|  16|  17|  16|
  Hawis         |  24|  27|  29|  29|  27|  27|  29|  27|  25|  16|
  Ahaiwia       |  15|  16|  16|  16|  12|  12|  10|   7|   4|   4|
  Isawia        |  30|  37|  40|  37|  37|  39|  40|  40|  43|  40|
  Khazindaria   |  60|  62|  67|  66|  60|  60|  66|  65|  55|  50|
  Maanah        |  20|  30|  32|  32|  29|  32|  33|  34|  24|  24|
  Sant          |   6|   6|   9|   8|   7|   7|   7|   7|   7|   7|
  Minor Canals  |   4|   7|  10|  10|  10|  10|  10|  10|  10|  10|
                +----+----+----+----+----+----+----+----+----+----+
  Total right   |    |    |    |    |    |    |    |    |    |    |
  bank          | 340| 400| 430| 410| 390| 400| 430| 390| 370| 320|
                +----+----+----+----+----+----+----+----+----+----+
  Total both    |    |    |    |    |    |    |    |    |    |    |
  banks         |1720|1830|1980|1920|1810|1840|2070|1930|2020|1910|
  ==============+====+====+====+====+====+====+====+====+====+====+

  ==============+========================
  Name of Canal.|         OCTOBER
                +----+----+----+----+----
                |  5 | 10 | 15 | 20 | 25
  --------------+----+----+----+----+----
  Ramadi        |  ..|  ..|  ..|  ..|  ..
  Um-Ads        |  ..|  ..|  ..|  ..|  ..
  Asfun         |  ..|  ..|  ..|  ..|  ..
  Fadilia       |  ..|  ..|  ..|  ..|  ..
  Toukh         |  ..|  ..|  ..|  ..|  ..
  Rannan        |  ..|  ..|  ..|  ..|  ..
  Dumrania      |  ..|  ..|  ..|  ..|  ..
  Rashwania     |  ..|  ..|  ..|  ..|  ..
  Kasra         |  ..|  ..|  ..|  ..|  ..
  Zarzuria      |  ..|  ..|  ..|  ..|  ..
  Gergawia      |  ..|  ..|  ..|  ..|  ..
  Sohagia       |  ..|  ..|  ..|  ..|  ..
  Tahta         |  ..|  ..|  ..|  ..|  ..
  Shatura       |  ..|  ..|  ..|  ..|  ..
  Ibrahimia     |  ..|  ..|  ..|  ..|  ..
  Waladia       |  ..|  ..|  ..|  ..|  ..
  Minor Canals  |  ..|  ..|  ..|  ..|  ..
                +----+----+----+----+----
  Total left    |    |    |    |    |
  bank          |  ..|  ..|  ..|  ..|  ..
                +----+----+----+----+----
  Kilibia       |  ..|  ..|  ..|  ..|  ..
  Maala         |  ..|  ..|  ..|  ..|  ..
  Bayadia       |  ..|  ..|  ..|  ..|  ..
  Shanhuria     |  ..|  ..|  ..|  ..|  ..
  Shekhia       |  ..|  ..|  ..|  ..|  ..
  Gilasi        |  ..|  ..|  ..|  ..|  ..
  Samatha       |  ..|  ..|  ..|  ..|  ..
  Tarif         |  ..|  ..|  ..|  ..|  ..
  Hawis         |  ..|  ..|  ..|  ..|  ..
  Ahaiwia       |  ..|  ..|  ..|  ..|  ..
  Isawia        |  ..|  ..|  ..|  ..|  ..
  Khazindaria   |  ..|  ..|  ..|  ..|  ..
  Maanah        |  ..|  ..|  ..|  ..|  ..
  Sant          |  ..|  ..|  ..|  ..|  ..
  Minor Canals  |  ..|  ..|  ..|  ..|  ..
                +----+----+----+----+----
  Total right   |    |    |    |    |
  bank          |  ..|  ..|  ..|  ..|  ..
                +----+----+----+----+----
  Total both    |    |    |    |    |
  banks         |  ..|  ..|  ..|  ..|  ..
  ==============+====+====+====+====+====


TABLE XLIX (continued).--_Canal discharges between Assiout and Cairo._

DISCHARGES OF THE CANALS IN UPPER EGYPT IN 1893.

  ==============+===================+=============================+
  Name of Canal.|       AUGUST      |          SEPTEMBER          |
                +----+----+----+----+----+----+----+----+----+----+
                | 15 | 20 | 25 | 31 |  5 | 10 | 15 | 20 | 25 | 30 |
  --------------+----+----+----+----+----+----+----+----+----+----+
  Beni Husain   |  17|  18|  19|  20|  14|  12|  16|  17|  17|  17|
  Abu-Bakra     |  63|  50|  63|  64|  60|  58|  68|  65|  64|  64|
  Sultani       |  17|  16|  17|  17|  16|  15|  17|  17|  17|  17|
  Nina          |   9|   8|   9|  10|  10|   9|   9|   9|   9|   9|
  Bahabshin     |  11|   9|  11|  12|  12|  10|  12|  11|  13|  14|
  Magnuna       |  21|  20|  20|  20|  24|  23|  28|  29|  30|  30|
  Kushâska      |  70|  70|  50|  30|   0|   0|   0|   0|   0|   0|
  Zawia         |  11|   8|  13|  12|  13|  12|  13|  15|  16|  17|
  Girza         |  50|  45|  50|  55|  60|  60|  50|  50|  40|  30|
  Zumr          |  10|  10|  10|  10|   6|   6|   7|  12|  14|  15|
  Minor Canals  |   2|   2|   2|   2|   2|   2|   2|   2|   2|   2|
                +----+----+----+----+----+----+----+----+----+----+
  Total left    |    |    |    |    |    |    |    |    |    |    |
  bank          |280 |260 | 260| 250| 220| 210| 220| 220| 220| 220|
                +----+----+----+----+----+----+----+----+----+----+
  Ali bey       |  16|  20|  27|  28|  15|  12|  15|  17|  20|  20|
  Khassab       |  20|  20|  20|  22|  19|  15|  19|  15|  15|  18|
  Minor Canals  |   6|   6|   6|   6|   7|   7|   7|   7|   7|   7|
                +----+----+----+----+----+----+----+----+----+----+
  Total right   |    |    |    |    |    |    |    |    |    |    |
  bank          |  40|  50|  50|  60|  40|  30|  40|  40|  40|  50|
                +----+----+----+----+----+----+----+----+----+----+
  Total both    |    |    |    |    |    |    |    |    |    |    |
  banks         | 320| 310| 310| 310| 260| 240| 260| 260| 260| 270|
  ==============+====+====+====+====+====+====+====+====+====+====+

  ==============+========================
  Name of Canal.|         OCTOBER
                +----+----+----+----+----
                |  5 | 10 | 15 | 20 | 25
  --------------+----+----+----+----+----
  Beni Husain   |  ..|  ..|  ..|  ..|  ..
  Abu-Bakra     |  ..|  ..|  ..|  ..|  ..
  Sultani       |  ..|  ..|  ..|  ..|  ..
  Nina          |  ..|  ..|  ..|  ..|  ..
  Bahabshin     |  ..|  ..|  ..|  ..|  ..
  Magnuna       |  ..|  ..|  ..|  ..|  ..
  Kushâska      |  ..|  ..|  ..|  ..|  ..
  Zawia         |  ..|  ..|  ..|  ..|  ..
  Girza         |  ..|  ..|  ..|  ..|  ..
  Zumr          |  ..|  ..|  ..|  ..|  ..
  Minor Canals  |  ..|  ..|  ..|  ..|  ..
                +----+----+----+----+----
  Total left    |    |    |    |    |
  bank          |  ..|  ..|  ..|  ..|  ..
                +----+----+----+----+----
  Ali bey       |  ..|  ..|  ..|  ..|  ..
  Khassab       |  ..|  ..|  ..|  ..|  ..
  Minor Canals  |  ..|  ..|  ..|  ..|  ..
                +----+----+----+----+----
  Total right   |    |    |    |    |
  bank          |  ..|  ..|  ..|  ..|  ..
                +----+----+----+----+----
  Total both    |    |    |    |    |
  banks         |  ..|  ..|  ..|  ..|  ..
  ==============+====+====+====+====+====

_Canal discharges between Assuan and Cairo._

  ==============+====+====+====+====+====+====+====+====+====+====+
  Left bank     |1660|1690|1810|1760|1640|1650|1960|1760|1870|1810|
  Right bank    | 380| 450| 480| 470| 430| 430| 470| 430| 410| 370|
                +----+----+----+----+----+----+----+----+----+----+
  Total         |2040|2140|2290|2230|2070|2080|2330|2190|2280|2180|
  --------------+----+----+----+----+----+----+----+----+----+----+
  Assuân gauge  | 7·0| 7·3| 7·4| 7·3| 7·2| 7·5| 7·6| 7·4| 7·1| 7·3|
  Assiout gauge | 6·2| 6·2| 6·4| 6·3| 6·2| 6·3| 6·5| 6·5| 6·6| 6·6|
  Cairo gauge   | 5·8| 5·6| 5·9| 6·0| 6·0| 5·8| 6·0| 6·0| 6·1| 6·3|
  ==============+====+====+====+====+====+====+====+====+====+====+

  ==============+====+====+====+====+====
  Left bank     |  ..|  ..|  ..|  ..|  ..
  Right bank    |  ..|  ..|  ..|  ..|  ..
                +----+----+----+----+----
  Total         |  ..|  ..|  ..|  ..|  ..
  --------------+----+----+----+----+----
  Assuân gauge  | 7·1| 7·3| 6·9| 6·3| 6·0
  Assiout gauge | 6·4| 6·5| 6·7| 6·7|  ..
  Cairo gauge   | 6·2| 6·1| 6·4| 6·5| 2·7
  ==============+====+====+====+====+====


TABLE L.--_Calculated Cairo gauges corresponding to Assuân gauges if
basin irrigation were to be changed into perennial irrigation._

                                       1874.
  ============+======+========+======+======+======+======+===============
    Date at   |Gauges|  Dis-  |Water |Trough| Dis- |Gauges|    Date at
    Assuân.   |  at  | charges| con- |  of  |charge|  at  |     Cairo.
              | As-  |   at   | sump-| Nile |  at  |Cairo.|
              | suân.| Assuân.| tion |Assuân|Cairo.|      |
              |      |        |Assuân|  to  |      |      |
              |      |        |  to  |Cairo.|      |      |
              |      |        |Cairo.|      |      |      |
  ------------+------+--------+------+------+------+------+---------------
  August     5|  6·9 |  7600  |-1020 |-1000 |  5580|  5·8 |10th August.
     „      10|  7·4 |  8600  |   do |   do |  6580|  6·4 |15th    „
     „      15|  8·5 | 11500  |   do |   do |  9480|  7·8 |20th    „
     „      20|  8·6 | 11800  |   do |   do |  9780|  7·9 |25th    „
     „      25|  8·7 | 12100  |   do |   do | 10080|  8·1 |31st    „
              |      |        |      |      +------+------+---------------
     „      31|  8·7 | 12100  |   do |   do | 10080|  8·2 | 5th September.
  ------------+------+--------+------+------+      |      |
  September  5|  9·0 | 12800  |   do |   do | 10780|  8·3 |10th    „
      „     10|  8·8 | 11800  |   do |    0 | 10780|  8·4 |15th    „
      „     15|  8·7 | 11500  |   do | +500 | 10980|  8·5 |20th    „
      „     20|  8·4 | 10600  |   do |   do | 10080|  8·2 |25th    „
      „     25|  8·4 | 10600  |   do |   do | 10080|  8·2 |30th    „
              |      |        |      |      +------+------+---------------
      „     30|  8·2 | 10050  |   do |   do |  9430|  7·9 | 5th October.
  ------------+------+--------+------+------+      |      |
  October    5|  7·9 |  9300  |   do |   do |  8780|  7·6 |10th    „
     „      10|  7·6 |  8600  |   do | +700 |  8280|  7·4 |15th    „
     „      15|  7·2 |  7800  |   do |   do |  7480|  7·0 |20th    „
     „      20|  6·6 |  6600  |   do |   do |  6280|  6·3 |25th    „
     „      25|  6·2 |  6000  |   do |   do |  5680|  5·9 |31st    „
              |      |        |      |      +------+------+---------------
     „      31|  5·6 |  5100  |   do |   do |  4780|  5·3 | 5th November.
  ------------+------+--------+------+------+      |      |
  November   5|  5·2 |  4500  |   do |   do |  4780|  4·3 |10th    „
  ============+======+========+======+======+======+======+===============


TABLE LI.--_Calculated Cairo gauges corresponding to Assuân gauges if
basin irrigation were to be changed into perennial irrigation._

                                       1877.
  ============+======+========+======+======+======+======+===============
    Date at   |Gauges|  Dis-  |Water |Trough| Dis- |Gauges|    Date at
    Assuân.   |  at  | charges| con- |  of  |charge|  at  |     Cairo.
              | As-  |   at   | sump-| Nile |  at  |Cairo.|
              | suân.| Assuân.| tion |Assuân|Cairo.|      |
              |      |        |Assuân|  to  |      |      |
              |      |        |  to  |Cairo.|      |      |
              |      |        |Cairo.|      |      |      |
  ------------+------+--------+------+------+------+------+---------------
  August     5|  4·8 |  4200  | -800 | -300 | 3100 |  3·9 |10th August.
     „      10|  5·4 |  5100  |-1020 |   do | 3780 |  4·6 |15th    „
     „      15|  5·8 |  5700  |   do |   do | 4380 |  5·0 |20th    „
     „      20|  6·4 |  6500  |   do |   do | 5180 |  5·5 |25th    „
     „      25|  6·1 |  5800  |   do |   do | 4480 |  5·1 |31st    „
              |      |        |      |      +------+------+---------------
     „      31|  6·2 |  6000  |   do |   do | 4680 |  5·2 | 5th September.
  ------------+------+--------+------+------+      |      |
  September  5|  6·3 |  6200  |   do |   do | 4880 |  5·3 |10th    „
       „    10|  6·1 |  5800  |   do | +200 | 4980 |  5·5 |15th    „
       „    15|  6·1 |  5700  |   do |   do | 4880 |  5·4 |20th    „
       „    20|  6·0 |  5700  |   do |   do | 4880 |  5·4 |25th    „
       „    25|  6·3 |  6200  |   do |   do | 5380 |  5·6 |30th    „
              |      |        |      |      +------+------+---------------
       „    30|  6·1 |  5800  |   do |   do | 4980 |  5·4 | 5th October.
  ------------+------+--------+------+------+      |      |
  October    5|  5·6 |  5100  |   do |   do | 4280 |  5·0 |10th    „
      „     10|  5·2 |  4500  |   do |   do | 3680 |  4·6 |15th    „
      „     15|  4·9 |  4200  | -950 |   do | 3450 |  4·4 |20th    „
      „     20|  4·6 |  3800  | -900 |   do | 3100 |  4·0 |25th    „
      „     25|  4·5 |  3600  | -850 |   do | 2950 |  3·9 |31st    „
              |      |        |      |      +------+------+---------------
      „     31|  4·0 |  3100  | -800 |   do | 2500 |  3·5 | 5th November.
  ------------+------+--------+------+------+      |      |
  November   5|  3·7 |  2800  | -700 |   do | 2300 |  3·3 |10th    „
  ============+======+========+======+======+======+======+===============


TABLE LII.--_Calculated Cairo gauges corresponding to Assuân gauges if
basin irrigation were to be changed into perennial irrigation._

                                    1878
  ============+======+========+======+======+======+======+===============
    Date at   |Gauges|  Dis-  |Water |Trough| Dis- |Gauges|    Date at
    Assuân.   |  at  | charges| con- |  of  |charge|  at  |     Cairo.
              | As-  |   at   | sump-| Nile |  at  |Cairo.|
              | suân.| Assuân.| tion |Assuân|Cairo.|      |
              |      |        |Assuân|  to  |      |      |
              |      |        |  to  |Cairo.|      |      |
              |      |        |Cairo.|      |      |      |
  ------------+------+--------+------+------+------+------+---------------
  August     5|  5·6 |  5400  |-1020 | -800 | 3580 |  4·4 |10th August.
     „      10|  5·3 |  6500  |   do |   do | 4680 |  5·2 |15th   „
     „      15|  7·2 |  8200  |   do |   do | 6380 |  6·3 |20th   „
     „      20|  7·5 |  8600  |   do |   do | 6780 |  6·5 |25th   „
     „      25|  8·1 | 10000  |   do |   do | 8180 |  7·3 |31st   „
              |      |        |      |      +------+------+---------------
     „      31|  7·6 |  8800  |   do | +800 | 8580 |  7·5 | 5th September.
  ------------+------+--------+------+------+      |      |
  September  5|  8·1 | 10300  |   do | -600 | 8580 |  7·5 |10th    „
      „     10|  8·5 | 11500  |   do |   do | 9880 |  8·0 |15th    „
      „     15|  8·9 | 12800  |   do |   do |11180 |  8·5 |20th    „
      „     20|  8·9 | 12500  |   do |   do |10880 |  8·4 |25th    „
      „     25|  9·0 | 12800  |   do |   do |11180 |  8·5 |30th    „
              |      |        |      |      +------+------+---------------
      „     30|  9·1 | 13200  |   do |   do |11580 |  8·6 | 5th October.
  ------------+------+--------+------+------+      |      |
  October    5|  8·9 | 12100  |   do | +400 |11480 |  8·6 |10th    „
     „      10|  8·5 | 10900  |   do | +800 |10680 |  8·4 |15th    „
     „      15|  7·9 |  9300  |   do |   do | 9080 |  8·0 |20th    „
     „      20|  7·6 |  8600  |   do |   do | 3380 |  7·4 |25th    „
     „      25|  7·4 |  8200  |   do |   do | 7980 |  7·2 |31st    „
              |      |        |      |      +------+------+---------------
     „      31|  6·8 |  7000  |   do |   do | 6780 |  6·6 | 5th November.
  ------------+------+--------+------+------+      |      |
  November   5|  6·3 |  6200  |   do |   do | 5980 |  6·1 |10th    „
  ============+======+========+======+======+======+======+===============


Appendix L

GAUGES OF THE NILE AND ITS TRIBUTARIES


TABLE LIII.--_Lake Victoria gauges at Jinja near the Ripon Falls._

  =========+=================+=================+=================+
   Months. |       1898      |       1899      |       1900      |
           +-----+-----+-----+-----+-----+-----+-----+-----+-----+
           |Maxi-|Mini-|Mean.|Maxi-|Mini-|Mean.|Maxi-|Mini-|Mean.|
           | mum.| mum.|     | mum.| mum.|     | mum.| mum.|     |
  ---------+-----+-----+-----+-----+-----+-----+-----+-----+-----+
  January  |  .. |  .. |  .. | 0·95| 0·89| 0·90| 0·44| 0·34| 0·39|
  February |  .. |  .. |  .. | 0·91| 0·84| 0·87| 0·43| 0·33| 0·39|
  March    |  .. |  .. |  .. | 0·89| 0·83| 0·85| 0·43| 0·33| 0·38|
  April    |  .. |  .. |  .. | 0·94| 0·83| 0·84| 0·48| 0·38| 0·42|
  May      |  .. |  .. | 1·05| 1·05| 0·85| 0·94| 0·48| 0·42| 0·45|
  June     |  .. |  .. | 0·96| 1·02| 0·86| 0·93| 0·47| 0·41| 0·45|
  July     |  .. |  .. | 0·99| 0·91| 0·79| 0·86| 0·46| 0·44| 0·45|
  August   |  .. |  .. | 0·96| 0·85| 0·56| 0·64| 0·46| 0·43| 0·45|
  September| 0·99| 0·93| 0·95| 0·56| 0·43| 0·48| 0·43| 0·30| 0·38|
  October  | 0·98| 0·91| 0·95| 0·43| 0·33| 0·38| 0·30| 0·17| 0·24|
  November | 0·99| 0·91| 0·95| 0·36| 0·33| 0·35| 0·19| 0·11| 0·16|
  December | 0·99| 0·98| 0·95| 0·38| 0·33| 0·35| 0·38| 0·15| 0·26|
  ---------+-----+-----+-----+-----+-----+-----+-----+-----+-----+
  Mean.    |  .. |  .. |  .. |  .. |  .. | 0·70|  .. |  .. | 0·37|
  =========+=====+=====+=====+=====+=====+=====+=====+=====+=====+

  =========+=================+=================+=================+
   Months. |       1901      |       1902      |       1903      |
           +-----+-----+-----+-----+-----+-----+-----+-----+-----+
           |Maxi-|Mini-|Mean.|Maxi-|Mini-|Mean.|Maxi-|Mini-|Mean.|
           | mum.| mum.|     | mum.| mum.|     | mum.| mum.|     |
  ---------+-----+-----+-----+-----+-----+-----+-----+-----+-----+
  January  | 0·41| 0·28| 0·35| 0·40| 0·34| 0·38| 0·57| 0·33| 0·42|
  February | 0·38| 0·30| 0·36| 0·43| 0·36| 0·39| 0·71| 0·62| 0·68|
  March    | 0·58| 0·42| 0·48| 0·41| 0·34| 0·37| 0·77| 0·66| 0·71|
  April    | 0·89| 0·46| 0·66| 0·44| 0·39| 0·43| 0·93| 0·72| 0·78|
  May      | 0·95| 0·81| 0·89| 0·60| 0·44| 0·54| 1·10| 0·84| 1·00|
  June     | 0·93| 0·74| 0·83| 0·55| 0·45| 0·50| 1·22| 1·07| 1·15|
  July     | 0·76| 0·61| 0·68| 0·46| 0·41| 0·44| 1·37| 1·17| 1·24|
  August   | 0·64| 0·46| 0·57| 0·45| 0·38| 0·42| 1·22| 1·00| 1·14|
  September| 0·51| 0·27| 0·39| 0·41| 0·37| 0·39| 1·03| 0·95| 0·98|
  October  | 0·51| 0·33| 0·45| 0·40| 0·32| 0·35| 1·17| 0·99| 1·07|
  November | 0·36| 0·29| 0·33| 0·41| 0·33| 0·37| 1·27| 1·05| 1·16|
  December | 0·43| 0·34| 0·40| 0·43| 0·28| 0·36| 1·24| 1·12| 1·16|
  ---------+-----+-----+-----+-----+-----+-----+-----+-----+-----+
  Mean.    |  .. |  .. | 0·53|  .. |  .. | 0·41|  .. |  .. | 0·96|
  =========+=====+=====+=====+=====+=====+=====+=====+=====+=====+

  =========+=================
   Months. |       1904
           +-----+-----+-----
           |Maxi-|Mini-|Mean.
           | mum.| mum.|
  ---------+-----+-----+-----
  January  |  .. |  .. | ..
  February |  .. |  .. | ..
  March    |  .. |  .. | ..
  April    |  .. |  .. | ..
  May      |  .. |  .. | ..
  June     |  .. |  .. | ..
  July     |  .. |  .. | ..
  August   |  .. |  .. | ..
  September|  .. |  .. | ..
  October  |  .. |  .. | ..
  November |  .. |  .. | ..
  December |  .. |  .. | ..
  ---------+-----+-----+-----
  Mean.    |  .. |  .. | ..
  =========+=====+=====+=====


TABLE LIV.--_Wadelai gauges._

  =====+=====+====+====+====+====+====+====+====+====+====+====+====+====
  Year.|Date.|Jan.|Feb.|Mar.|Apr.|May.|Jun.|Jul.|Aug.|Sep.|Oct.|Nov.|Dec.
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1901 |   1 |  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|0·74
       |   5 |  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|0·66
       |  10 |  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|0·69|0·66
       |  15 |  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|0·69|0·64
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |  20 |  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|0·67|0·62
       |  25 |  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|0·75|0·58
       |  30 |  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|0·74|0·58
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |Mean |  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..|0·72|0·63
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1902 |   1 |0·58|0·30|0·25|0·13|0·10|0·15|0·10|0·20|0·29|0·33|0·71|0·86
       |   5 |0·55|0·32|0·28|0·09|0·13|0·15|0·11|0·19|0·43|0·41|0·71|0·89
       |  10 |0·53|0·27|0·25|0·09|0·14|  ..|0·08|0·25|0·51|0·38|0·61|0·91
       |  15 |0·43|0·22|0·18|0·08|0·16|0·10|0·18|0·18|0·33|0·52|0·81|0·86
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |  20 |0·38|0·25|0·20|0·10|0·25|0·08|0·27|0·20|0·33|0·66|0·86|0·85
       |  25 |0·36|0·28|0·20|0·11|0·23|0·13|0·20|0·33|0·30|0·51|0·75|0·82
       |  30 |0·32|  ..|0·13|0·10|0·18|0·10|0·19|0·28|0·33|0·65|0·86|0·76
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |Mean |0·44|0·26|0·20|0·09|0·17|0·12|0·15|0·24|0·37|0·49|0·76|0·85
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1903 |   1 |0·76|0·69|0·58|0·53|0·53|0·56|1·02|1·07|1·07|1·60|1·70|1·93
       |   5 |0·76|0·69|0·61|0·51|0·56|0·61|0·84|1·12|1·07|1·60|1·70|1·93
       |  10 |0·76|0·67|0·57|0·53|0·56|0·76|0·89|1·07|1·12|1·60|1·83|1·93
       |  15 |0·74|0·61|0·56|0·46|0·58|0·79|0·84|1·17|1·37|1·60|1·83|1·93
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |  20 |0·74|0·63|0·55|0·51|0·66|0·79|0·89|1·14|1·45|1·57|1·88|1·93
       |  25 |0·74|0·61|0·53|0·48|0·61|0·81|1·12|1·12|1·52|1·65|1·90|1·90
       |  30 |0·76|  ..|0·53|0·53|0·61|1·00|1·07|1·07|1·60|1·68|1·93|1·90
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |Mean |0·75|0·64|0·56|0·50|0·59|0·77|0·95|1·12|1·32|1·63|1·84|1·92
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1904 |   1 |1·90|1·90|1·70|1·70|  ..|1·74|  ..|  ..|  ..|  ..|  ..|  ..
       |   5 |1·90|1·90|1·73|1·70|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..
       |  10 |1·90|1·87|1·69|1·70|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..
       |  15 |1·90|1·78|1·68|1·71|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |  20 |1·90|1·73|1·68|1·71|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..
       |  25 |1·90|1·74|1·68|1·74|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..
       |  30 |1·90|  ..|1·71|1·74|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |Mean |1·90|1·80|1·69|1·71|  ..|  ..|  ..|  ..|  ..|  ..|  ..|  ..
  =====+=====+====+====+====+====+====+====+====+====+====+====+====+====


TABLE LV.--_Gondokoro gauges._

                               1901
  =====+======+=====+=====+=====+=====+=====+=====+=====+=======
  Date.|Month.|Date.| May.|June.|July.| Au- | Sep-|Date.|Month.
       |      |     |     |     |     |gust.| tem-|     |
       |      |     |     |     |     |     | ber.|     |
  -----+------+-----+-----+-----+-----+-----+-----+-----+------
       |  Jan.|     |     |     |     |     |     |     |  Oct.
   1   |  ·22 |   1 | 0·34| 0·44| 0·33| 0·34| 0·63|  1  | 0·41
   5   |  ·20 |   2 | 0·34| 0·42| 0·33| 0·34| 0·63|  5  | 0·39
  10   |  ·18 |   3 | 0·38| 0·43| 0·32| 0·35| 0·64| 10  | 0·51
  15   |  ·17 |   4 | 0·40| 0·43| 0·33| 0·34| 0·63| 15  | 0·60
  20   |  ·12 |   5 | 0·71| 0·45| 0·33| 0·43| 0·63| 20  | 0·71
       |      +-----+-----+-----+-----+-----+-----+     |
  25   |  ·12 |   6 | 0·56| 0·43| 0·60| 0·54| 0·69| 25  | 0·67
  30   |  ·12 |   7 | 0·52| 0·41| 0·47| 0·44| 0·63| 30  | 0·69
       +------+     |     |     |     |     |     |     +------
  Mean |  ·15 |   8 | 0·46| 0·41| 0·37| 0·47| 0·67|Mean | 0·60
  -----+------|     |     |     |     |     |     +-----+------
       |  Feb.|   9 | 0·42| 0·41| 0·59| 0·64| 0·67|     |  Nov.
   1   |  ·12 |  10 | 0·42| 0·41| 0·39| 0·63| 0·67|  1  | 0·64
       |      +-----+-----+-----+-----+-----+-----+     |
   5   |  ·12 |  11 | 0·42| 0·41| 0·35| 0·62| 0·65|  5  | 0·67
  10   |  ·12 |  12 | 0·56| 0·41| 0·34| 0·46| 0·66| 10  | 0·64
  15   |  ·11 |  13 | 0·38| 0·40| 0·34| 0·41| 0·63| 15  | 0·49
  20   |  ·10 |  14 | 0·38| 0·40| 0·56| 0·48| 0·63| 20  | 0·57
  25   |  ·10 |  15 | 0·40| 0·40| 0·52| 0·46| 0·56| 25  | 0·59
       |      +-----+-----+-----+-----+-----+-----+     |
  28   |  ·09 |  16 | 0·36| 0·40| 0·56| 0·48| 0·47| 30  | 0·60
       +------+     |     |     |     |     |     |     +------
  Mean |  ·11 |  17 | 0·34| 0·40| 0·61| 1·09| 0·43|Mean | 0·61
  -----+------+     |     |     |     |     |     +-----+------
       | March|  18 | 0·36| 0·40| 0·43| 1·09| 0·41|     |  Dec.
   1   |  ·11 |  19 | 0·34| 0·40| 0·35| 0·62| 0·39|  1  | 0·61
   5   |  ·10 |  20 | 0·34| 0·40| 0·35| 0·46| 0·36|  5  | 0·59
       |      +-----+-----+-----+-----+-----+-----+     |
  10   |  ·10 |  21 | 0·36| 0·40| 0·36| 0·44| 0·43| 10  |  0·57
  15   |  ·12 |  22 | 0·46| 0·40| 0·34| 0·72| 0·45| 15  |  0·53
  20   |  ·26 |  23 | 0·40| 0·40| 0·34| 0·52| 0·49| 20  |  0·49
  25   |  ·22 |  24 | 0·40| 0·40| 0·35| 0·54| 0·45| 25  |  0·47
  30   |  ·27 |  25 | 0·42| 0·36| 0·34| 0·43| 0·45| 30  |  0·45
       +------+-----+-----+-----+-----+-----+-----+     +-------
  Mean |  ·18 |  26 | 0·52| 0·42| 0·36| 1·24| 0·43|Mean |  0·52
  -----+------+     |     |     |     |     |     +-----+-------
       | April|  27 | 0·42| 0·54| 0·35| 0·67| 0·41|     |
   1   | 0·08 |  28 | 0·46| 0·40| 0·35| 0·66| 0·39|     |
   5   | 0·08 |  29 | 0·46| 0·34| 0·35| 0·62| 0·41|     |
  10   | 0·14 |  30 | 0·46| 0·34| 0·35|     | 0·41|     |
       |      +-----+-----+-----+-----+-----+-----+     |
  15   | 0·32 |  31 | 0·46|  .. | 0·35|  .. |  .. |     |
       |      +-----+-----+-----+-----+-----+-----+     |
  20   | 0·44 |Mean | 0·43| 0·40| 0·40| 0·57| 0·53|     |
       |      +-----+-----+-----+-----+-----+-----+     |
  25   | 0·42 |     |     |     |     |     |     |     |
  30   | 0·30 |     |     |     |     |     |     |     |
       +------+     |     |     |     |     |     |     |
  Mean | 0·25 |     |     |     |     |     |     |     |
  =====+======+=====+=====+=====+=====+=====+=====+=====+=======
                               1902
  =====+======+=====+=====+=====+=====+=====+=====+=====+=======
  Date.|Month.|Date.| May.|June.|July.| Au- | Sep-|Date.| Month.
       |      |     |     |     |     |gust.| tem-|     |
       |      |     |     |     |     |     | ber.|     |
  -----+------+-----+-----+-----+-----+-----+-----+-----+-------
       | Jan. |     |     |     |     |     |     |     |  Oct.
    1  | 0·45 |  1  | 0·19| 0·06|-0·01| 0·44| 0·54|  1  |  0·48
    5  | 0·43 |  2  | 0·20| 0·08| 0·02| 0·36| 0·52|  5  |  0·26
   10  | 0·43 |  3  | 0·22| 0·14| 0·02| 0·44| 0·74| 10  |  0·54
   15  | 0·47 |  4  | 0·26| 0·11| 0·04| 0·54| 1·04| 15  |  0·79
   20  | 0·45 |  5  | 0·24| 0·09| 0·71| 0·49| 0·94| 20  |  0·80
       |      +-----+-----+-----+-----+-----+-----+     |
   25  | 0·41 |  6  | 0·19| 0·09| 0·34| 0·42| 0·90| 25  |  0·76
   30  | 0·41 |  7  | 0·19|-0·03| 0·08| 0·48| 1·24| 30  |  0·99
       +------+     |     |     |     |     |     |     +-------
  Mean | 0·43 |  8  | 0·14| 0·04| 0·04| 1·54| 0·96|Mean |  0·71
  -----+------+     |     |     |     |     |     +-----+-------
       | Feb. |  9  | 0·16| 0·09| 0·04| 1·09| 0·84|     |  Nov.
    1  | 0·39 | 10  | 0·18| 0·06|-0·01| 1·52| 1·04|  1  |  1·07
       |      +-----+-----+-----+-----+-----+-----+     |
    5  | 0·36 | 11  | 0·34| 0·03|-0·01| 1·49| 0·99|  5  |  0·77
   10  | 0·35 | 12  | 0·60| 0·07| 0·04| 1·44| 0·77| 10  |  0·84
   15  | 0·33 | 13  | 0·48| 0·02| 0·04| 1·42| 0·74| 15  |   --
   20  | 0·33 | 14  | 0·44|-0·01| 0·24| 1·46| 0·84| 20  |  1·23
   25  | 0·36 | 15  | 0·51|-0·06| 0·04| 1·42| 0·96| 25  |  0·99
       |      +-----+-----+-----+-----+-----+-----+     |
   28  | 0·40 | 16  | 0·45|-0·03| 0·02| 1·42| 1·28| 30  |  0·96
       +------+     |     |     |     |     |     |     +-------
  Mean | 0·35 | 17  | 0·39|-0·01|-0·01| 1·44| 0·94|Mean |  1·00
  -----+------+     |     |     |     |     |     +-----+-------
       |March | 18  | 0·53|-0·08|-0·01| 1·38| 0·94|     |  Dec.
    1  | 0·34 | 19  | 0·57|-0·06| 0·09| 1·32| 0·84|  1  |  0·94
    5  | 0·36 | 20  | 0·64|-0·03| 0·12| 1·38| 0·89|  5  |  0·94
   10  | 0·38 | 21  | 0·46|-0·06| 0·40| 1·46| 0·82| 10  |  0·92
   15  | 0·46 | 22  | 0·39|-0·09| 0·87| 1·52| 0·76| 15  |  0·89
   20  | 0·50 | 23  | 0·30|-0·14| 0·48| 1·62| 0·62| 20  |  0·85
   25  | 0·34 | 24  | 0·27|+0·04| 0·30| 1·74| 0·64| 25  |  0·81
   30  | 0·26 | 25  | 0·24| 0·01| 0·26| 1·52| 0·91| 30  |  0·74
       +------+-----+-----+-----+-----+-----+-----+     +-------
  Mean | 0·40 | 26  | 0·19| 0·02| 0·24| 0·54| 0·66|Mean |  0·87
  -----+------+     |     |     |     |     |     +-----+-------
       |April | 27  | 0·16|-0·06| 0·22| 0·94| 0·62|     |
    1  | 0·14 | 28  | 0·14|-0·04| 0·22| 0·74| 0·54|     |
    5  | 0·13 | 29  | 0·11|-0·01| 0·46| 0·70| 0·54|     |
   10  | 0·04 | 30  | 0·07|-0·02| 0·54|  .. | 0·57|     |
       |      +-----+-----+-----+-----+-----+-----+     |
   15  |-0·01 | 31  | 0·04|  .. | 0·58| 0·60|  .. |     |
       |      +-----+-----+-----+-----+-----+-----+     |
   20  | 0·19 |Mean | 0·30| 0·01| 0·19| 1·09| 0·82|     |
       |      +-----+-----+-----+-----+-----+-----+     |
   25  | 0·05 |     |     |     |     |     |     |     |
   30  | 0·13 |     |     |     |     |     |     |     |
       +------+     |     |     |     |     |     |     |
  Mean | 0·07 |     |     |     |     |     |     |     |
  =====+======+=====+=====+=====+=====+=====+=====+=====+=======
                               1903
  =====+======+=====+=====+=====+=====+=====+=====+=====+=======
  Date.|Month.|Date.| May.|June.|July.| Au- | Sep-|Date.| Month.
       |      |     |     |     |     |gust.| tem-|     |
       |      |     |     |     |     |     | ber.|     |
  -----+------+-----+-----+-----+-----+-----+-----+-----+-------
       | Jan. |     |     |     |     |     |     |     | Oct.
    1  | 0·74 |   1 | 0·72| 1·15| 1·37| 1·55| 1·86|  1  | 2·18
    5  | 0·71 |   2 | 1·70| 1·06| 1·38| 1·57| 1·82|  5  | 2·11
   10  | 0·66 |   3 | 0·68| 1·06| 1·46| 1·65| 1·90| 10  | 2·12
   15  | 0·63 |   4 | 0·68| 1·06| 1·43| 1·65| 2·54| 15  | 2·45
   20  | 0·63 |   5 | 0·70| 1·00| 1·39| 1·72| 2·24| 20  | 2·06
       |      +-----+-----+-----+-----+-----+-----+     |
   25  | 0·61 |   6 | 0·98| 1·10| 1·44| 1·61| 2·23| 25  | 2·20
   30  | 0·63 |   7 | 0·92| 1·61| 1·46| 1·73| 2·71| 30  | 2·20
       +------+     |     |     |     |     |     |     +-------
  Mean | 0·65 |   8 | 0·85| 1·36| 1·51| 2·16| 2·50|Mean | 2·16
  -----+------+     |     |     |     |     |     +-----+-------
       | Feb. |   9 | 0·89| 1·35| 1·49| 2·08| 2·33|     | Nov.
    1  | 0·62 |  10 | 1·06| 1·10| 1·46| 2·03| 2·29|  1  | 2·20
       |      +-----+-----+-----+-----+-----+-----+     |
    5  | 0·61 |  11 | 0·80| 1·07| 1·41| 2·50| 2·24|  5  | 2·13
   10  | 0·63 |  12 | 1·42| 1·06| 1·45| 2·03| 2·16| 10  | 2·05
   15  | 0·58 |  13 | 1·48| 1·09| 1·56| 2·07| 2·09| 15  | 1·92
   20  | 0·59 |  14 | 0·85| 1·08| 1·49| 1·86| 2·07| 20  | 1·91
   25  | 0·56 |  15 | 0·85| 1·06| 1·35| 2·12| 2·20| 25  | 1·90
       |      +-----+-----+-----+-----+-----+-----+     |
   28  | 0·53 |  16 | 0·89| 1·55| 1·40| 1·99| 2·23| 30  | 1·77
       +------+     |     |     |     |     |     |     +-------
  Mean | 0·59 |  17 | 0·86| 1·47| 1·35| 1·90| 2·37|Mean | 1·96
  -----+------+     |     |     |     |     |     +-----+-------
       | March|  18 | 0·85| 1·44| 1·40| 1·93| 2·48|     | Dec.
    1  | 0·51 |  19 | 0·85| 1·40| 1·40| 1·86| 2·57|  1  | 1·77
    5  | 0·51 |  20 | 0·86| 1·44| 1·40| 1·85| 2·70|  5  | 0·89
       |      +-----+-----+-----+-----+-----+-----+     |
   10  | 0·51 |  21 | 0·86| 1·40| 1·41| 1·90| 2·76| 10  | 0·86
   15  | 0·51 |  22 | 1·35| 1·52| 1·52| 1·95| 2·76| 15  | 0·81
   20  | 0·52 |  23 | 1·52| 1·40| 1·61| 1·86| 2·96| 20  | 0·79
   25  | 0·51 |  24 | 1·02| 1·40| 1·52| 1·82| 2·96| 25  | 0·79
   30  | 0·50 |  25 | 1·00| 1·37| 1·55| 1·83| 2·58| 30  | 0·76
       +------+-----+-----+-----+-----+-----+-----+     +-------
  Mean | 0·51 |  26 | 0·97| 1·27| 1·56| 2·20| 2·45|Mean | 0·88
  -----+------+     |     |     |     |     |     +-----+-------
       |April.|  27 | 1·03| 1·30| 1·67| 2·16| 2·33|     |
    1  | 0·50 |  28 | 1·00| 1·32| 1·61| 2·07| 2·23|     |
    5  | 0·48 |  29 | 0·90| 1·43| 1·65| 1·82| 2·20|     |
   10  | 0·48 |  30 | 0·89| 1·35| 1·63| 1·88| 2·18|     |
       |      +-----+-----+-----+-----+-----+-----+     |
   15  | 0·55 |  31 | 0·91|  .. | 1·52| 1·90|   ..|     |
       |      +-----+-----+-----+-----+-----+-----+     |
   20  | 0·57 |Mean | 0·95| 1·27| 1·48| 1·91| 2·36|     |
       |      +-----+-----+-----+-----+-----+-----+     |
   25  | 0·57 |     |     |     |     |     |     |     |
   30  | 0·64 |     |     |     |     |     |     |     |
       +------+     |     |     |     |     |     |     |
  Mean | 0·53 |     |     |     |     |     |     |     |
  =====+======+=====+=====+=====+=====+=====+=====+=====+=======
               1904
  =====+======+=====+=====+=====
  Date.|Month.|Date.| May.|June.
       |      |     |     |
       |      |     |     |
  -----+------+-----+-----+-----
    1  | 0·79 |  1  | 0·68| 0·90
    5  | 0·78 |  2  | 0·68| 0·90
   10  | 0·78 |  3  | 0·70| 0·90
   15  | 0·76 |  4  | 0·70| 0·90
   20  | 0·84 |  5  | 0·70| 0·90
       |      +-----+-----+-----
   25  | 0·84 |  6  | 0·70| 0·88
   30  | 0·82 |  7  | 0·68| 0·84
       +------+     |     |
  Mean.| 0·80 |  8  | 0·68| 0·80
  -----+------+     |     |
       | Feb. |  9  | 0·68| 0·76
    1  | 0·82 | 10  | 0·68| 0·76
       |      +-----+-----+-----
    5  | 0·80 | 11  | 0·78| 0·74
   10  | 0·74 | 12  | 0·78| 0·72
   15  | 0·72 | 13  | 0·84| 0·74
   20  | 0·70 | 14  | 0·84| 0·72
   25  | 0·68 | 15  | 0·80| 0·72
       |      +-----+-----+-----
   28  | 0·74 | 16  | 0·80| 0·70
       +------+     |     |
  Mean.| 0·73 | 17  | 0·76| 0·70
  -----+------+     |     |
       |March | 18  | 0·78| 0·70
    1  | 0·68 | 19  | 0·80| 0·74
    5  | 0·70 | 20  | 0·80| 0·82
       |      +-----+-----+-----
   10  | 0·66 | 21  | 0·84| 0·70
   15  | 0·66 | 22  | 0·88| 0·70
   20  | 0·66 | 23  | 0·88| 0·74
   25  | 0·84 | 24  | 0·88| 0·78
   30  | 0·90 | 25  | 1·00| 0·74
       +------+-----+-----+-----
  Mean.| 0·71 | 26  | 0·88| 0·88
  -----+------+     |     |
       |April.| 27  | 0·84| 0·78
    1  | 0·74 | 28  | 0·84| 0·84
    5  | 0·72 | 29  | 0·84| 0·82
   10  | 0·72 | 30  | 0·90| 0·88
       |      +-----+-----+-----
   15  | 0·80 | 31  |  .. |  ..
       |      +-----+-----+-----
   20  | 0·84 |Mean.| 0·79| 0·79
   25  | 0·74 +-----+-----+-----
   30  |  ..  |     |     |
       +------+     |     |
  Mean.| 0·77 |     |     |
  =====+======+=====+=====+=====


TABLE LVI.--_Mongalla gauges._

                               1903
  =====+======+=====+=====+=====+=====+=====+=====+=====+========
  Date.|Month.|Date.| May.|June.|July.| Au- | Sep-|Date.| Month.
       |      |     |     |     |     |gust.| tem-|     |
       |      |     |     |     |     |     | ber.|     |
  -----+------+-----+-----+-----+-----+-----+-----+-----+--------
       |Janu- |     |     |     |     |     |     |     |October.
    1  |ary.  |  1  |     | 1·65| 1·93| 2·19| 2·52|  1  |  2·83
    5  |      |  2  |     | 1·47| 1·89| 2·50| 2·45|  5  |  2·83
   10  |      |  3  |     | 1·47| 1·79| 2·34| 2·58| 10  |  2·81
   15  |      |  4  |     | 1·51| 1·86| 2·30| 2·73| 15  |  2·91
   20  |      |  5  |     | 1·75| 1·91| 2·28| 2·85| 20  |  2·80
       |      |     +-----+-----+-----+-----+-----+     |
   25  |      |  6  |     | 1·96| 1·86| 2·21| 2·90| 25  |  2·80
   30  |      |  7  |     | 1·75| 1·82| 2·14| 3·02| 30  |  2·87
       +------+     |     |     |     |     |     |     +--------
  Mean.|      |  8  |     | 1·91| 1·75| 2·12| 3·16|Mean.|  2·83
  -----+------+     |     |     |     |     |     +-----+--------
       |Febru-|  9  |     | 1·89| 1·84| 2·59| 3·14|Nov. |
    1  |ary.  | 10  |     | 1·89| 1·84| 2·63| 3·08| 1   |  2·84
       |      +-----+-----+-----+-----+-----+-----+     |
    5  |      | 11  |     | 1·58| 1·82| 2·73| 2·90|  5  |  2·81
   10  |      | 12  |     | 1·58| 1·75| 2·73| 2·84| 10  |  2·81
   15  |      | 13  |     | 1·61| 1·75| 2·68| 2·82| 15  |  2·79
   20  |      | 14  |     | 1·61| 1·93| 2·66| 2·82| 20  |  2·66
   25  |      | 15  |     | 1·98| 1·86| 2·63| 2·82| 25  |  2·35
       |      +-----+-----+-----+-----+-----+-----+     |
   28  |      | 16  |     | 1·98| 1·86| 2·52| 2·84| 30  |  2·27
       +------+     |     |     |     |     |     |     +--------
  Mean.|      | 17  |     | 2·10| 1·89| 2·56| 2·92|Mean.|  2·64
  -----+------+     |     |     |     |     |     +-----+--------
       |March.| 18  |     | 2·10| 1·82| 2·56| 3·06|Dec. |
    1  |      | 19  |     | 2·10| 1·96| 2·63| 3·12| 1   |  2·26
    5  |      | 20  |     | 1·82| 1·93| 2·63| 3·18| 5   |  2·21
       |      +-----+-----+-----+-----+-----+-----+     |
   10  |      | 21  |     | 1·95| 2·00| 2·59| 3·30| 10  |  2·17
   15  |      | 22  |     | 1·89| 2·00| 2·65| 3·40| 15  |  2·14
   20  |      | 23  |     | 1·86| 2·05| 2·66| 3·52| 20  |  2·10
   25  |      | 24  |     | 1·82| 2·05| 2·63| 3·54| 25  |  2·03
   30  |      | 25  |     | 1·75| 2·07| 2·61| 3·42| 30  |  2·02
       +------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|      | 26  |     | 1·72| 2·07| 2·49| 3·32|Mean.|  2·13
  -----+------+     |     |     |     |     |     +-----+--------
       |April.|     |     |     |     |     |     |     |
    1  | 0·83 | 27  |     | 1·75| 2·12| 2·52| 3·18|     |
    5  | 0·87 | 28  |     | 1·68| 2·13| 2·52| 3·05|     |
   10  | 0·90 | 29  |     | 1·89| 2·16|  .. | 3·00|     |
   15  | 0·89 | 30  |     | 1·93| 2·21|  .. | 2·92|     |
       |      +-----+-----+-----+-----+-----+-----+     |
   20  | 0·96 | 31  |     |  .. | 2·21|     |     |     |
       |      +-----+-----+-----+-----+-----+-----+     |
   25  | 1·14 |Mean.|     | 1·82| 1·96| 2·49| 2·97|     |
       |      +-----+-----+-----+-----+-----+-----+     |
   30  | 0·99 |     |     |     |     |     |     |     |
       +------+     |     |     |     |     |     |     |
  Mean.| 0·92 |     |     |     |     |     |     |     |
  =====+======+=====+=====+=====+=====+=====+=====+=====+========
                               1904
  =====+======+=====+=====+=====+=====+=====+=====+=====+========
  Date.|Month.|Date.| May.|June.|July.| Au- | Sep-|Date.| Month.
       |      |     |     |     |     |gust.| tem-|     |
       |      |     |     |     |     |     | ber.|     |
  -----+------+-----+-----+-----+-----+-----+-----+-----+--------
       | Janu-|     |     |     |     |     |     |     |Octo-
       |  ary.|     |     |     |     |     |     |     |ber.
    1  | 2·03 |  1  | 1·91| 2·17|     |     |     |     |
    5  | 2·00 |  2  | 1·89| 2·24|     |     |     |     |
   10  | 1·98 |  3  | 1·89| 2·17|     |     |     |     |
   15  | 1·97 |  4  | 1·89| 2·21|     |     |     |     |
   20  | 1·96 |  5  | 1·89| 2·17|     |     |     |     |
       |      +-----+-----+-----+-----+-----+-----+     |
   25  | 1·92 |  6  | 1·96| 2·17|     |     |     |     |
   30  | 1·91 |  7  | 1·89| 2·14|     |     |     |     |
       +------+     |     |     |     |     |     |     |
  Mean.| 1·97 |  8  | 1·89| 2·10|     |     |     |     |
  -----+------+     |     |     |     |     |     |     |
       |Febru-|     |     |     |     |     |     |     |
       | ary. |  9  | 1·89| 2·07|     |     |     |     |
    1  | 1·91 | 10  | 1·89| 2·03|     |     |     |     |
       |      +-----+-----+-----+-----+-----+-----+     |
    5  | 1·89 | 11  | 1·96| 2·00|     |     |     |     |
   10  | 1·86 | 12  | 2·03| 2·00|     |     |     |     |
   15  | 1·82 | 13  | 2·10| 2·00|     |     |     |     |
   20  | 1·82 | 14  | 2·03| 2·00|     |     |     |     |
   25  | 1·82 | 15  | 2·07| 2·00|     |     |     |     |
       |      +-----+-----+-----+-----+-----+-----+     |
   28  | 1·82 | 16  | 2·03| 1·96|     |     |     |     |
       +------+     |     |     |     |     |     |     |
  Mean.| 1·85 | 17  | 2·03| 1·96|     |     |     |     |
  -----+------+     |     |     |     |     |     |     |
       |March.| 18  | 2·03| 1·96|     |     |     |     |
    1  | 1·82 | 19  | 2·03| 2·10|     |     |     |     |
    5  | 1·81 | 20  | 2·07| 2·03|     |     |     |     |
       |      +-----+-----+-----+-----+-----+-----+     |
   10  | 1·79 | 21  | 2·07| 2·00|     |     |     |     |
   15  | 1·82 | 22  | 2·17| 1·98|     |     |     |     |
   20  | 1·77 | 23  | 2·17| 1·98|     |     |     |     |
   25  | 1·79 | 24  | 2·17| 2·00|     |     |     |     |
   30  | 1·96 | 25  | 2·21| 2·07|     |     |     |     |
       +------+-----+-----+-----+-----+-----+-----+     |
  Mean.| 1·82 | 26  | 2·21| 2·07|     |     |     |     |
  -----+------+     |     |     |     |     |     |     |
       |April.|     |     |     |     |     |     |     |
    1  | 1·93 | 27  | 2·17| 2·10|     |     |     |     |
    5  | 1·82 | 28  | 2·14| 2·10|     |     |     |     |
   10  | 1·82 | 29  | 2·12| 2·07|     |     |     |     |
   15  | 1·93 | 30  | 2·10| 2·03|     |     |     |     |
   20  | 2·07 +-----+-----+-----+-----+-----+-----+     |
   25  | 1·96 | 31  | 2·21|     |     |     |     |     |
       |      |     |     |     |     |     |     |     |
   30  | 1·89 |Mean.| 2·03| 2·07|     |     |     |     |
       +------+     +-----+-----+-----+-----+-----+     |
  Mean.| 1·91 |     |     |     |     |     |     |     |
  =====+======+=====+=====+=====+=====+=====+=====+=====+========


TABLE LVII.--_Sobat River gauges at Nasser._

  =====+=====+====+====+====+====+====+====+====+====+====+====+====+====
  Year.|Date.|Jan.|Feb.|Mar.|Apr.|May.|Jun.|Jul.|Aug.|Sep.|Oct.|Nov.|Dec.
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1903 |   1 | .. | .. | .. | .. | .. | .. | .. | .. | .. | .. |6·30| ..
       |   5 | .. | .. | .. | .. | .. | .. | .. | .. | .. | .. |6·30| ..
       |  10 | .. | .. | .. | .. | .. | .. | .. | .. | .. | .. |6·28| ..
       |  15 | .. | .. | .. | .. | .. | .. | .. | .. | .. | .. |6·24| ..
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |  20 | .. | .. | .. | .. | .. | .. | .. | .. | .. | .. |6·18| ..
       |  25 | .. | .. | .. | .. | .. | .. | .. | .. | .. |6·46|6·14| ..
       |  30 | .. | .. | .. | .. | .. | .. | .. | .. | .. |6·29| .. | ..
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | Mean| .. | .. | .. | .. | .. | .. | .. | .. | .. | .. |6·23| ..
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1904 |   1 |5·11|2·02|1·26|2·00|1·96|4·59| .. | .. | .. | .. | .. | ..
       |   5 |4·99|1·92|1·34|2·00|2·26|4·68| .. | .. | .. | .. | .. | ..
       |  10 |4·49|1·82|1·40|1·82|2·88|4·82| .. | .. | .. | .. | .. | ..
       |  15 |3·88|1·60|1·86|1·90|3·42|5·02| .. | .. | .. | .. | .. | ..
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |  20 |2·92|1·50|2·14|2·38|4·10| .. | .. | .. | .. | .. | .. | ..
       |  25 |2·24|1·36|1·88|2·38| .. | .. | .. | .. | .. | .. | .. | ..
       |  30 |2·10| .. |2·00|2·00| .. | .. | .. | .. | .. | .. | .. | ..
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | Mean|3·43|1·64|1·71|2·07| .. | .. | .. | .. | .. | .. | .. | ..
  =====+=====+====+====+====+====+====+====+====+====+====+====+====+====


TABLE LVIII.--_Sobat River gauges at Dulaib Hilla._

  =====+=====+====+====+====+====+=====+===+====+====+====+====+====+====
  Year.|Date.|Jan.|Feb.|Mar.|Apr.|May.|Jun.|Jul.|Aug.|Sep.|Oct.|Nov.|Dec.
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1903 |   1 | .. | .. | .. | .. |0·00|1·11|1·71|2·30|2·80|3·26|3·48|3·52
       |   5 | .. | .. | .. | .. |0·09|1·22|1·80|2·39|2·86|3·27|3·48|3·52
       |  10 | .. | .. | .. | .. |0·28|1·36|1·87|2·45|2·93|3·36|3·49|3·53
       |  15 | .. | .. | .. | .. |0·40|1·53|1·95|2·52|3·05|3·42|3·49|3·54
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |  20 | .. | .. | .. | .. |0·62|1·56|2·08|2·57|3·11|3·44|3·50|3·53
       |  25 | .. | .. | .. | .. |0·81|1·65|2·18|2·70|3·16|3·45|3·50|3·51
       |  30 | .. | .. | .. | .. |1·00|1·70|2·28|2·74|3·26|3·47|3·51|3·45
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | Mean| .. | .. | .. | .. |0·47|1·46|1·99|2·54|3·03|3·40|3·49|3·51
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1904 |   1 |3·42|1·92|0·93|0·88|0·81|1·56|2·00| .. | .. | .. | .. | ..
       |   5 |3·36|1·65|0·87|0·88|0·73|1·65| .. | .. | .. | .. | .. | ..
       |  10 |3·19|1·42|0·88|0·86|0·86|1·67| .. | .. | .. | .. | .. | ..
       |  15 |3·04|1·24|0·91|0·78|0·99|1·72| .. | .. | .. | .. | .. | ..
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |  20 |2·74|1·12|0·97|0·81|1·21|1·83| .. | .. | .. | .. | .. | ..
       |  25 |2·36|1·00|1·00|0·90|1·39|1·90| .. | .. | .. | .. | .. | ..
       |  30 |2·01| .. |0·91|0·84|1·49|1·98| .. | .. | .. | .. | .. | ..
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | Mean|2·77|1·30|0·92|0·85|1·08|1·76| .. | .. | .. | .. | .. | ..
  =====+=====+====+====+====+====+====+====+====+====+====+====+====+====


TABLE LIX.-- _White Nile gauges at Tewfikieh._

  =====+=====+====+====+====+====+=====+===+====+====+====+====+====+====
  Year.|Date.|Jan.|Feb.|Mar.|Apr.|May.|Jun.|Jul.|Aug.|Sep.|Oct.|Nov.|Dec.
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1903 |   1 | .. | .. | .. | .. |0·24|1·19|1·71|2·11|2·76|3·47|3·53|3·56
       |   5 | .. | .. | .. | .. |0·24|1·30|1·78|2·15|2·86|3·55|3·54|3·58
       |  10 | .. | .. | .. | .. |0·34|1·42|1·88| .. |3·07|3·39|3·54|3·58
       |  15 | .. | .. | .. | .. |0·53|1·51|1·89| .. |3·20|3·41|3·55|3·59
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |  20 | .. | .. | .. |0·22|0·74|1·58|2·01| .. |3·26|3·46|3·56|3·59
       |  25 | .. | .. | .. |0·24| .. |1·61|2·09| .. |3·37|3·50|3·55|3·58
       |  30 | .. | .. | .. |0·24| .. |1·69|2·16| .. |3·46|3·52|3·56|3·57
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | Mean| .. | .. | .. | .. | .. |1·48|1·94| .. |3·15|3·44|3·55|3·58
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1904 |   1 |3·57|2·07|0·97|0·91|0·84|1·56| .. | .. | .. | .. | .. | ..
       |   5 |3·54|1·76|0·91|0·91|0·74|1·67| .. | .. | .. | .. | .. | ..
       |  10 |3·48|1·48|0·92|0·89|0·86|1·69| .. | .. | .. | .. | .. | ..
       |  15 |3·36|1·25|0·94|0·81|1·02|1·74| .. |2·79| .. | .. | .. | ..
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |  20 |3·10|1·09|1·00|0·84|1·25|1·87| .. |2·87| .. | .. | .. | ..
       |  25 |2·69|1·07|1·03|0·93|1·43|1·94| .. |2·92| .. | .. | .. | ..
       |  30 |2·23| .. |0·97|0·84|1·53|2·02| .. |2·98| .. | .. | .. | ..
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | Mean|3·16|1·37|0·96|0·88|1·11|1·79| .. | .. | .. | .. | .. | ..
  =====+=====+=========+====+====+====+====+====+====+====+====+====+====


TABLE LX.--_Duem gauges._

  =====+=====+====+====+====+====+====+====+====+====+====+====+====+====
  Year.|Date.|Jan.|Feb.|Mar.|Apr.|May.|Jun.|Jul.|Aug.|Sep.|Oct.|Nov.|Dec.
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1901 |  1  | .. |0·91|0·66|0·43|0·61|0·59|1·43|2·88|4·10|3·40|2·40|2·12
       |  5  | .. |0·90|0·66|0·40|0·64|0·66|1·44|3·18|4·28|3·36|2·35|2·10
       | 10  | .. |0·88|0·60|0·46|0·62|0·77|1·54|3·38|4·16|2·90|2·33|2·00
       | 15  | .. |0·85|0·51|0·27|0·51|0·91|1·78|3·80|4·22|2·70|2·28|1·86
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | 20  | .. |0·80|0·47|0·36|0·52|1·08|1·96|4·12|4·08|2·85|2·30|1·80
       | 25  | .. |0·75|0·45|0·46|0·52|1·22|1·98|4·12|3·70|2·38|2·30|1·64
       | 30  | .. |0·68|0·45|0·58|0·51|1·32|2·48|4·04|3·46|2·42|2·14|1·46
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |Mean | .. |0·82|0·54|0·42|0·56|0·94|1·80|3·65|4·00|2·84|2·30|1·85
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1902 |  1  |1·38|0·78|0·60|0·59|0·56|0·77|1·28|2·12|3·52|3·50|2·36| ..
       |  5  |1·24|0·74|0·58|0·62|0·52|0·81|1·40|2·20|3·49|3·48|2·26| ..
       | 10  |1·16|0·73|0·51|0·58|0·49|0·95|1·48|2·55|3·62|3·36|2·20| ..
       | 15  |1·07|0·66|0·54|0·58|0·54|1·04|1·60|2·82|3·72|3·00|2·14|2·02
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | 20  |0·95|0·60|0·60|0·55|0·59|1·08|1·72|2·91|3·72|2·68|2·11|1·99
       | 25  |0·90|0·60|0·66|0·61|0·66|1·14|1·89|3·17|3·58|2·57|2·00|2·01
       | 30  |0·80|0·60|0·62|0·57|0·74|1·24|2·10|3·52|3·51|2·45|2·00|1·98
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |Mean |1·07|0·67|0·59|0·58|0·58|1·00|1·64|2·75|3·60|3·00|2·15| ..
  -----+-----+----+-+--+----+----+----+----+----+----+----+----+----+----
  1903 |  1  |1·90|1·04|0·72|0·41|0·38|0·74|1·31|1·27|4·33|4·18|3·13|2·34
       |  5  |1·90|1·02|0·71|0·40|0·34|0·82|1·34|2·62|4·30|4·01|3·02|2·16
       | 10  |1·75|0·99|0·64|0·42|0·33|0·98|1·54|3·18|4·48|3·82|2·82|1·96
       | 15  |1·45|0·89|0·55|0·41|0·36|1·07|1·74|3·70|4·38|3·62|2·66|1·92
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | 20  |1·39|0·88|0·48|0·38|0·41|1·20|1·80|3·84|4·18|3·36|2·56|1·84
       | 25  |1·20|0·80|0·47|0·37|0·52|1·28|2·03|4·12|4·28|3·40|2·42|1·76
       | 30  |1·06|0·77|0·42|0·37|0·61|1·33|2·24|4·22|4·22|3·41|2·36|1·70
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |Mean |1·52|0·90|0·57|0·40|0·42|1·06|1·70|3·42|4·30|3·70|2·70|1·95
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1904 |  1  |1·70|1·38|0·88|0·26|0·19|0·24|0·50|2·00|2·64| .. | .. | ..
       |  5  |1·66|1·32|0·66|0·30|0·18|0·30|0·51|2·90|2·80| .. | .. | ..
       | 10  |1·62|1·28|0·50|0·28|0·16|0·40|0·70|3·40|3·00| .. | .. | ..
       | 15  |1·60|1·20|0·35|0·25|0·15|0·41|0·95|3·15| .. | .. | .. | ..
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | 20  |1·54|1·14|0·30|0·22|0·14|0·48|1·30|2·70| .. | .. | .. | ..
       | 25  |1·46|1·00|0·28|0·21|0·22|0·49|1·55|2·45| .. | .. | .. | ..
       | 30  |1·40|0·94|0·26|0·19|0·24|0·50|1·90|2·64| .. | .. | .. | ..
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |Mean |1·57|1·18|0·46|0·24|0·18|0·40|1·06|2·75| .. | .. | .. | ..
  =====+=====+====+====+====+====+====+====+====+====+====+====+====+====


TABLE LXI.--_Wad Medani gauges._

                                 1901
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       | January |  .. |  .. |  .. |  .. |  .. |  .. |     |October.
       |         |  .. |  .. |  .. |  .. |  .. |  .. |  1  |  ..
       |         |  .. |  .. |  .. |  .. |  .. |  .. |  5  |  ..
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 10  |  ..
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 15  |  ..
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 20  |  ..
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 25  |  ..
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 30  |  ..
       |         |     |     |     |     |     |     |     +--------
       |         |  .. |  .. |  .. |  .. |  .. |  .. |Mean.|
       |         |     |     |     |     |     |     +-----+--------
       |February |  .. |  .. |  .. |  .. |  .. |  .. |     |Novemb.
       |         |  .. |  .. |  .. |  .. |  .. |  .. |  1  | 4·49
       |         |  .. |  .. |  .. |  .. |  .. |  .. |  5  | 4·19
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 10  | 3·85
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 15  | 3·53
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 20  | 3·25
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 25  | 3·07
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 30  | 3·01
       |         |     |     |     |     |     |     |     +--------
       |         |  .. |  .. |  .. |  .. |  .. |  .. |Mean.| 3·58
       |         |     |     |     |     |     |     +-----+--------
       | March   |  .. |  .. |  .. |  .. |  .. |  .. |     |Decemb.
       |         |  .. |  .. |  .. |  .. |  .. |  .. |  1  | 2·89
       |         |  .. |  .. |  .. |  .. |  .. |  .. |  5  | 2·67
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 10  | 2·47
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 15  | 2·33
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 20  | 2·19
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 25  | 2·05
       |         |  .. |  .. |  .. |  .. |  .. |  .. | 30  | 1·91
       |         |     |     |     |     |     |     |     +--------
       |         |  .. |  .. |  .. |  .. |  .. |  .. |Mean.| 2·33
       |         |     |     |     |     |     |     +-----+--------
       | April   |  .. |  .. |  .. |  .. |  .. |  .. |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
                                 1902
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
   1   |   1·89  |  1  | 0·39| 1·59| 3·80| 7·56| 9·62|   1 | 9·94
   5   |   1·81  |  2  | 0·33| 2·11| 3·80| 7·86|10·12|   5 | 9·30
  10   |   1·69  |  3  | 0·33| 2·11| 3·70| 7·94|10·42|  10 | 8·00
  15   |   1·61  |  4  | 0·37| 2·07| 3·80| 8·32|10·32|  15 | 7·38
  20   |   1·55  |  5  | 0·39| 2·03| 4·16| 8·42|10·30|  20 | 7·08
       |         +-----+-----+-----+-----+-----+-----+     |
  25   |   1·49  |  6  | 0·41| 1·97| 4·46| 8·56|10·10|  25 | 6·68
  30   |   1·39  |  7  | 0·39| 1·91| 4·68| 8·76|10·40|  30 | 6·14
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   1·62  |  8  | 0·39| 1·97| 4·64| 8·86|10·50|Mean.| 7·65
  -----+---------+     |     |     |     |     |     +-----+--------
       |February.|  9  | 0·37| 2·25| 4·56| 9·00|10·40|     | Nov.
   1   |    1·37 | 10  | 0·35| 2·15| 4·38| 9·10|10·40|   1 | 5·90
       |         +-----+-----+-----+-----+-----+-----+     |
   5   |    1·31 | 11  | 0·41| 2·00| 4·48| 9·14|10·28|   5 | 5·66
  10   |    1·21 | 12  | 0·48| 1·77| 4·28| 9·16|10·60|  10 | 5·24
  15   |    1·13 | 13  | 0·51| 1·67| 4·56| 9·14|10·70|  15 | 4·94
  20   |    1·07 | 14  | 0·61| 1·61| 4·70| 9·02|10·48|  20 | 4·74
  25   |    1·03 | 15  | 0·77| 1·65| 4·86| 8·96|10·28|  25 | 4·60
       |         +-----+-----+-----+-----+-----+-----+     |
  28   |    0·99 | 16  | 0·89| 1·99| 4·80| 8·66|10·32|  30 | 4·28
       +---------+     |     |     |     |     |     |     +--------
  Mean.|    1·15 | 17  | 0·87| 2·57| 5·10| 8·66|10·32|Mean.| 5·02
  -----+---------+     |     |     |     |     |     +-----+--------
       |March.   | 18  | 1·01| 2·97| 5·20| 8·96|10·00|     | Dec.
   1   |    0·98 | 19  | 0·95| 3·27| 5·40| 9·48|10·30|   1 | --
   5   |    0·91 | 20  | 0·93| 3·39| 5·48|10·08|10·26|   5 | 4·00
       |         +-----+-----+-----+-----+-----+-----+     |
  10   |    0·79 | 21  | 0·71| 3·39| 5·42|10·00|10·00|  10 | 3·73
  15   |    0·87 | 22  | 0·61| 3·19| 5·66| 9·66| 9·80|  15 | 3·54
  20   |    1·01 | 23  | 0·65| 3·04| 5·70| 9·46| 9·80|  20 | 3·40
  25   |    0·84 | 24  | 0·61| 2·94| 5·66| 9·52|10·00|  25 | 3·18
  30   |    0·67 | 25  | 0·57| 3·04| 5·76| 9·92|10·10|  30 | 2·94
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|    0·87 | 26  | 0·61| 3·89| 5·74|10·26| 9·90|Mean.| 3·51
  -----+---------+     |     |     |     |     |     +-----+--------
       |April.   |     |     |     |     |     |     |     |
   1   |    0·63 | 27  | 0·65| 4·29| 5·72|10·46| 9·95|     |
   5   |    0·55 | 28  | 0·71| 4·24| 6·36|10·52|10·00|     |
  10   |    0·43 | 29  | 0·91| 4·24| 6·79|10·32|10·26|     |
  15   |    0·43 | 30  | 0·11| 4·28| 7·06|10·02|10·26|     |
       |         +-----+-----+-----+-----+-----+-----+     |
  20   |    0·51 | 31  | 0·21|     | 7·28| 9·72|     |     |
       |         +-----+-----+-----+-----+-----+-----+     |
  25   |    0·57 |Mean.| 0·56| 2·65| 5·09| 9·21|10·20|     |
       |         +-----+-----+-----+-----+-----+-----+     |
  30   |    0·41 |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|    0·50 |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
                                 1903
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |         |     |     |     |     |     |     |     |
       |January. |     |     |     |     |     |     |     |October.
   1   |    2·88 |  1  | 0·96| 3·15| 4·71| 7·75|11·02|  1  | 9·48
   5   |    2·70 |  2  | 0·96| 3·25| 5·27| 9·11|10·68|  5  | 8·84
  10   |    2·56 |  3  | 0·94| 3·85| 5·61| 9·81|10·44| 10  | 8·42
  15   |    2·46 |  4  | 0·92| 4·05| 5·81|10·11|10·40| 15  | 7·94
  20   |    2·36 |  5  | 0·90| 3·61| 5·85|10·11|10·50| 20  | 8·84
       |         +-----+-----+-----+-----+-----+-----+     |
  25   |    2·26 |  6  | 0·88| 3·65| 6·10|10·07|10·64| 25  | 8·25
  30   |    2·16 |  7  | 0·88| 3·49| 6·23|10·21|10·56| 30  | 7·33
       +---------+     |     |     |     |     |     |     +--------
  Mean.|    2·42 |  8  | 0·90| 3·41| 6·45|10·15|10·50|Mean.| 8·41
  -----+---------+     |     |     |     |     |     |-----+--------
       |February.|  9  | 0·86| 3·63| 6·55| 9·99|10·74|     | Nov.
   1   |    2·12 | 10  | 0·82| 3·79| 6·57| 9·89|10·52|  1  | 7·19
       |         +-----+-----+-----+-----+-----+-----+     |
   5   |    2·04 | 11  | 0·84| 3·90| 6·81|10·19|10·46|  5  | 6·68
  10   |    2·00 | 12  | 0·86| 4·20| 7·03|10·59|10·40| 10  | 6·12
  15   |    1·90 | 13  | 0·88| 4·30| 7·13|10·71|10·06| 15  | 5·70
  20   |    1·84 | 14  | 0·92| 4·42| 6·77|10·57| 9·96| 20  | 5·55
  25   |    1·72 | 15  | 0·98| 4·64| 6·74|10·32| 9·92| 25  | 5·14
       |         +-----+-----+-----+-----+-----+-----+     |
  28   |    1·70 | 16  | 1·02| 4·82| 6·57|10·49| 9·94| 30  | 4·96
       +---------+     |     |     |     |     |     |     +--------
  Mean.|    1·91 | 17  | 1·06| 4·70| 6·91|10·41| 9·92|Mean.| 5·83
  -----+---------+     |     |     |     |     |     |-----+--------
       |March.   | 18  | 1·14| 4·62| 7·05|10·49| 9·96|     | Dec.
   1   |    1·68 | 19  | 1·26| 4·52| 7·05|10·49|10·12|  1  | 4·92
   5   |    1·60 | 20  | 1·40| 4·32| 7·39|10·73|10·32|  5  | 4·80
       |         +-----+-----+-----+-----+-----+-----+     |
  10   |    1·52 | 21  | 1·66| 4·30| 8·01|10·71|10·42| 10  | 4·54
  15   |    1·44 | 22  | 1·76| 4·28| 7·97|10·71|10·56| 15  | 4·40
  20   |    1·34 | 23  | 1·92| 4·28| 7·81|10·47|10·52| 20  | 4·10
  25   |    1·32 | 24  | 2·06| 4·25| 7·87|10·39|10·46| 25  | 3·84
  30   |    1·30 | 25  | 2·20| 4·51| 7·75|10·39|10·32| 30  | 3·60
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|    1·44 | 26  | 2·74| 4·31| 7·77|10·47|10·18|Mean.| 4·28
  -----+---------+     |     |     |     |     |     |-----+--------
       |April.   | 27  | 1·51| 4·21| 7·80|10·41| 9·72|     |
   1   |    1·24 | 28  | 3·43| 4·17| 7·73|10·61| 9·42|     |
   5   |    1·10 | 29  | 3·39| 4·13| 7·77|10·67| 9·24|     |
  10   |    1·10 | 30  | 3·34| 4·41| 7·67|10·80| 9·22|     |
       |         +-----+-----+-----+-----+-----+-----+     |
  15   |    1·08 | 31  | 3·25|     | 7·70|10·92|     |     |
       |         +-----+-----+-----+-----+-----+-----+     |
  20   |    1·04 |Mean.| 1·50| 4·10| 6·92|10·28|10·23|     |
       |         +-----+-----+-----+-----+-----+-----+     |
  25   |    0·98 |     |     |     |     |     |     |     |
  30   |    0·98 |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|    1·06 |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
                                 1904
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|     |
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |
   1   |    3·64 |  1  | 1·50| 2·36| 4·24| 9·60| 9·50|     |
   5   |    3·56 |  2  | 1·48| 2·50| 4·58|10·30| 9·58|     |
  10   |    3·48 |  3  | 1·66| 2·88| 4·82|10·10| 9·50|     |
  15   |    3·36 |  4  | 1·66| 3·32| 5·22| 9·90| 9·50|     |
  20   |    3·15 |  5  | 1·64| 3·40| 5·52| 9·70| 9·40|     |
       |         +-----+-----+-----+-----+-----+-----+     |
  25   |    3·08 |  6  | 1·64| 3·28| 5·52| 9·60| 9·30|     |
  30   |    2·80 |  7  | 1·62| 3·24| 5·22| 9·40| 9·30|     |
       +---------+     |     |     |     |     |     |     |
  Mean.|    3·28 |  8  | 1·64| 3·08| 4·92| 9·50| 9·20|     |
  -----+---------+     |     |     |     |     |     |     |
       |February.|  9  | 1·56| 2·98| 4·82| 9·50| 9·20|     |
   1   |    2·76 | 10  | 1·62| 3·00| 4·96| 9·40| 9·29|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   5   |    2·58 | 11  | 1·66| 2·86| 5·80| 9·30| 9·30|     |
  10   |    2·46 | 12  | 1·76| 2·78| 6·18| 9·20| 9·30|     |
  15   |    2·22 | 13  | 1·80| 2·78| 6·10| 9·20| 9·40|     |
  20   |    2·06 | 14  | 2·00| 2·46| 6·48| 9·20| 9·44|     |
  25   |    1·86 | 15  | 2·00| 2·34| 7·12| 9·00|     |     |
       |         +-----+-----+-----+-----+-----+-----+     |
  28   |    1·78 | 16  | 1·88| 2·32| 6·92| 8·80|     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|     2·23| 17  | 1·88| 2·30| 6·90| 8·80|     |     |
  -----+---------+     |     |     |     |     |     |     |
       |March.   | 18  | 1·82| 2·34| 6·80| 8·90|     |     |
   1   |    1·72 | 19  | 1·64| 2·34| 6·70| 8·96|     |     |
   5   |    1·70 | 20  | 1·70| 2·34| 6·80| 9·10|     |     |
       |         +-----+-----+-----+-----+-----+-----+     |
  10   |    1·64 | 21  | 1·72| 2·50| 7·10| 9·00|     |     |
  15   |    1·50 | 22  | 1·72| 2·42| 7·30| 9·10|     |     |
  20   |    1·44 | 23  | 1·68| 2·48| 7·20| 9·20|     |     |
  25   |    1·70 | 24  | 1·76| 2·52| 7·40| 9·10|     |     |
  30   |    1·80 | 25  | 1·98| 2·54| 7·50| 9·30|     |     |
       +---------+-----+-----+-----+-----+-----+-----+     |
  Mean.|    1·64 | 26  | 2·46| 2·68| 8·04| 9·72|     |     |
  -----+---------+     |     |     |     |     |     |     |
       |April.   | 27  | 2·50| 2·80| 8·22| 9·50|     |     |
   1   |    1·80 | 28  | 2·52| 2·94| 8·00| 9·30|     |     |
   5   |    1·76 | 29  | 2·48|  -- | 8·04| 9·20|     |     |
  10   |    1·64 | 30  | 2·46| 3·98| 8·70| 9·30|     |     |
       |         +-----+-----+-----+-----+-----+-----+     |
  15   |    1·58 | 31  | 2·36| 9·20| 9·30|     |     |     |
       |         +-----+-----+-----+-----+-----+-----+     |
  20   |    1·50 |Mean.| 1·86| 2·76| 6·52| 9·34|     |     |
       |         +-----+-----+-----+-----+-----+-----+     |
  25   |    1·50 |     |     |     |     |     |     |     |
  30   |    1·50 |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|    1·60 |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========


TABLE LXII.--_Khartoum gauges._

  =====+=============================+=============================+
  Date.|            1874             |            1877             |
  -----+----+----+----+----+----+----+----+----+----+----+----+----+
       | May|June|July|Aug.|Sep.|Oct.| May|June|July|Aug.|Sep.|Oct.|
  -----+----+----+----+----+----+----+----+----+----+----+----+----+
    1  | .. |1·01|2·50|5·60|7·18|6·66| .. | ·97|2·81|5·20|4·97|4·30|
    2  | .. |1·06|2·50|5·65|7·18|6·66| .. | ·97|2·77|4·79|4·97|4·30|
    3  | .. |1·22|2·50|5·78|7·22|6·55| .. | ·97|2·68|4·79|4·84|4·25|
    4  | .. |1·44|2·59|5·85|7·27|6·50| .. | ·97|2·54|4·54|4·88|4·21|
    5  | .. |1·55|2·68|6·01|7·27|6·41| .. | ·97|2·54|4·43|4·88|4·21|
  -----+----+----+----+----+----+----+----+----+----+----+----+----+
    6  | .. |1·60|2·68|6·14|7·20|6·30| .. | ·92|2·68|4·43|4·88|4·21|
    7  | .. |1·60|2·75|6·23|7·13|6·26| .. | ·01|2·86|4·66|4·97|4·12|
    8  | ·07|1·80|2·86|6·32|7·18|6·19| .. | ·88|2·95|4·84|4·97|4·12|
    9  | ·14|1·98|2·99|6·46|7·18|6·08| .. | ·83|3·04|4·84|4·97|3·98|
   10  | ·50|1·98|3·04|6·55|7·13|5·92| ·02| ·83|3·22|4·84|4·97|3·98|
  -----+----+----+----+----+----+----+----+----+----+----+----+----+
   11  | ·50|1·76|3·22|6·68|7·09|5·78| ·02| ·88|3·35|4·97|4·97|3·98|
   12  | ·86|1·76|3·31|6·77|7·13|5·65| ·02|1·24|3·35|5·06|5·00|3·98|
   13  | ·97|1·76|3·22|6·84|7·22|5·65| ·02|1·37|3·22|5·06|5·06|3·98|
   14  | ·97|1·76|3·49|6·84|7·18|5·60| ·02|1·37|3·22|5·06|5·06|3·87|
   15  | ·99|1·80|3·80|6·91|7·09|5·51| ·02|1·60|3·58|4·97|5·11|3·87|
  -----+----+----+----+----+----+----+----+----+----+----+----+----+
   16  |1·04|1·85|4·03|7·04|7·04|5·44| ·02|1·73|3·62|4·97|5·11| .. |
   17  |1·15|1·91|4·12|7·13|7·04|5·38| ·02|2·05|3·67|4·97|5·06| .. |
   18  |1·28|1·91|4·25|7·04|7·04|5·31| ·02|1·96|3·67|4·97|4·97| .. |
   19  |1·35|1·91|4·52|7·00|6·93|5·11| ·02|1·87|3·89|4·97|4·97| .. |
   20  |1·58|1·91|4·61|7·04|6·89|4·97| ·02|1·87|4·03|4·97|4·97| .. |
  -----+----+----+----+----+----+----+----+----+----+----+----+----+
   21  |1·77|1·96|4·84|6·91|6·89|4·84| ·11|1·87|4·12|4·93|4·97| .. |
   22  |1·60|1·96|4·88|7·00|6·82|4·70| ·34|1·96|4·21|4·93|4·84| .. |
   23  |1·46|2·00|4·97|6·93|6·82|4·61| ·38|2·05|4·30|5·02|4·84| .. |
   24  |1·33|2·05|5·11|6·91|6·86|4·43| ·68|2·27|4·12|5·02|4·79| .. |
   25  |1·26|2·09|5·11|6·98|6·82|4·30| ·90|2·27|4·12|5·02|4·75| .. |
  -----+----+----+----+----+----+----+----+----+----+----+----+----+
   26  |1·19|2·18|5·31|7·00|6·82|4·21|1·01|2·14|4·12|5·15|4·70| .. |
   27  |1·19|2·36|5·42|7·00|6·73|4·10|1·19|2·14|4·21|5·15|4·66| .. |
   28  |1·19|2·41|5·51|7·00|6·66|4·10|1·33|2·14|4·43|5·15|4·57| .. |
   29  |1·08|2·41|5·51|7·13|6·66|4·10|1·28|2·41|4·61|5·24|4·57| .. |
   30  |1·01|2·41|5·51|7·09|6·66|4·10|1·19|2·72|4·70|5·24|4·39| .. |
  -----+----+----+----+----+----+----+----+----+----+----+----+----+
   31  |1·01| .. |5·56|7·13| .. |4·10|1·06| .. |4·77|5·06| .. | .. |
  -----+----+----+----+----+----+----+----+----+----+----+----+----+
  Mean | .. |1·85|3·98|6·67|7·01|5·34| .. |1·54|3·60|4·95|4·89| .. |
  =====+====+====+====+====+====+====+====+====+====+====+====+====+

  =====+=============================
  Date.|            1878
  -----+----+----+----+----+----+----
       | May|June|July|Aug.|Sep.| Oct.
  -----+----+----+----+----+----+----
    1  | .. | ·02|2·63|4·30|6·46|7·20
    2  | .. | ·08|2·54|4·41|6·59|7·11
    3  | .. | ·61|2·50|4·70|6·64|7·18
    4  | .. | ·79|2·45|5·11|6·75|7·00
    5  | .. |1·13|2·45|5·31|6·82|6·82
  -----+----+----+----+----+----+----
    6  | .. |1·42|2·68|5·38|6·89|6·73
    7  | .. |1·49|2·77|5·51|6·98|6·68
    8  | .. |1·55|2·95|5·51|6·95|6·64
    9  | .. |1·89|2·97|5·51|7·04|6·59
   10  | ·05|1·62|2·97|5·51|7·09|6·55
  -----+----+----+----+----+----+----
   11  | ·05|1·62|3·04|5·85|7·16|6·64
   12  | ·05|1·62|3·29|5·94|7·25|6·35
   13  | ·05|1·64|3·44|6·03|7·25|6·30
   14  | ·05|1·73|3·51|6·05|7·31|5·26
   15  | ·05|1·80|3·51|6·12|7·31|6·19
  -----+----+----+----+----+----+----
   16  | ·05|1·80|3·51|6·21|7·36|6·12
   17  | ·05|1·78|3·51|6·21|7·40|6·08
   18  | ·05|1·73|3·51|6·14|7·47|6·03
   19  | ·05|1·69|3·76|6·08|7·47|5·96
   20  | ·05|1·71|4·03|6·01|7·56|5·92
  -----+----+----+----+----+----+----
   21  | ·05|1·80|4·07|6·01|7·58|5·78
   22  |-·02|1·76|4·05|5·78|7·58|5·72
   23  |0·0 |1·82|4·10|5·67|7·52|5·65
   24  |0·0 |2·05|4·30|5·76|7·43|5·56
   25  | ·14|2·21|4·30|5·92|7·43|5·46
  -----+----+----+----+----+----+----
   26  | ·11|2·25|4·21|5·92|7·43|5·38
   27  | ·05|2·27|4·21|5·94|7·38|5·49
   28  |-·02|2·41|4·21|6·14|7·38|5·24
   29  | ·05|2·50|4·23|6·14|7·38|5·20
   30  | ·02|2·61|4·30|6·32|7·27| ..
  -----+----+----+----+----+----+----
   31  | ·02| .. |4·30|6·44| .. | ..
  -----+----+----+----+----+----+----
  Mean | .. |1·62|3·49|5·74|6·87|6·16
  =====+====+====+====+====+====+====


TABLE LXII.--_Khartoum gauges._

                                 1901
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.| Month.  |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       | January.|     |     |     |     |     |     |     |October.
     1 |    1·51 |   1 | 0·45| 0·47| 2·35| 4·90| 6·10|   1 |  4·36
     5 |    1·44 |   2 | 0·48| 0·50| 2·58| 4·96| 6·10|   5 |  4·04
    10 |    1·30 |   3 | 0·46| 0·60| 2·75| 5·00| 6·05|  10 |  3·60
    15 |    1·17 |   4 | 0·42| 0·64| 2·70| 5·05| 5·08|  15 |  3·44
    20 |    1·05 |   5 | 0·42| 0·81| 2·57| 5·05| 6·08|  20 |  3·28
       |         +-----+-----+-----+-----+-----+-----+     |
    25 |    0·93 |   6 | 0·42| 0·82| 2·60| 5·12| 5·94|  25 |  3·12
    30 |    0·84 |   7 | 0·40| 0·85| 2·60| 5·28| 5·88|  30 |  2·91
       +---------+     |     |     |     |     |     |     +--------
  Mean.|    1·15 |   8 | 0·39| 0·84| 2·70| 5·40| 5·91|Mean.|  3·48
  -----+---------+     |     |     |     |     |     +-----+--------
       |February.|   9 | 0·37| 0·80| 2·82| 5·47| 5·95|     | Novem.
     1 |    0·84 |  10 | 0·34| 0·77| 2·90| 5·55| 5·98|   1 |  2·83
       |         +-----+-----+-----+-----+-----+-----+     |
     5 |    0·81 |  11 | 0·34| 0·98| 2·92| 5·45| 5·92|   5 |  2·67
    10 |    0·73 |  12 | 0·32| 1·28| 2·97| 5·40| 5·98|  10 |  2·43
    15 |    0·67 |  13 | 0·37| 1·39| 3·00| 5·56| 5·98|  15 |  2·28
    20 |    0·60 |  14 | 0·25| 1·51| 3·08| 5·70| 6·00|  20 |  2·16
    25 |    0·45 |  15 | 0·25| 1·70| 3·17| 5·85| 5·96|  25 |  2·00
       |         +-----+-----+-----+-----+-----+-----+     |
    28 |    0·44 |  16 | 0·25| 1·60| 3·30| 5·89| 5·93|  30 |  1·87
       +---------+     |     |     |     |     |     +-----+--------
  Mean.|    0·66 |  17 | 0·19| 1·49| 3·30| 5·96| 5·82|Mean.|  2·29
  -----+---------+     |     |     |     |     |     |-----+--------
       |March    |  18 | 0·08| 1·47| 3·38| 5·96| 5·74|     | Decem.
     1 |    0·43 |  19 | 0·08| 1·50| 3·43| 5·96| 5·56|   1 |  1·87
     5 |    0·39 |  20 | 0·14| 1·55| 3·50| 6·10| 5·40|   5 |  1·83
       |         +-----+-----+-----+-----+-----+-----+     |
    10 |    0·28 |  21 | 0·19| 1·63| 3·50| 6·05| 5·18|  10 |  1·75
    15 |    0·20 |  22 | 0·22| 1·80| 3·57| 5·98| 5·18|  15 |  1·58
    20 |    0·15 |  23 | 0·12| 2·05| 3·54| 6·01| 5·10|  20 |  1·50
    25 |    0·09 |  24 | 0·15| 2·26| 3·54| 6·05| 5·00|  25 |  1·35
    30 |    0·08 |  25 | 0·20| 2·20| 3·58| 5·97| 4·89|  30 |  1·16
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|    0·22 |  26 | 0·18| 2·00| 3·74| 5·80| 4·84|Mean.|  1·56
  -----+---------+     |     |     |     |     |     +-----+--------
       |April    |  27 | 0·25| 1·95| 4·10| 5·68| 4·78|     |
     1 |    0·06 |  28 | 0·27| 1·98| 4·28| 5·68| 4·70|     |
     5 |    0·05 |  29 | 0·34| 1·98| 4·65| 5·85| 4·58|     |
    10 |   -0·05 |  30 | 0·45| 2·10| 4·83| 5·89| 4·49|     |
       |         +-----+-----+-----+-----+-----+-----+     |
    15 |   -0·07 |  31 | 0·45|  .. | 4·85| 6·03|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    20 |    0·11 |Mean.| 0·30| 1·38| 3·32| 5·63| 5·57|     |
       |         +-----+-----+-----+-----+-----+-----+     |
    25 |    0·27 |     |     |     |     |     |     |     |
    30 |     ..  |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|    0·09 |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
                                 1902
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
     1 |  1·13   |   1 | 0·05| 0·10| 1·80| 3·34| 5·20|  1  |  5·14
     5 |  1·03   |   2 | 0·05| 0·23| 1·87| 3·52| 5·20|  5  |  4·88
    10 |  0·84   |   3 | 0·04| 0·41| 1·79| 3·62| 5·23| 10  |  4·45
    15 |  0·73   |   4 | 0·01| 0·55| 1·75| 3·71| 5·27| 15  |  3·86
    20 |  0·63   |   5 | 0·02| 0·74| 1·70| 3·79| 5·27| 20  |  3·63
       |         +-----+-----+-----+-----+-----+-----+     |
    25 |  0·54   |   6 |-0·10| 0·76| 1·76| 3·94| 5·27| 25  |  3·35
    30 |  0·50   |   7 |-0·08| 0·78| 1·85| 4·00| 5·28| 30  |  3·05
       +---------+     |     |     |     |     |     |     +--------
  Mean.|  0·75   |   8 |-0·05| 0·76| 2·03| 4·20| 5·33|Mean.|  3·97
  -----+---------+     |     |     |     |     |     |-----+--------
       |February.|   9 |-0·05| 0·75| 2·13| 4·30| 5·40|     |Novemb.
     1 |  0·48   |  10 |-0·06| 0·77| 2·16| 4·38| 5·40|  1  |  3·00
       |         +-----+-----+-----+-----+-----+-----+     |
     5 |  0·45   |  11 |-0·07| 0·84| 2·07| 4·40| 5·36|  5  |  2·84
    10 |  0·38   |  12 |-0·04| 1·00| 2·09| 4·50| 5·35| 10  |  2·60
    15 |  0·33   |  13 |-0·04| 0·84| 2·05| 4·48| 5·38| 15  |  2·44
    20 |  0·25   |  14 |-0·01| 0·78| 2·14| 4·50| 5·50| 20  |  2·24
    25 |  0·19   |  15 | 0·01| 0·75| 2·17| 4·50| 5·42| 25  |  2·18
       |         +-----+-----+-----+-----+-----+-----+     |
    28 |  0·15   |  16 | 0·04| 0·72| 2·24| 4·48| 5·40| 30  |  2·08
       +---------+     |     |     |     |     |     |     +--------
  Mean.|  0·32   |  17 | 0·03| 0·69| 2·29| 4·45| 5·40|Mean.|  2·46
  -----+---------+     |     |     |     |     |     |-----+--------
       |March.   |  18 | 0·08| 0·74| 2·33| 4·39| 5·40|     |Decemb.
     1 |  0·14   |  19 | 0·18| 0·84| 2·34| 4·50| 5·30|  1  |  2·06
     5 |  0·10   |  20 | 0·14| 1·06| 2·36| 4·61| 5·39|  5  |  1·94
       |         +-----+-----+-----+-----+-----+-----+     |
    10 |  0·09   |  21 | 0·14| 1·24| 2·52| 4·87| 5·30| 10  |  1·83
    15 |  0·07   |  22 | 0·16| 1·36| 2·54| 4·93| 5·24| 15  |  1·71
    20 |  0·15   |  23 | 0·16| 1·27| 2·56| 4·93| 5·12| 20  |  1·62
    25 |  0·19   |  24 | 0·09| 1·29| 2·62| 4·90| 5·10| 25  |  1·55
    30 |  0·07   |  25 | 0·10| 1·21| 2·64| 4·90| 5·10| 30  |  1·43
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|  0·11   |  26 | 0·11| 1·15| 2·69| 5·00| 5·10|Mean.|  1·71
  -----+---------+     |     |     |     |     |     |-----+--------
       |April.   |  27 | 0·16| 1·30| 2·69| 5·17| 5·05|     |
     1 |  0·07   |  28 | 0·14| 1·59| 2·79| 5·30| 5·03|     |
     5 | -0·02   |  29 | 0·09| 1·75| 2·94| 5·34| 5·06|     |
    10 |  0·01   |  30 | 0·10| 1·73| 2·96| 5·30| 5·16|     |
       |         +-----+-----+-----+-----+-----+-----+     |
    15 | -0·07   |  31 | 0·11|  .. | 3·24| 5·30|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    20 | -0·01   |Mean.| 0·05| 0·90| 2·30| 4·50| 5·26|     |
       |         +-----+-----+-----+-----+-----+-----+     |
    25 | -0·04   |     |     |     |     |     |     |     |
    30 |  0·01   |     |     |     |     |     |     |     |
  -----+---------+     |     |     |     |     |     |     |
  Mean.| -0·01   |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
                                 1903
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
     1 |   1·40  |   1 |-0·16| 1·05| 1·54| 3·50| 6·24|   1 | 5·50
     5 |   1·30  |   2 |-0·20| 1·05| 1·60| 3·80| 6·30|   5 | 5·40
    10 |   1·21  |   3 |-0·23| 0·98| 1·78| 4·05| 6·15|  10 | 5·15
    15 |   1·10  |   4 |-0·26| 0·98| 1·95| 4·40| 6·20|  15 | 4·50
    20 |   1·02  |   5 |-0·26| 1·16| 2·13| 4·60| 6·20|  20 | 4·48
       |         +-----+-----+-----+-----+-----+-----+     |
    25 |   0·87  |   6 |-0·23| 1·40| 2·10| 4·75| 6·15|  25 | 4·40
    30 |   0·73  |   7 |-0·23| 1·40| 2·10| 4·87| 6·12|  30 | 4·00
       +---------+     |     |     |     |     |     |     +-------
  Mean.|   1·07  |   8 |-0·23| 1·36| 2·20| 4·95| 6·15|Mean.| 4·74
  -----+---------+     |     |     |     |     |     +-----+-------
       |February.|   9 |-0·22| 1·30| 2·35| 5·06| 6·24|     |Novem.
     1 |   0·65  |  10 |-0·24| 1·25| 2·48| 5·06| 6·14|   1 | 3·85
       |         +-----+-----+-----+-----+-----+-----+     |
     5 |   0·61  |  11 |-0·28| 1·25| 2·55| 5·10| 6·15|   5 | 3·60
    10 |   0·47  |  12 |-0·24| 1·30| 2·58| 5·35| 6·05|  10 | 3·25
    15 |   0·42  |  13 |-0·26| 1·41| 2·75| 5·55| 5·96|  15 | 3·00
    20 |   0·39  |  14 |-0·25| 1·56| 2·80| 5·65| 5·90|  20 | 2·65
    25 |   0·25  |  15 |-0·26| 1·65| 2·80| 5·55| 5·86|  25 | 2·60
       |         +-----+-----+-----+-----+-----+-----+     |
    28 |   0·22  |  16 |-0·26| 1·75| 2·75| 5·70| 5·95|  30 | 2·45
       +---------+     |     |     |     |     |     |     +-------
  Mean.|   0·43  |  17 |-0·23| 1·85| 2·75| 5·80| 5·88|Mean.| 3·01
  -----+---------+     |     |     |     |     |     +-----+-------
       |  March. |  18 |-0·21| 2·00| 2·75| 5·70| 5·88|     |Decem.
     1 |   0·22  |  19 |-0·19| 1·90| 2·85| 5·80| 5·85|   1 | 2·40
     5 |   0·19  |  20 |-0·18| 1·85| 2·95| 5·80| 5·90|   5 | 2·30
       |         +-----+-----+-----+-----+-----+-----+     |
    10 |   0·13  |  21 |-0·14| 1·70| 3·05| 5·90| 5·95|  10 | 2·09
    15 |   0·08  |  22 |-0·09| 1·60| 3·25| 5·95| 6·00|  15 | 1·93
    20 |   0·04  |  23 |-0·02| 1·55| 3·40| 6·00| 6·10|  20 | 1·90
    25 |  -0·05  |  24 | 0·12| 1·55| 3·40| 6·00| 6·10|  25 | 1·88
    30 |  -0·11  |  25 | 0·26| 1·56| 3·40| 6·03| 6·08|  30 | 1·80
       +---------+-----+-----+-----+-----+-----+-----+     +-------
  Mean.|   0·06  |  26 | 0·33| 1·58| 3·42| 6·08| 6·02|Mean.| 2·01
  -----+---------+     |     |     |     |     |     +-----+-------
       |  April. |  27 | 0·40| 1·60| 3·42| 6·00| 5·85|     |
     1 |  -0·11  |  28 | 0·53| 1·61| 3·42|  .. | 5·80|     |
     5 |  -0·13  |  29 | 0·90| 1·54| 3·45|  .. | 5·60|     |
    10 |  -0·10  |  30 | 0·98| 1·54| 3·45| 6·15| 5·55|     |
       |         +-----+-----+-----+-----+-----+-----+     |
    15 |  -0·14  |  31 | 1·01|  .. | 3·45| 6·28|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    20 |  -0·12  |Mean.|-0·01| 1·47| 2·73| 5·36| 6·01|     |
       |         +-----+-----+-----+-----+-----+-----+     |
    25 |  -0·16  |     |     |     |     |     |     |     |
    30 |  -0·18  |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|  -0·13  |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
                                 1904
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |
     1 |    1·80 |  1  | 0·15| 0·61| 1·35| 5·00| 5·48| ..  |  ..
     5 |    1·78 |  2  | 0·15| 0·60| 1·55| 5·30| 5·58| ..  |  ..
    10 |    1·70 |  3  | 0·15| 0·60| 1·79| 5·50| 5·58| ..  |  ..
    15 |    1·59 |  4  | 0·10| 0·63| 2·15| 5·50| 5·54| ..  |  ..
    20 |    1·55 |  5  | 0·10| 0·70| 2·40| 5·55| 5·54| ..  |  ..
       |         +-----+-----+-----+-----+-----+-----+-----+--------
    25 |    1·50 |  6  | 0·12| 0·92| 2·68| 5·60| 5·50| ..  |  ..
    30 |    1·50 |  7  | 0·29| 1·17| 2·76| 5·58| 5·50| ..  |  ..
       +---------+     |     |     |     |     |     |     |
  Mean.|    1·59 |  8  | 0·10| 1·23| 2·76| 5·58| 5·46| ..  |  ..
  -----+---------+     |     |     |     |     |     |     |
       |February.|  9  | 0·00| 1·22| 2·74| 5·58| 5·36| ..  |  ..
     1 |    1·48 | 10  |-0·01| 1·20| 2·76| 5·58| 5·34| ..  |  ..
       |         +-----+-----+-----+-----+-----+-----+-----+--------
     5 |    1·47 | 11  |+0·05| 1·17| 2·70| 5·64| 5·34| ..  |  ..
    10 |    1·35 | 12  | 0·08| 1·16| 2·84| 5·55| 5·34| ..  |  ..
    15 |    1·15 | 13  | 0·08| 1·15| 3·05| 5·48| 5·34| ..  |  ..
    20 |    1·13 | 14  | 0·08| 1·15| 3·07| 5·48| 5·40| ..  |  ..
    25 |    1·08 | 15  | 0·10| 1·16| 3·15| 5·44| 5·40| ..  |  ..
       |         +-----+-----+-----+-----+-----+-----+-----+--------
    28 |    1·07 | 16  | 0·10| 1·16| 3·40| 5·30|  .. | ..  |  ..
       +---------+     |     |     |     |     |     |     |
  Mean.|    1·23 | 17  | 0·24| 1·16| 3·62| 5·20|  .. | ..  |  ..
  -----+---------+     |     |     |     |     |     |     |
       |March    | 18  | 0·29| 1·02| 3·63| 5·30|  .. | ..  |  ..
     1 |    1·05 | 19  | 0·31| 0·96| 3·63| 5·30|  .. | ..  |  ..
     5 |    0·80 | 20  | 0·21| 1·00| 3·63| 5·22|  .. | ..  |  ..
       |         +-----+-----+-----+-----+-----+-----+-----+--------
    10 |    0·53 | 21  | 0·19| 1·00| 3·65| 5·25|  .. | ..  |  ..
    15 |    0·37 | 22  | 0·21| 1·03| 3·75| 5·25|  .. | ..  |  ..
    20 |    0·31 | 23  | 0·24| 1·02| 3·95| 5·30|  .. | ..  |  ..
    25 |    0·25 | 24  | 0·25| 1·06| 4·00| 5·30|  .. | ..  |  ..
    30 |    0·31 | 25  | 0·30| 1·07| 4·02| 5·30|  .. | ..  |  ..
       +---------+-----+-----+-----+-----+-----+-----+-----+-------
  Mean.|    0·48 | 26  | 0·32| 1·07| 4·15| 5·45|  .. | ..  |  ..
  -----+---------+     |     |     |     |     +-----+-----+-------
       |April    | 27  | 0·40| 1·06| 4·38| 5·45|  .. |     |
     1 |    0·10 | 28  | 0·48| 1·08| 4·45| 5·62|  .. |     |
     5 |    0·29 | 29  | 0·57| 1·16| 4·45| 5·48|  .. |     |
    10 |    0·25 | 30  | 0·61| 1·20| 4·45| 5·43|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    15 |    0·18 | 31  | 0·60|  .. | 4·75| 5·45|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    20 |    0·20 |Mean.| 0·22| 1·02|  .. | 5·41|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    25 |    0·18 |     |     |     |     |     |     |     |
    30 |    0·15 |     |     |     |     |     |     |     |
  -----+---------+     |     |     |     |     |     |     |
  Mean.|    0·21 |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+=======


TABLE LXII. (continued).--_Khartoum gauges._

                                 1904
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |
     1 |    1·80 |  1  | 0·15| 0·61| 1·35| 5·00| 5·48|  .. |  ..
     5 |    1·78 |  2  | 0·15| 0·60| 1·55| 5·30| 5·58|  .. |  ..
    10 |    1·70 |  3  | 0·15| 0·60| 1·79| 5·50| 5·58|  .. |  ..
    15 |    1·59 |  4  | 0·10| 0·63| 2·15| 5·50| 5·54|  .. |  ..
    20 |    1·55 |  5  | 0·10| 0·70| 2·40| 5·55| 5·54|  .. |  ..
       |         +-----+-----+-----+-----+-----+-----+-----+-------
    25 |    1·50 |  6  | 0·12| 0·92| 2·68| 5·60| 5·50|  .. |  ..
    30 |    1·50 |  7  | 0·29| 1·17| 2·76| 5·58| 5·50|  .. |  ..
       +---------+     |     |     |     |     |     |     |
  Mean.|    1·59 |  8  | 0·10| 1·23| 2·76| 5·58| 5·46|  .. |  ..
  -----+---------+     |     |     |     |     |     |     |
       |February.|  9  | 0·00| 1·22| 2·74| 5·58| 5·36|  .. |  ..
     1 |    1·48 | 10  |-0·01| 1·20| 2·76| 5·58| 5·34|  .. |  ..
       |         +-----+-----+-----+-----+-----+-----+-----+-------
     5 |    1·47 | 11  |+0·05| 1·17| 2·70| 5·64| 5·34|  .. |  ..
    10 |    1·35 | 12  | 0·08| 1·16| 2·84| 5·55| 5·34|  .. |  ..
    15 |    1·15 | 13  | 0·08| 1·15| 3·05| 5·48| 5·34|  .. |  ..
    20 |    1·13 | 14  | 0·08| 1·15| 3·07| 5·48| 5·40|  .. |  ..
    25 |    1·08 | 15  | 0·10| 1·16| 3·15| 5·44| 5·40|  .. |  ..
       |         +-----+-----+-----+-----+-----+-----+-----+-------
    28 |    1·07 | 16  | 0·10| 1·16| 3·40| 5·30|  .. |  .. |  ..
       +---------+     |     |     |     |     |     |     |
  Mean.|    1·23 | 17  | 0·24| 1·16| 3·62| 5·20|  .. |  .. |  ..
  -----+---------+     |     |     |     |     |     |     |
       |March    | 18  | 0·29| 1·02| 3·63| 5·30|  .. |  .. |  ..
     1 |    1·05 | 19  | 0·31| 0·96| 3·63| 5·30|  .. |  .. |  ..
     5 |    0·80 | 20  | 0·21| 1·00| 3·63| 5·22|  .. |  .. |  ..
       |         +-----+-----+-----+-----+-----+-----+-----+-------
    10 |    0·53 | 21  | 0·19| 1·00| 3·65| 5·25|  .. |  .. |  ..
    15 |    0·37 | 22  | 0·21| 1·03| 3·75| 5·25|  .. |  .. |  ..
    20 |    0·31 | 23  | 0·24| 1·02| 3·95| 5·30|  .. |  .. |  ..
    25 |    0·25 | 24  | 0·25| 1·06| 4·00| 5·30|  .. |  .. |  ..
    30 |    0·31 | 25  | 0·30| 1·07| 4·02| 5·30|  .. |  .. |  ..
       +---------+-----+-----+-----+-----+-----+-----+-----+-------
  Mean.|    0·48 | 26  | 0·32| 1·07| 4·15| 5·45|  .. |  .. |  ..
  -----+---------+     |     |     |     |     +-----+-----+-------
       |April    | 27  | 0·40| 1·06| 4·38| 5·45|  .. |     |
     1 |    0·10 | 28  | 0·48| 1·08| 4·45| 5·62|  .. |     |
     5 |    0·29 | 29  | 0·57| 1·16| 4·45| 5·48|  .. |     |
    10 |    0·25 | 30  | 0·61| 1·20| 4·45| 5·43|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    15 |    0·18 | 31  | 0·60|  .. | 4·75| 5·45|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    20 |    0·20 |Mean.| 0·22| 1·02| 3·28| 5·41|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    25 |    0·18 |     |     |     |     |     |     |     |
    30 |    0·15 |     |     |     |     |     |     |     |
  -----+---------+     |     |     |     |     |     |     |
  Mean.|    0·21 |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+=======


TABLE LXIII.--_River Atbara gauges at Khasm el Girba._

                                 1903
  =====+====+====+====+====+====+====+====+====+====+====+====+====
  Date.|Jan.|Feb.|Mar.|Apr.|May.|Jun.|Jul.|Aug.|Sep.|Oct.|Nov.|Dec.
  -----+----+----+----+----+----+----+----+----+----+----+----+----
    1  | .. | .. | .. | .. | .. |1·00|2·20|4·21|4·52|2·88| .. | ..
    2  | .. | .. | .. | .. | .. |0·93|2·18|4·00|4·52|2·78| .. | ..
    3  | .. | .. | .. | .. | .. |0·85|2·15|3·56|4·60|2·78| .. | ..
    4  | .. | .. | .. | .. | .. |0·85|2·74|3·25|4·70|2·90| .. | ..
    5  | .. | .. | .. | .. | .. |0·89|2·60|3·35|4·55|2·75| .. | ..
  -----+----+----+----+----+----+----+----+----+----+----+----+----
    6  | .. | .. | .. | .. | .. |0·89|2·30|3·27|4·66|2·67| .. | ..
    7  | .. | .. | .. | .. | .. |0·86|2·10|3·30|4·58|2·50| .. | ..
    8  | .. | .. | .. | .. | .. |0·97|2·10|3·07|4·50|2·50| .. | ..
    9  | .. | .. | .. | .. | .. |1·05|2·51|3·29|4·15|2·38| .. | ..
   10  | .. | .. | .. | .. | .. |1·11|2·35|3·72|4·30|2·30| .. | ..
  -----+----+----+----+----+----+----+----+----+----+----+----+----
   11  | .. | .. | .. | .. | .. |1·00|2·65|4·61|3·89|2·22| .. | ..
   12  | .. | .. | .. | .. | .. |0·97|2·31|4·37|3·95|2·17| .. | ..
   13  | .. | .. | .. | .. | .. |0·90|2·10|4·53|3·80|2·17| .. | ..
   14  | .. | .. | .. | .. | .. |0·90|2·10|4·60|3·84|2·08| .. | ..
   15  | .. | .. | .. | .. | .. |0·93|2·65|4·85|3·71|2·05| .. | ..
  -----+----+----+----+----+----+----+----+----+----+----+----+----
   16  | .. | .. | .. | .. | .. |0·98|2·28|4·80|3·88|2·10| .. | ..
   17  | .. | .. | .. | .. | .. |1·20|2·40|4·90|4·36|2·10| .. | ..
   18  | .. | .. | .. | .. | .. |1·50|2·37|5·50|4·20| .. | .. | ..
   19  | .. | .. | .. | .. | .. |1·70|2·55|5·50|4·00|2·05| .. | ..
   20  | .. | .. | .. | .. | .. |1·98|2·74|5·75|4·12| .. | .. | ..
  -----+----+----+----+----+----+----+----+----+----+----+----+----
   21  | .. | .. | .. | .. | .. |1·88|2·83|5·47|3·80| .. | .. | ..
   22  | .. | .. | .. | .. | .. |1·70|2·70|5·12|3·45| .. | .. | ..
   23  | .. | .. | .. | .. | .. |1·90|2·70|4·82|3·30| .. | .. | ..
   24  | .. | .. | .. | .. | .. |1·84|3·00|4·54|3·25| .. | .. | ..
   25  | .. | .. | .. | .. | .. |2·20|2·62|4·35|3·10| .. | .. | ..
  -----+----+----+----+----+----+----+----+----+----+----+----+----
   26  | .. | .. | .. | .. | .. |1·93|2·53|4·20|2·89| .. | .. | ..
   27  | .. | .. | .. | .. | .. |2·24|2·60|4·80|3·42| .. | .. | ..
   28  | .. | .. | .. | .. | .. |2·20|2·76|4·55|3·10| .. | .. | ..
   29  | .. | .. | .. | .. | .. |2·43|2·80|4·55|3·13| .. | .. | ..
   30  | .. | .. | .. | .. | .. |2·20|3·29|4·75|3·05| .. | .. | ..
   31  | .. | .. | .. | .. | .. | .. |3·54|4·45| .. | .. | .. | ..
  =====+====+====+====+====+====+====+====+====+====+====+====+====
                                 1904
  =====+====+====+====+====+====+=====+====+====+====+====+====+====
  Date.|Jan.|Feb.|Mar.|Apr.|May.| Jun.|Jul.|Aug.|Sep.|Oct.|Nov.|Dec.
  -----+----+----+----+----+----+-----+----+----+----+----+----+----
    1  | .. | .. | .. | .. | .. |-1·00|1·57|3·79|2·70| .. | .. |  ..
    2  | .. | .. | .. | .. | .. |-1·00|1·89|3·85|2·65| .. | .. |  ..
    3  | .. | .. | .. | .. | .. |-0·80|1·80|3·93|2·55| .. | .. |  ..
    4  | .. | .. | .. | .. | .. |-0·56|1·93|3·90|2·90| .. | .. |  ..
    5  | .. | .. | .. | .. | .. |-0·10|2·04|4·04|3·50| .. | .. |  ..
  -----+----+----+----+----+----+-----+----+----+----+----+----+----
    6  | .. | .. | .. | .. | .. |+0·19|2·08|4·08|3·40| .. | .. |  ..
    7  | .. | .. | .. | .. | .. | 0·31|2·45|4·00|3·30| .. | .. |  ..
    8  | .. | .. | .. | .. | .. | 0·50|2·72|4·00|2·92| .. | .. |  ..
    9  | .. | .. | .. | .. | .. | 0·40|2·83|3·80|2·86| .. | .. |  ..
   10  | .. | .. | .. | .. | .. | 0·38|2·97|3·20|2·98| .. | .. |  ..
  -----+----+----+----+----+----+-----+----+----+----+----+----+----
   11  | .. | .. | .. | .. | .. | 0·35|2·88|3·93|2·60| .. | .. |  ..
   12  | .. | .. | .. | .. | .. | 0·30|2·80|2·90|2·52| .. | .. |  ..
   13  | .. | .. | .. | .. | .. | 0·30|2·80|2·71|2·85| .. | .. |  ..
   14  | .. | .. | .. | .. | .. | 0·30|3·10|2·63|2·79| .. | .. |  ..
   15  | .. | .. | .. | .. | .. | 0·29|3·03|2·70|2·09| .. | .. |  ..
  -----+----+----+----+----+----+-----+----+----+----+----+----+----
   16  | .. | .. | .. | .. | .. | 0·28|2·74|3·39| .. | .. | .. |  ..
   17  | .. | .. | .. | .. | .. | 0·32|2·91|3·39| .. | .. | .. |  ..
   18  | .. | .. | .. | .. | .. | 0·55|3·36|3·39| .. | .. | .. |  ..
   19  | .. | .. | .. | .. | .. | 0·40|3·30|3·28| .. | .. | .. |  ..
   20  | .. | .. | .. | .. | .. | 0·80|2·10|3·20| .. | .. | .. |  ..
  -----+----+----+----+----+----+-----+----+----+----+----+----+----
   21  | .. | .. | .. | .. | .. | 0·80|3·12|3·20| .. | .. | .. |  ..
   22  | .. | .. | .. | .. | .. | 0·70|3·20|3·18| .. | .. | .. |  ..
   23  | .. | .. | .. | .. | .. | 0·85|3·50|2·80| .. | .. | .. |  ..
   24  | .. | .. | .. | .. | .. | 0·96|3·72|2·83| .. | .. | .. |  ..
   25  | .. | .. | .. | .. | .. | 0·95|3·13|2·90| .. | .. | .. |  ..
  -----+----+----+----+----+----+-----+----+----+----+----+----+----
   26  | .. | .. | .. | .. | .. | 1·15|3·05|2·91| .. | .. | .. |  ..
   27  | .. | .. | .. | .. | .. | 1·30|3·36|2·96| .. | .. | .. |  ..
   28  | .. | .. | .. | .. | .. | 1·45|3·76|3·30| .. | .. | .. |  ..
   29  | .. | .. | .. | .. | .. | 1·51|3·69|3·50| .. | .. | .. |  ..
   30  | .. | .. | .. | .. | .. | 1·50|4·15|3·10| .. | .. | .. |  ..
   31  | .. | .. | .. | .. | .. |  .. |3·80|3·08| .. | .. | .. |  ..
  =====+====+====+====+====+====+=====+====+====+====+====+====+====

Zero = 10·00 metres on the gauge.


TABLE LXIV.--_Berber gauges._

                                 1901
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|Month.   |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
     1 |   2·43  |   1 | 0·96| 0·97| 2·92| 6·25| 7·80|  1  |  5·93
     5 |   2·35  |   2 | 0·98| 1·00| 2·89| 6·30| 7·79|  5  |  5·45
    10 |   2·23  |   3 | 1·00| 1·03| 3·00| 6·40| 7·82| 10  |  5·08
    15 |   2·07  |   4 | 1·02| 1·05| 3·20| 6·48| 7·75| 15  |  4·73
    20 |   1·93  |   5 | 1·04| 1·07| 3·40| 6·56| 7·70| 20  |  4·44
       |         +-----+-----+-----+-----+-----+-----+     |
    25 |   1·82  |   6 | 1·06| 1·10| 3·55| 6·79| 7·70| 25  |  4·20
    30 |   1·70  |   7 | 1·05| 1·18| 3·60| 6·67| 7·62| 30  |  4·00
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   2·06  |   8 | 1·05| 1·27| 3·65| 6·79| 7·64|Mean.|  4·74
  -----+---------+     |     |     |     |     |     +-----+--------
       |February.|   9 | 1·07| 1·36| 3·70| 6·88| 7·45|     |Novem.
     1 |   1·63  |  10 | 1·10| 1·43| 3·75| 7·09| 7·50|  1  |  3·90
       |         +-----+-----+-----+-----+-----+-----+
     5 |   1·62  |  11 | 1·09| 1·45| 3·75| 7·45| 7·63|  5  |  3·75
    10 |   1·54  |  12 | 1·07| 1·48| 3·78| 7·53| 7·67| 10  |  3·53
    15 |   1·47  |  13 | 1·06| 1·47| 4·00| 7·58| 7·57| 15  |  3·38
    20 |   1·38  |  14 | 1·05| 1·47| 4·14| 7·70| 7·55| 20  |  3·12
    25 |   1·34  |  15 | 1·04| 1·53| 4·20| 7·76| 7·50| 25  |  2·97
       |         +-----+-----+-----+-----+-----+-----+     |
    28 |   1·24  |  16 | 1·05| 1·70| 4·35| 7·65| 7·41| 30  |  2·83
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   1·47  |  17 | 1·04| 1·87| 4·30| 7·68| 7·35|Mean.|  3·33
  -----+---------+     |     |     |     |     |     +-----+--------
       |March.   |  18 | 1·03| 2·00| 4·27| 7·74| 7·25|     |Decem.
     1 | 1·24    |  19 | 1·03| 2·15| 4·35| 7·65| 7·20|  1  |  2·86
     5 | 1·24    |  20 | 1·00| 2·18| 4·55| 7·54| 7·05|  5  |  2·75
       |         +-----+-----+-----+-----+-----+-----+     |
    10 | 1·08    |  21 | 1·00| 2·16| 4·59| 7·46| 6·90| 10  |  2·70
    15 | 0·98    |  22 | 0·94| 2·14| 4·59| 7·46| 6·80| 15  |  2·52
    20 | 0·94    |  23 | 0·86| 2·14| 4·62| 7·43| 6·70| 20  |  2·51
    25 | 0·84    |  24 | 0·87| 2·17| 4·62| 7·41| 6·62| 25  |  2·30
    30 | 0·86    |  25 | 0·88| 2·27| 4·65| 7·38| 6·51| 30  |  2·13
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.| 1·01    |  26 | 0·91| 2·50| 4·95| 7·50| 6·41|Mean.|  2·52
  -----+---------+     |     |     |     |     |     +-----+--------
       |April.   |  27 | 0·87| 2·70| 5·05| 7·44| 6·27|     |
     1 | 0·83    |  28 | 0·85| 2·82| 5·16| 7·44| 6·18|     |
     5 | 0·86    |  29 | 0·87| 2·86| 5·58| 7·74| 6·13|     |
    10 | 0·82    |  30 | 0·93| 2·88| 5·74| 7·81| 6·08|     |
       |         +-----+-----+-----+-----+-----+-----+     |
    15 | 0·63    |  31 | 0·95|  .. | 6·15| 7·87|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    20 | 0·72    |Mean.| 0·99| 1·78| 4·22| 7·27| 7·18|     |
       |         +-----+-----+-----+-----+-----+-----+     |
    25 | 0·73    |     |     |     |     |     |     |     |
    30 | 0·93    |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.| 0·74    |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
                                 1902
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|Month.   |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
    1  | 2·04    |  1  | 0·67| 0·86| 2·07| 4·32| 6·77|   1 |  6·23
    5  | 1·90    |  2  | 0·67| 0·86| 2·27| 4·55| 6·75|   5 |  6·14
   10  | 1·74    |  3  | 0·71| 0·86| 2·46| 4·78| 6·70|  10 |  5·73
   15  | 1·51    |  4  | 0·71| 0·85| 2·52| 4·90| 6·72|  15 |  5·14
   20  | 1·47    |  5  | 0·72| 0·85| 2·58| 5·06| 6·70|  20 |  4·62
       |         +-----+-----+-----+-----+-----+-----+     |
   25  | 1·40    |  6  | 0·82| 0·91| 2·64| 5·17| 6·72|  25 |  4·28
   30  | 1·30    |  7  | 0·78| 1·04| 2·62| 5·17| 6·77|  30 |  4·06
       +---------+     |     |     |     |     |     |     +-------
  Mean.| 1·59    |  8  | 0·75| 1·18| 2·64| 5·27| 6·95|Mean.| 5·11
  -----+---------+     |     |     |     |     |     +-----+-------
       |February.|  9  | 0·70| 1·33| 2·65| 5·37| 6·91|     |Novemb.
    1  | 1·28    | 10  | 0·67| 1·41| 2·72| 5·45| 6·96|   1 |  3·96
       |         +-----+-----+-----+-----+-----+-----+     |
    5  | 1·21    | 11  | 0·63| 1·44| 2·84| 5·49| 7·05|   5 |  3·65
   10  | 1·12    | 12  | 0·63| 1·44| 2·95| 5·55| 6·97|  10 |  3·55
   15  | 1·07    | 13  | 0·65| 1·48| 3·04| 5·67| 6·93|  15 |  3·30
   20  | 1·06    | 14  | 0·65| 1·52| 3·10| 5·85| 6·91|  20 |  3·11
   25  | 0·96    | 15  | 0·65| 1·57| 3·15| 5·85| 6·94|  25 |  3·07
       |         +-----+-----+-----+-----+-----+-----+     |
   28  | 0·94    | 16  | 0·66| 1·65| 3·15| 5·85| 6·89|  30 |  2·95
       +---------+     |     |     |     |     |     |     +-------
  Mean.| 1·09    | 17  | 0·67| 1·64| 3·22| 5·85| 6·84|Mean.|  3·34
  -----+---------+     |     |     |     |     |     +-----+-------
       |March.   | 18  | 0·68| 1·58| 3·21| 5·87| 6·77|     |Decemb.
    1  | 0·88    | 19  | 0·69| 1·50| 3·36| 5·82| 6·75|   1 |  2·94
    5  | 0·82    | 20  | 0·73| 1·49| 3·41| 5·89| 6·69|   5 |  2·88
       |         +-----+-----+-----+-----+-----+-----+     |
   10  | 0·84    | 21  | 0·76| 1·47| 3·48| 6·21| 6·67|  10 |  2·75
   15  | 0·83    | 22  | 0·77| 1·47| 3·54| 6·37| 6·63|  15 |  2·68
   20  | 0·76    | 23  | 0·82| 1·53| 3·54| 6·42| 6·55|  20 |  2·55
   25  | 0·76    | 24  | 0·85| 1·70| 3·59| 6·55| 6·47|  25 |  2·53
   30  | 0·86    | 25  | 0·86| 1·90| 3·72| 6·48| 6·37|  30 |  2·37
       +---------+-----+-----+-----+-----+-----+-----+     +-------
  Mean.| 0·81    | 26  | 0·86| 2·02| 3·82| 6·50| 6·35|Mean.|  2·66
  -----+---------+     |     |     |     |     |     +-----+-------
       |April.   | 27  | 0·87| 2·06| 3·94| 6·48| 6·38|     |
    1  | 0·83    | 28  | 0·87| 2·06|  .. | 6·45| 6·33|     |
    5  | 0·78    | 29  | 0·85| 2·10| 3·88| 6·63| 6·29|     |
   10  | 0·64    | 30  | 0·86| 2·00| 4·00| 6·80| 6·25|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   15  | 0·68    | 31  | 0·86|  .. | 4·21| 6·80|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
   20  | 0·64    |Mean.| 0·74| 1·46| 3·14| 5·80| 6·70|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   25  | 0·67    |     |     |     |     |     |     |     |
   30  | 0·61    |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.| 0·68    |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
                                 1903
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|Month.   |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
    1  | 2·36    |  1  | 0·83| 1·27| 2·80| 4·83| 7·73|  1  |  7·00
    5  | 2·43    |  2  | 0·84| 1·43| 2·82| 4·89| 7·73|  5  |  6·84
   10  | 2·24    |  3  | 0·83| 1·63| 2·82| 4·95| 7·72| 10  |  6·58
   15  | 2·15    |  4  | 0·82| 1·74| 2·89| 5·65| 7·70| 15  |  6·15
   20  | 2·09    |  5  | 0·79| 1·80| 2·93| 5·85| 7·72| 20  |  5·73
       |         +-----+-----+-----+-----+-----+-----+     |
   25  | 1·95    |  6  | 0·76| 1·84| 2·98| 5·98| 7·77| 25  |  5·86
   30  | 1·80    |  7  | 0·75| 1·85| 3·10| 6·18| 7·82| 30  |  5·33
       +---------+     |     |     |     |     |     |     +-------
  Mean.| 2·13    |  8  | 0·73| 1·86| 3·25| 6·27| 7·74|Mean.|  6·16
  -----+---------+     |     |     |     |     |     +-----+-------
       |February.|  9  | 0·72| 1·96| 3·40| 6·37| 7·72|     |Novemb.
    1  | 1·70    | 10  | 0·76| 2·10| 3·47| 6·43| 7·72|  1  |  5·17
       |         +-----+-----+-----+-----+-----+-----+     |
    5  | 1·59    | 11  | 0·79| 2·16| 3·43| 6·47| 7·72|  5  |  4·96
   10  | 1·51    | 12  | 0·80| 2·18| 3·46| 6·50| 7·53| 10  |  4·53
   15  | 1·42    | 13  | 0·80| 2·16| 3·56| 6·87| 7·64| 15  |  4·12
   20  | 1·38    | 14  | 0·79| 2·13| 3·74| 7·13| 7·52| 20  |  3·88
   25  | 1·23    | 15  | 0·77| 2·15| 3·82| 7·20| 7·45| 25  |  3·75
       |         +-----+-----+-----+-----+-----+-----+     |
   28  | 1·20    | 16  | 0·76| 2·21| 3·95| 7·40| 7·40| 30  |   ..
       +---------+     |     |     |     |     |     |     +-------
  Mean.| 1·44    | 17  | 0·76| 2·27| 4·00| 7·53| 7·40|Mean.|  4·28
  -----+---------+     |     |     |     |     |     +-----+-------
       |March.   | 18  | 0·76| 2·37| 4·02| 7·53| 7·37|     |Decemb.
    1  | 1·20    | 19  | 0·77| 2·50| 4·00| 7·67| 7·35|  1  |  3·52
    5  | 1·26    | 20  | 0·78| 2·60| 4·10| 7·75| 7·45|  5  |  3·38
       |         +-----+-----+-----+-----+-----+-----+     |
   10  | 1·16    | 21  | 0·80| 2·72| 4·10| 8·05| 7·45| 10  |  3·28
   15  | 1·10    | 22  | 0·80| 2·76| 4·13| 8·10| 7·45| 15  |  3·19
   20  | 1·07    | 23  | 0·81| 2·76| 4·23| 7·80| 7·47| 20  |  3·10
   25  | 1·01    | 24  | 0·82| 2·70| 4·37| 7·57| 7·47| 25  |  3·05
   30  | 0·92    | 25  | 0·83| 2·65| 4·50| 7·60| 7·43| 30  |  2·92
       +---------+-----+-----+-----+-----+-----+-----+     +-------
  Mean.| 1·10    | 26  | 0·86| 2·68| 4·67| 7·52| 7·43|Mean.|  3·22
  -----+---------+     |     |     |     |     |     +-----+-------
       |April.   | 27  | 0·91| 2·70| 4·73| 7·62| 7·40|     |
    1  | 0·92    | 28  | 0·96| 2·70| 4·83| 7·67| 7·30|     |
    5  | 0·95    | 29  | 1·03| 2·70| 4·85| 7·56| 7·14|     |
   10  | 0·90    | 30  | 1·09| 2·74| 4·80| 7·72| 7·04|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   15  | 0·85    | 31  | 1·17|  .. | 4·79| 7·74|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
   20  | 0·82    |Mean.| 0·82| 2·24| 3·82| 6·91| 7·52|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   25  | 0·80    |     |     |     |     |     |     |     |
   30  | 0·81    |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.| 0·86    |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
                                 1904
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|Month.   |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |
    1  |  2·90   |  1  | 1·11| 1·33| 1·95| 6·22| 6·75|     |
    5  |  2·86   |  2  | 1·09| 1·42| 1·98| 6·28| 6·67|     |
   10  |  2·75   |  3  | 1·07| 1·47| 2·14| 6·34| 6·67|     |
   15  |  2·68   |  4  | 1·07| 1·47| 2·32| 6·59| 6·68|     |
   20  |  2·59   |  5  | 1·07| 1·45| 2·43| 6·90| 6·69|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |  2·52   |  6  | 1·06| 1·45| 2·59| 6·93| 6·93|     |
   30  |  2·46   |  7  | 1·07| 1·45| 2·80| 6·97| 6·98|     |
       +---------+     |     |     |     |     |     |     |
  Mean.|  2·66   |  8  | 1·07| 1·46| 3·07| 6·87| 6·85|     |
  -----+---------+     |     |     |     |     |     |     |
       |February.|  9  | 1·09| 1·52| 3·40| 6·87| 6·89|     |
    1  |  2·50   | 10  | 1·11| 1·75| 3·70| 6·77| 6·83|     |
       |         +-----+-----+-----+-----+-----+-----+     |
    5  |  2·35   | 11  | 1·15| 1·88| 3·81| 6·70| 6·73|     |
   10  |  2·34   | 12  | 1·10| 1·97| 4·00| 6·68| 6·68|     |
   15  |  2·14   | 13  | 1·00| 2·00| 3·96| 6·65| 6·68|     |
   20  |  2·00   | 14  | 1·00| 2·00| 3·94| 6·64| 6·68|     |
   25  |  1·94   | 15  | 0·94| 1·97| 3·94| 6·66| 6·67|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   29  |  1·74   | 16  | 0·96| 1·97| 4·15| 6·60|     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|  2·14   | 17  | 0·96| 1·98| 4·35| 6·54|     |     |
  -----+---------+     |     |     |     |     |     |     |
       |  March. | 18  | 0·98| 2·00| 4·60| 6·52|     |     |
    1  |  1·67   | 19  | 0·98| 2·00| 4·78| 6·60|     |     |
    5  |  1·65   | 20  | 1·02| 2·00| 4·84| 6·47|     |     |
       |         +-----+-----+-----+-----+-----+     |     |
   10  |  1·52   | 21  | 1·09| 2·00| 5·03| 6·46|     |     |
   15  |  1·37   | 22  | 1·15| 1·90| 5·12| 6·50|     |     |
   20  |  1·29   | 23  | 1·17| 1·85| 5·00| 6·45|     |     |
   25  |  1·22   | 24  | 1·15| 1·88| 5·00| 6·50|     |     |
   30  |  1·17   | 25  | 1·09| 1·89| 5·08| 6·57|     |     |
       +---------+-----+-----+-----+-----+-----+     |     |
  Mean.|  1·39   | 26  | 1·08| 1·90| 5·41| 6·48|     |     |
  -----+---------+     |     |     |     |     |     |     |
       |  April. | 27  | 1·08| 1·91| 5·65| 6·48|     |     |
    1  |  1·25   | 28  | 1·10| 1·92| 5·60| 6·45|     |     |
    5  |  1·15   | 29  | 1·13| 1·93| 5·57| 6·69|     |     |
   10  |  1·17   | 30  | 1·19| 1·93| 5·78| 6·83|     |     |
       |         +-----+-----+-----+-----+-----+     |     |
   15  |  1·11   | 31  | 1·28|  .. | 6·00| 6·79|     |     |
       |         +-----+-----+-----+-----+-----+     |     |
   20  |  1·05   |Mean.| 1·08| 1·79| 4·13| 6·61|     |     |
       |         +-----+-----+-----+-----+-----+     |     |
   25  |  1·12   |     |     |     |     |     |     |     |
   30  |  1·10   |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|  1·14   |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========


TABLE LXV.--_Mean gauges of 30 years at Assuân._

                             1873-1902
  =====+====+====+====+====+====+====+====+====+====+====+====+====
  Date.|Jan.|Feb.|Mar.|Apr.|May.|Jun.|Jul.|Aug.|Sep.|Oct.|Nov.|Dec.
  -----+----+----+----+----+----+----+----+----+----+----+----+----
    1  |2·64|1·95|1·31|0·68|0·24|0·10|1·04|4·87|7·80|7·19|5·00|3·42
    2  |2·61|1·93|1·29|0·65|0·24|0·11|1·08|5·01|7·82|7·10|4·90|3·39
    3  |2·59|1·91|1·27|0·64|0·22|0·12|1·16|5·15|7·81|7·05|4·84|3·37
    4  |2·57|1·89|1·25|0·63|0·21|0·12|1·21|5·25|7·82|6·96|4·79|3·32
    5  |2·55|1·87|1·23|0·61|0·20|0·10|1·27|5·51|7·84|6·91|4·72|3·30
       |    |    |    |    |    |    |    |    |    |    |    |
    6  |2·53|1·84|1·21|0·58|0·18|0·12|1·34|5·71|7·82|6·85|4·66|3·26
    7  |2·51|1·82|1·18|0·56|0·17|0·13|1·41|5·94|7·82|6·77|4·54|3·24
    8  |2·47|1·81|1·17|0·56|0·16|0·15|1·49|6·15|7·81|6·71|4·47|3·20
    9  |2·46|1·78|1·15|0·54|0·14|0·17|1·57|6·38|7·81|6·66|4·37|3·19
   10  |2·44|1·76|1·13|0·52|0·13|0·19|1·65|6·52|7·80|6·59|4·35|3·16
       |    |    |    |    |    |    |    |    |    |    |    |
   11  |2·41|1·73|1·11|0·51|0·13|0·19|1·74|6·62|7·80|6·53|4·28|3·13
   12  |2·39|1·71|1·08|0·49|0·13|0·22|1·81|6·70|7·83|6·47|4·22|3·10
   13  |2·37|1·69|1·07|0·47|0·13|0·24|1·90|6·78|7·77|6·40|4·17|3·07
   14  |2·34|1·66|1·05|0·46|0·13|0·27|1·97|6·92|7·76|6·33|4·10|3·03
   15  |2·32|1·63|1·02|0·45|0·13|0·29|2·10|6·96|7·76|6·25|4·05|3·01
       |    |    |    |    |    |    |    |    |    |    |    |
   16  |2·30|1·61|1·00|0·44|0·12|0·32|2·23|7·04|7·74|6·17|4·00|2·99
   17  |2·28|1·59|0·98|0·42|0·12|0·34|2·36|7·11|7·71|6·07|3·96|2·95
   18  |2·25|1·56|0·96|0·41|0·12|0·37|2·52|7·17|7·68|6·02|3·91|2·94
   19  |2·22|1·54|0·93|0·40|0·11|0·39|2·65|7·27|7·69|5·98|3·86|2·91
   20  |2·21|1·52|0·92|0·39|0·11|0·41|2·79|7·31|7·67|5·90|3·82|2·88
       |    |    |    |    |    |    |    |    |    |    |    |
   21  |2·18|1·50|0·90|0·38|0·10|0·43|2·95|7·32|7·67|5·84|3·81|2·85
   22  |2·16|1·47|0·88|0·36|0·10|0·47|3·11|7·35|7·63|5·78|3·75|2·82
   23  |2·13|1·45|0·86|0·35|0·08|0·50|3·29|7·48|7·60|5·68|3·70|2·79
   24  |2·13|1·45|0·83|0·34|0·08|0·56|3·46|7·55|7·56|5·61|3·63|2·77
   25  |2·10|1·42|0·82|0·33|0·08|0·67|3·58|7·58|7·52|5·53|3·64|2·76
       |    |    |    |    |    |    |    |    |    |    |    |
   26  |2·08|1·39|0·79|0·31|0·08|0·71|3·73|7·60|7·53|5·45|3·61|2·73
   27  |2·05|1·38|0·77|0·29|0·08|0·79|3·94|7·66|7·43|5·37|3·57|2·68
   28  |2·04|1·35|0·75|0·27|0·08|0·83|4·16|7·66|7·37|5·30|3·54|2·65
   29  |2·02|    |0·73|0·26|0·08|0·98|4·36|7·69|7·31|5·22|3·49|2·62
   30  |1·99|    |0·71|0·24|0·08|0·97|4·58|7·74|7·25|5·15|3·42|2·60
   31  |1·96|    |0·69|    |0·09|    |4·73|7·78|    |5·07|    |2·58
       |    |    |    |    |    |    |    |    |    |    |    |
  =====+====+====+====+====+====+====+====+====+====+====+====+====

Zero is R. L. 85·00 metres.


TABLE LXV. (continued).--_Assuân Gauges._

                                 1874
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.|Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+---------
       |January. |     |     |     |     |     |     |     |October.
    1  |   2·06  |  1  |-0·41|-0·32| 1·50| 6·49| 8·70|   1 | 8·11
    5  |   1·95  |  2  |-0·37|-0·10| 1·57| 6·65| 8·72|   5 | 7·89
   10  |   1·75  |  3  |-0·37| 0·10| 1·61| 6·74| 8·83|  10 | 7·64
   15  |   1·57  |  4  |-0·37| 0·26| 1·68| 6·81| 8·90|  15 | 7·21
   20  |   1·41  |  5  |-0·39| 0·31| 1·72| 6·88| 8·95|  20 | 6·61
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |   1·23  |  6  |-0·44| 0·46| 1·81| 6·97| 8·97|  25 | 6·16
   30  |   1·00  |  7  |-0·48| 0·58| 1·93| 6·97| 8·95|  30 | 5·68
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   1·53  |  8  |-0·50| 0·71| 1·99| 6·97| 8·92|Mean.| 7·04
  -----+---------+     |     |     |     |     |     +-----+--------
       |February.|  9  |-0·50| 0·82| 2·08| 7·06| 8·88|     | Nov.
    1  |   0·94  | 10  |-0·53| 0·87| 2·15| 7·35| 8·83|   1 | 5·48
       |         +-----+-----+-----+-----+-----+-----+     |
    5  |   0·80  | 11  |-0·53| 0·87| 2·24| 7·75| 8·81|   5 | 5·19
   10  |   0·67  | 12  |-0·53| 0·84| 2·38| 8·16| 8·77|  10 | 4·87
   15  |   0·58  | 13  |-0·53| 0·82| 2·49| 8·36| 8·74|  15 | 4·58
   20  |   0·44  | 14  |-0·55| 0·78| 2·52| 8·45| 8·74|  20 | 4·31
   25  |   0·35  | 15  |-0·55| 0·71| 2·71| 8·47| 8·74|  25 | 4·17
       |         +-----+-----+-----+-----+-----+-----+     |
   28  |   0·31  | 16  |-0·57| 0·67| 2·83| 8·43| 8·70|  30 | 4·00
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   0·58  | 17  |-0·57| 0·67| 2·98| 8·36| 8·63|Mean.| 4·65
  -----+---------+     |     |     |     |     |     +-----+--------
       | March.  | 18  |-0·57| 0·64| 3·16| 8·43| 8·56|     | Dec.
    1  |   0·28  | 19  |-0·59| 0·64| 3·25| 8·50| 8·47|   1 | 3·95
    5  |   0·26  | 20  |-0·59| 0·64| 3·37| 8·36| 8·43|   5 | 3·73
       |         +-----+-----+-----+-----+-----+-----+     |
   10  |   0·19  | 21  |-0·61| 0·67| 3·43| 8·61| 8·41|  10 |  3·57
   15  |   0·13  | 22  |-0·64| 0·73| 3·66| 8·68| 8·45|  15 |  3·41
   20  |   0·04  | 23  |-0·64| 0·82| 4·02| 8·63| 8·45|  20 |  3·28
   25  |  -0·01  | 24  |-0·64| 0·94| 4·47| 8·65| 8·43|  25 |  3·16
   30  |  -0·08  | 25  |-0·64| 1·12| 4·87| 8·68| 8·38|  30 |  3·03
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|   0·11  | 26  |-0·66| 1·30| 5·21| 8·74| 8·34|Mean.|  3·45
  -----+---------+     |     |     |     |     |     +-----+--------
       | April.  | 27  |-0·66| 1·41| 5·46| 8·77| 8·32|     |
    1  |  -0·12  | 28  |-0·66| 1·45| 5·77| 8·74| 8·27|     |
    5  |  -0·26  | 29  |-0·66| 1·47| 6·07| 8·74| 8·20|     |
   10  |  -0·30  | 30  |-0·61| 1·47| 6·20| 8·70| 8·16|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   15  |  -0·32  | 31  |-0·50|  .. | 6·31| 8·68|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
   20  |  -0·39  |Mean.|-0·54| 0·74| 3·27| 8·00| 8·62|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |  -0·46  |     |     |     |     |     |     |     |
   30  |  -0·46  |     |     |     |     |     |     |     |
  -----+---------+     |     |     |     |     |     |     |
  Mean.|  -0·34  |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========

Zero is R. L. 85·00 metres.

                                 1877
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.|Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
    1  |  2·62   |  1  | 0·35| 0·19| 1·30| 4·72| 6·18|   1 | 6·04
    5  |  2·54   |  2  | 0·37| 0·22| 1·48| 4·74| 6·20|   5 | 5·64
   10  |  2·42   |  3  | 0·37| 0·24| 1·63| 4·74| 6·25|  10 | 5·21
   15  |  2·26   |  4  | 0·35| 0·26| 1·75| 4·74| 6·27|  15 | 4·92
   20  |  2·13   |  5  | 0·35| 0·28| 1·81| 4·88| 6·27|  20 | 4·63
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |  1·99   |  6  | 0·33| 0·31| 1·86| 4·85| 6·27|  25 | 4·53
   30  |  1·81   |  7  | 0·33| 0·31| 1·90| 5·03| 6·22|  30 | 4·09
       +---------+     |     |     |     |     |     |     +--------
  Mean.|  2·25   |  8  | 0·35| 0·33| 1·97| 5·26| 6·18|Mean.| 5·01
  -----+---------+     |     |     |     |     |     +-----+--------
       |February.|  9  | 0·40| 0·37| 2·04| 5·39| 6·11|     |Novemb.
    1  |  1·77   | 10  | 0·42| 0·46| 2·13| 5·35| 6·09|   1 | 3·88
       |         +-----+-----+-----+-----+-----+-----+     |
    5  |  1·70   | 11  | 0·42| 0·55| 2·26| 5·37| 6·13|   5 | 3·73
   10  |  1·57   | 12  | 0·40| 0·69| 2·44| 5·37| 6·16|  10 | 3·61
   15  |  1·39   | 13  | 0·37| 0·80| 2·71| 5·41| 6·13|  15 | 3·41
   20  |  1·25   | 14  | 0·33| 0·87| 3·01| 5·55| 6·07|  20 | 3·23
   25  |  1·17   | 15  | 0·28| 0·91| 3·23| 5·75| 6·02|  25 | 2·94
       |         +-----+-----+-----+-----+-----+-----+     |
   28  |  1·17   | 16  | 0·26| 0·96| 3·32| 6·07| 6·00|  30 | 2·67
       +---------+     |     |     |     |     |     |     +--------
  Mean.|  1·43   | 17  | 0·24| 1·03| 3·32| 6·18| 6·02|Mean.| 3·35
  -----+---------+     |     |     |     |     |     +-----+--------
       | March.  | 18  | 0·22| 1·07| 3·28| 6·22| 6·04|     |Decemb.
    1  |  1·14   | 19  | 0·17| 1·09| 3·21| 6·34| 6·00|   1 | 2·60
    5  |  1·09   | 20  | 0·17| 1·09| 3·23| 6·40| 5·95|   5 | 2·51
       |         +-----+-----+-----+-----+-----+-----+     +
   10  |  0·96   | 21  | 0·15| 1·09| 3·32| 6·29| 6·02|  10 | 2·40
   15  |  0·78   | 22  | 0·15| 1·07| 3·46| 6·18| 6·11|  15 | 2·22
   20  |  0·69   | 23  | 0·15| 1·07| 3·57| 6·13| 6·25|  20 | 2·13
   25  |  0·58   | 24  | 0·15| 1·07| 3·64| 6·13| 6·27|  25 | 1·95
   30  |  0·49   | 25  | 0·13| 1·07| 3·70| 6·13| 6·27|  30 | 1·97
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|  0·82   | 26  | 0·10| 1·05| 3·72| 6·11| 6·20|Mean.| 2·25
  -----+---------+     |     |     |     |     |     +-----+--------
       | April.  | 27  | 0·10| 1·05| 3·99| 6·13| 6·11|     |
    1  |  0·46   | 28  | 0·13| 1·07| 4·21| 6·18| 6·11|     |
    5  |  0·40   | 29  | 0·15| 1·09| 4·54| 6·18| 6·13|     |
   10  |  0·33   | 30  | 0·17| 1·16| 4·65| 6·18| 6·09|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   15  |  0·31   | 31  | 0·19|  .. | 4·67| 6·16|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
   20  |  0·42   |Mean.| 0·26| 0·74| 2·94| 5·68| 6·13|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |  0·51   |     |     |     |     |     |     |     |
   30  |  0·35   |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|  0·40   |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+====+=========

Zero is R. L. 85·00 metres.

                                 1878
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.|Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+---------
       |January. |     |     |     |     |     |     |     |October.
    1  |  1·97   |  1  |-0·41|-0·66| 0·67| 5·39| 7·60|   1 | 9·15
    5  |  1·88   |  2  |-0·44|-0·66| 0·71| 5·46| 7·73|   5 | 8·92
   10  |  1·75   |  3  |-0·46|-0·66| 0·78| 5·48| 7·89|  10 | 8·47
   15  |  1·61   |  4  |-0·48|-0·66| 0·87| 5·55| 8·02|  15 | 7·91
   20  |  1·48   |  5  |-0·48|-0·68| 0·91| 5·62| 8·14|  20 | 7·60
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |  1·39   |  6  |-0·46|-0·68| 0·96| 5·62| 8·23|  25 | 7·42
   30  |  1·23   |  7  |-0·46|-0·71| 1·00| 5·53| 8·32|  30 | 6·83
       +---------+     |     |     |     |     |     |     +--------
  Mean.|  1·62   |  8  |-0·48|-0·71| 1·03| 5·41| 8·38|Mean.| 8·05
  -----+---------+     |     |     |     |     |     +-----+--------
       |February.|  9  |-0·50|-0·71| 1·03| 5·68| 8·47|     |Novem.
    1  |  1·21   | 10  |-0·50|-0·68| 1·05| 6·25| 8·52|   1 | 6·72
       |         +-----+-----+-----+-----+-----+-----+     |
    5  |  1·07   | 11  |-0·50|-0·66| 1·07| 6·31| 8·56|   5 | 6·34
   10  |  0·91   | 12  |-0·50|-0·66| 1·12| 6·72| 8·70|  10 | 5·86
   15  |  0·80   | 13  |-0·48|-0·66| 1·18| 6·88| 8·81|  15 | 5·50
   20  |  0·67   | 14  |-0·48|-0·66| 1·27| 7·06| 8·86|  20 | 5·17
   25  |  0·51   | 15  |-0·50|-0·66| 1·44| 7·17| 8·90|  25 | 4·92
       |         +-----+-----+-----+-----+-----+-----+     |
   28  |  0·46   | 16  |-0·50|-0·64| 1·70| 7·17| 8·86|  30 | 4·69
       +---------+     |     |     |     |     |     |     +--------
  Mean.|  0·80   | 17  |-0·50|-0·61| 1·97| 7·10| 8·83|Mean.| 5·60
  -----+---------+     |     |     |     |     |     +-----+--------
       |March    | 18  |-0·53|-0·59| 2·17| 7·12| 8·83|     |Decem.
    1  |  0·44   | 19  |-0·55|-0·59| 2·33| 7·26| 8·81|   1 | 4·67
    5  |  0·33   | 20  |-0·57|-0·59| 2·47| 7·48| 8·86|   5 | 4·57
       |         +-----+-----+-----+-----------+-----+     |
   10  |  0·24   | 21  |-0·57|-0·61| 2·76| 7·73| 8·86|  10 | 4·38
   15  |  0·17   | 22  |-0·57|-0·61| 2·98| 7·89| 8·81|  15 | 4·20
   20  |  0·08   | 23  |-0·59|-0·59| 3·33| 7·96| 8·86|  20 | 4·09
   25  | -0·03   | 24  |-0·61|-0·50| 3·48| 8·02| 8·92|  25 | 3·93
   30  | -0·05   | 25  |-0·64|-0·32| 3·82| 8·07| 8·99|  30 | 3·77
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|  0·17   | 26  |-0·64|-0·05| 4·22| 8·09| 8·97|Mean.| 4·23
  -----+---------+     |     |     |     |     |     +-----+--------
       |April.   | 27  |-0·64| 0·19| 4·45| 7·91| 8·92|     |
    1  | -0·10   | 28  |-0·66| 0·40| 4·63| 7·69| 9·01|     |
    5  | -0·12   | 29  |-0·68| 0·58| 4·78| 7·57| 9·08|     |
   10  | -0·19   | 30  |-0·68| 0·64| 4·96| 7·53| 9·13|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   15  | -0·26   | 31  |-0·68|  .. | 5·21| 7·55|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
   20  | -0·26   |Mean.|-0·56|-0·47| 2·27| 6·85| 8·63|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   25  | -0·37   |     |     |     |     |     |     |     |
   30  | -0·41   |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.| -0·25   |     |     |     |     |     |     |     |
       |         |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========

Zero is R. L. 85·00 metres.

                                 1901
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.|Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
    1  |  1·97   |   1 |-0·37|-0·08| 0·37| 3·89| 7·42|  1  |  6·56
    5  |  1·93   |   2 |-0·39|-0·08| 0·49| 3·95| 7·38|  5  |  6·09
   10  |  1·79   |   3 |-0·41|-0·10| 0·67| 4·02| 7·44| 10  |  5·59
   15  |  1·66   |   4 |-0·44|-0·10| 0·82| 4·13| 7·62| 15  |  5·06
   20  |  1·57   |   5 |-0·44|-0·10| 0·96| 4·32| 7·76| 20  |  4·67
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |  1·48   |   6 |-0·46|-0·12| 1·05| 4·67| 7·82| 25  |  4·31
   30  |  1·25   |   7 |-0·46|-0·12| 1·09| 5·28| 7·82| 30  |  4·15
       +---------+     |     |     |     |     |     |     +--------
  Mean.|  1·66   |   8 |-0·46|-0·14| 1·15| 5·82| 7·76|Mean.|  5·20
  -----+---------+     |     |     |     |     |     +-----+--------
       |February.|   9 |-0·46|-0·19| 1·23| 6·09| 7·73|     |  Nov.
    1  |  1·21   |  10 |-0·46|-0·21| 1·39| 6·23| 7·71|  1  |  3·95
       |         +-----+-----+-----+-----+-----+-----+     |
    5  |  1·07   |  11 |-0·44|-0·21| 1·57| 6·36| 7·69|  5  |  3·75
   10  |  0·96   |  12 |-0·44|-0·23| 1·70| 6·52| 7·69| 10  |  3·55
   15  |  0·87   |  13 |-0·41|-0·26| 1·81| 6·61| 7·67| 15  |  3·32
   20  |  0·71   |  14 |-0·39|-0·26| 1·90| 6·68| 7·64| 20  |  3·07
   25  |  0·67   |  15 |-0·35|-0·26| 1·95| 6·77| 7·55| 25  |  2·89
       |         +-----+-----+-----+-----+-----+-----+     |
   28  |  0·58   |  16 |-0·30|-0·26| 2·05| 6·97| 7·48| 30  |  2·67
       +---------+     |     |     |     |     |     |     +--------
  Mean.|  0·87   |  17 |-0·26|-0·23| 2·24| 7·31| 7·55|Mean.|  3·31
  -----+---------+     |     |     |     |     |     +-----+--------
       | March.  |  18 |-0·23|-0·21| 2·56| 7·58| 7·60|     |  Dec.
    1  |  0·55   |  19 |-0·21|-0·19| 2·67| 7·69| 7·62|  1  |  2·65
    5  |  0·49   |  20 |-0·19|-0·17| 2·78| 7·80| 7·55|  5  |  2·51
       |         +-----+-----+-----+-----+-----+-----+     |
   10  |  0·40   |  21 |-0·14|-0·14| 2·83| 7·80| 7·51| 10  |   2·35
   15  |  0·27   |  22 |-0·12|-0·10| 2·89| 7·78| 7·46| 15  |   2·26
   20  |  0·17   |  23 |-0·12|-0·05| 3·01| 7·75| 7·37| 20  |   2·17
   25  |  0·08   |  24 |-0·10|-0·03| 3·07| 7·73| 7·25| 25  |   2·08
   30  | -0·03   |  25 |-0·08|-0·01| 3·26| 7·62| 7·22| 30  |   1·90
       +---------+-----+-----+-----+-----+-----+-----+     +---------
  Mean.|  0·27   |  26 |-0·08| 0·06| 3·48| 7·53| 7·10|Mean.|   2·27
  -----+---------+     |     |     |     |     |     +-----+---------
       | April.  |  27 |-0·05| 0·10| 3·61| 7·49| 6·99|     |
    1  | -0·07   |  28 |-0·03| 0·22| 3·66| 7·44| 6·63|     |
    5  | -0·10   |  29 |-0·01| 0·31| 3·68| 7·39| 6·70|     |
   10  | -0·17   |  30 |-0·03| 0·35| 3·73| 7·35| 6·61|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   15  | -0·24   |  31 |-0·08|  .. | 3·80| 7·42|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
   20  | -0·26   |Mean.|-0·27|-0·09| 2·18| 6·51| 7·44|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   25  | -0·28   |     |     |     |     |     |     |     |
   30  | -0·32   |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.| -0·20   |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========

Zero is R. L. 85·00 metres.

                                 1902
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.|Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
    1  |  1·86   |   1 |-0·39|-0·46| 0·42| 2·56| 6·16|  1  |  6·20
    5  |  1·79   |   2 |-0·39|-0·48| 0·49| 2·65| 6·13|  5  |  6·00
   10  |  1·61   |   3 |-0·39|-0·50| 0·49| 2·69| 6·09| 10  |  5·89
   15  |  1·41   |   4 |-0·37|-0·53| 0·49| 2·76| 6·09| 15  |  5·64
   20  |  1·21   |   5 |-0·39|-0·55| 0·49| 2·83| 6·20| 20  |  5·30
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |  0·98   |   6 |-0·41|-0·57| 0·46| 2·92| 6·38| 25  |  4·67
   30  |  0·85   |   7 |-0·41|-0·52| 0·46| 3·03| 6·45| 30  |  4·09
       +---------+     |     |     |     |     |     |     +--------
  Mean.|  1·38   |   8 |-0·43|-0·52| 0·49| 3·10| 6·45|Mean.|  5·40
  -----+---------+     |     |     |     |     |     +-----+--------
       |February.|   9 |-0·46|-0·50| 0·56| 3·16| 6·40|     |  Nov.
    1  |  0·78   |  10 |-0·46|-0·46| 0·65| 3·25| 6·36|  1  |  3·97
       |         +-----+-----+-----+-----+-----+-----+     |
    5  |  0·67   |  11 |-0·46|-0·37| 0·83| 3·41| 6·31|  5  |  3·77
   10  |  0·62   |  12 |-0·48|-0·35| 0·87| 3·66| 6·36| 10  |  3·37
   15  |  0·49   |  13 |-0·48|-0·30| 0·94| 4·00| 6·37| 15  |  3·10
   20  |  0·42   |  14 |-0·48|-0·30| 0·96| 4·29| 6·47| 20  |  2·85
   25  |  0·33   |  15 |-0·46|-0·26| 1·01| 4·42| 6·58| 25  |  2·60
       |         +-----+-----+-----+-----+-----+-----+     |
   28  |  0·26   |  16 |-0·43|-0·30| 1·07| 4·56| 6·65| 30  |  2·30
       +---------+     |     |     |     |     |     |     +--------
  Mean.|  0·51   |  17 |-0·41|-0·23| 1·23| 4·67| 6·72|Mean.|  3·15
  -----+---------+     |     |     |     |     |     +-----+--------
       | March.  |  18 |-0·39|-0·21| 1·39| 4·78| 6·72|     |  Dec.
    1  |  0·22   |  19 |-0·39|-0·28| 1·54| 4·87| 6·65|  1  |  2·33
    5  |  0·15   |  20 |-0·39|-0·30| 1·61| 4·94| 6·58|  5  |  2·31
       |         +-----+-----+-----+-----+-----+-----+     |
   10  |  0·10   |  21 |-0·41|-0·32| 1·66| 5·08| 6·58| 10  |  2·15
   15  |  0·01   |  22 |-0·39|-0·32| 1·70| 5·28| 6·61| 15  |  2·04
   20  | -0·08   |  23 |-0·37|-0·30| 1·77| 5·39| 6·58| 20  |  1·81
   25  | -0·17   |  24 |-0·39|-0·23| 1·87| 5·42| 6·52| 25  |  1·79
   30  | -0·21   |  25 |-0·39|-O·16| 1·97| 5·37| 6·47| 30  |  1·55
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|  0·00   |  26 |-0·39|-0·05| 2·08| 5·32| 6·43|Mean.|   2·00
  -----+---------+     |     |     |     |     |     +-----+--------
       | April.  |  27 |-0·41| 0·11| 2·20| 5·32| 6·36|     |
   1   | -0·21   |  28 |-0·43| 0·20| 2·29| 5·44| 6·31|     |
   5   | -0·23   |  29 |-0·43| 0·24| 2·38| 5·71| 6·27|     |
  10   | -0·30   |  30 |-O·46| 0·33| 2·45| 5·96| 6·23|     |
       |         +-----+-----+-----+-----+-----+-----+     |
  15   | -0·26   |  31 |-0·46|  .. | 2·54| 6·11|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
  20   | -0·23   | Mean|-0·42|-0·28| 1·27| 4·29| 6·41|     |
       |         +-----+-----+-----+-----+-----+-----+     |
  25   | -0·30   |     |     |     |     |     |     |     |
  30   | -0·39   |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.| -0·27   |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========

Zero is R. L. 85·00 metres.

                                 1903
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.|Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       | January.|     |     |     |     |     |     |     |October.
    1  |   1·52  |   1 |-0·62|-0·19| 1·07| 3·14| 7·37|  1  | 7·30
    5  |   1·66  |   2 |-0·64|-0·19| 1·16| 3·21| 7·39|  5  | 7·06
   10  |   1·34  |   3 |-0·62|-0·19| 1·27| 3·32| 7·35| 10  | 6·58
   15  |   1·36  |   4 |-0·59|+0-01| 1·39| 3·52| 7·39| 15  | 6·40
   20  |   1·32  |   5 |-0·52|-0·05| 1·48| 3·77| 7·53| 20  | 6·07
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |   1·07  |   6 |-0·52|-0·03| 1·52| 3·95| 7·58| 25  | 5·55
   30  |   1·07  |   7 |-0·50|+0·01| 1·52| 4·11| 7·56| 30  | 5·30
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   1·33  |   8 |-0·57| 0·01| 1·52| 4·13| 7·62|Mean.| 6·32
  -----+---------+     |     |     |     |     |     +-----+--------
       | February|   9 |-0·57|-0·03| 1·52| 4·11| 7·02|     |Novemb.
    1  |   0·85  |  10 |-0·57|-0·01| 1·55| 4·09| 7·62|  1  | 5·46
       |         +-----+-----+-----+-----+-----+-----+  5  | 5·15
    5  |   0·82  |  11 |-0·59| 0·01| 1·57| 4·13| 7·68|     |
   10  |   0·73  |  12 |-0·59| 0·01| 1·59| 4·34| 7·75| 10  | 4·67
   15  |   0·51  |  13 |-0·59| 0·06| 1·59| 4·90| 7·75| 15  | 4·25
   20  |   0·40  |  14 |-0·64| 0·08| 1·66| 5·44| 7·73| 20  | 4·06
   25  |   0·28  |  15 |-0·55| 0·13| 1·68| 5·73| 7·66| 25  | 3·52
       |         +-----+-----+-----+-----+-----+-----+     |
   28  |   0·06  |  16 |-0·55| 0·20| 1·72| 5·91| 7·64| 30  | 3·21
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   0·52  |  17 |-0·55| 0·20| 1·75| 6·04| 7·62|Mean.| 4·33
  -----+---------+     |     |     |     |     |     +-----+--------
       |  March. |  18 |-0·57| 0·74| 1·82| 6·13| 7·58|     |Decemb.
    1  |   0·06  |  19 |-0·57| 0·94| 1·91| 6·34| 7·55|  1  | 3·16
    5  |   0·10  |  20 |-0·55| 1·10| 2·02| 6·65| 7·48|  5  | 3·03
       |         +-----+-----+-----+-----+-----+-----+     |
   10  |   0·10  |  21 |-0·48| 1·12| 2·18| 7·01| 7·42| 10  |  2·71
   15  |  -0·03  |  22 |-0·28| 1·23| 2·33| 7·21| 7·35| 15  |  2·51
   20  |  -0·05  |  23 |-0·28| 1·34| 2·44| 7·39| 7·35| 20  |  2·33
   25  |  -0·26  |  24 |-0·21| 1·14| 2·47| 7·49| 7·28| 25  |  2·31
   30  |  -0·28  |  25 |-0·35| 1·12| 2·56| 7·66| 7·33| 30  |  2·15
       +---------+-----+-----|-----+-----+-----+-----+     +--------
  Mean.|  -0·05  |  26 |-0·35| 1·27| 2·69| 7·82| 7·35|Mean.|  2·60
  -----+---------+     |     |     |     |     |     +-----+--------
       |  April. |  27 |-0·37| 1·30| 2·85| 7·93| 7·35|     |
    1  |  -0·28  |  28 |-0·37| 0·92| 2·96| 7·84| 7·33|     |
    5  |  -0·23  |  29 |-0·34| 0·92| 3·03| 7·66| 7·35|     |
   10  |  -0·39  |  30 |-0·28| 0·98| 3·07| 7·53| 7·33|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   15  |  -0·48  |  31 |-0·14|  .. | 3·12| 7·46|  .. |     |
       |         |-----+-----+-----+-----+-----+-----+     |
   20  |  -0·39  | Mean|-0·48| 0·47| 1·97| 5·68| 7·50|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |  -0·59  |     |     |     |     |     |     |     |
   30  |  -0·62  |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|  -0·43  |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========

Zero is R. L. 85·00 metres.

                                 1904
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.|  Month. |Date.| May.|June.|July.| Au- |Sept.|Date.|Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
     1 |  2·11   |   1 |-0·08| 0·26| 0·94| 4·45| 6·34|  1  |   ..
     5 |  2·13   |   2 |-0·12| 0·28| 0·89| 4·49| 6·34|  5  |   ..
    10 |  1·95   |   3 |-0·14| 0·28| 0·87| 4·60| 6·27| 10  |   ..
    15 |  1·86   |   4 |-0·21| 0·28| 0·87| 4·87| 6·27| 15  |   ..
    20 |  1·79   |   5 |-0·21| 0·28| 0·85| 5·10| 6·47| 20  |   ..
       |         +-----+-----+-----+-----+-----+-----+     |
    25 |  1·68   |   6 |-0·19| 0·33| 0·83| 5·28| 6·61| 25  |   ..
    30 |  1·57   |   7 |-0·19| 0·60| 0·83| 5·50| 6·63| 30  |   ..
       +---------+     |     |     |     |     |     |     +--------
  Mean.|  1·87   |   8 |-0·17| 0·65| 0·83| 5·84| 6·58|Mean.|   ..
  -----+---------+     |     |     |     |     |     +-----+--------
       |February.|   9 |-0·14| 0·67| 0·80| 6·11| 6·52|     | Novem.
     1 |  1·57   |  10 |-0·14| 0·69| 0·78| 6·38| 6·47|  1  |   ..
       |         +-----+-----+-----+-----+-----+-----+     |
     5 |  1·52   |  11 |-0·05| 0·71| 0·78| 6·63| 6·52|  5  |   ..
    10 |  1·43   |  12 |+0·14| 0·85| 0·78| 6·85| 6·58| 10  |   ..
    15 |  1·36   |  13 | 0·04| 0·89| 0·78| 6·97| 6·74| 15  |   ..
    20 |  1·29   |  14 | 0·01| 0·94| 0·80| 6·92| 6·88| 20  |   ..
    25 |  1·27   |  15 |-0·05| 0·92| 0·83| 6·85| 6·83| 25  |   ..
       |         +-----+-----+-----+-----+-----+-----+     |
    28 |  1·17   |  16 |-0·05| 0·96| 0·87| 6·74|  .. | 30  |   ..
       +---------+     |     |     |     |     |     |     +--------
  Mean.|  1·37   |  17 |-0·05| 1·05| 0·94| 6·65|  .. |Mean.|   ..
  -----+---------+     |     |     |     |     |     +-----+--------
       | March.  |  18 |-0·05| 1·14| 1·03| 6·61|  .. |     | Decem.
     1 |  1·03   |  19 |-0·05| 1·18| 1·28| 6·56|  .. |  1  |   ..
     5 |  0·74   |  20 |-0·05| 1·23| 1·61| 6·54|  .. |  5  |   ..
       |         +-----+-----+-----+-----+-----+-----+     |
    10 |  0·71   | 21  | 0·15| 1·21| 2·15| 6·54|  .. | 10  |   ..
    15 |  0·69   | 22  | 0·10| 1·21| 2·62| 6.49|  .. | 15  |   ..
    20 |  0·46   | 23  | 0·13| 1·18| 2·92| 6·47|  .. | 20  |   ..
    25 |  0·42   | 24  | 0·13| 1·21| 3·08| 6·43|  .. | 25  |   ..
    30 |  0·20   | 25  | 0·15| 1·16| 3·16| 6·40|  .. | 30  |   ..
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|  0·60   | 26  | 0·13| 1·14| 3·23| 6·43|  .. |Mean.|   ..
  -----+---------+     |     |     |     |     |     +-----+--------
       | April.  | 27  | 0·10| 1·16| 3·43| 6·36|  .. |     |
     1 |  0·13   | 28  | 0·10| 1·21| 3·70| 6·34|  .. |     |
     5 | -0·10   | 29  | 0·06| 1·12| 4·02| 6·27|  .. |     |
    10 | -0·12   | 30  | 0·06| 1·07| 4·27| 6·25|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    15 |  0·04   | 31  | 0·04|  .. | 4·42| 6·29|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    20 |  0·06   |Mean.|-0·02| 0·86| 1·78| 6·14|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
    25 |  0·04   |     |     |     |     |     |     |     |
    30 | -0·03   |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|  0·00   |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========

Zero is R. L. 85·00 metres.


TABLE LXVI.--_Assuân Reservoir gauges._

R. L. OF ZERO 85·00 METRES.

  =====+=====+=====+=====+=====+=====+=====+=====+
  Year.|Date.| Jan.| Feb.| Mar.| Apr.| May | Jun.|
  -----+-----+-----+-----+-----+-----+-----+-----+
  1902 |  1  |  .. |  .. |  .. |  .. |  .. |  .. |
       |  5  |  .. |  .. |  .. |  .. |  .. |  .. |
       | 10  |  .. |  .. |  .. |  .. |  .. |  .. |
       | 15  |  .. |  .. |  .. |  .. |  .. |  .. |
  -----+-----+-----+-----+-----+-----+-----+-----+
       | 20  |  .. |  .. |  .. |  .. |  .. |  .. |
       | 25  |  .. |  .. |  .. |  .. |  .. |  .. |
       | 30  |  .. |  .. |  .. |  .. |  .. |  .. |
  -----+-----+-----+-----+-----+-----+-----+-----+
       |Mean |  .. |  .. |  .. |  .. |  .. |  .. |
  -----+-----+-----+-----+-----+-----+-----+-----+
  1903 |  1  |20·30|21·00|21·05|20·67|19·76|17·63|
       |  5  |20·38|21·13|21·09|20·55|19·63|16·85|
       | 10  |20·41|21·06|21·00|20·34|19·39|15·69|
       | 15  |20·61|21·03|20·92|20·19|19·18|14·41|
  -----+-----+-----+-----+-----+-----+-----+-----+
       | 20  |20·67|21·06|20·79|19·99|18·98|12·42|
       | 25  |20·86|21·00|20·75|19·89|18·48| 9·43|
       | 30  |20·96|21·03|20·68|19·72|17·97| 7·07|
  -----+-----+-----+-----+-----+-----+-----+-----+
       |Mean |20·60|21·04|20·90|20·19|19·05|13·47|
  -----+-----+-----+-----+-----+-----+-----+-----+
  1904 |  1  |16·29|19·18|20·44|20·91|20·94|19·66|
       |  5  |16·80|19·42|20·72|21·00|20·99|19·06|
       | 10  |17·37|19·70|21·01|21·15|21·09|17·97|
       | 15  |17·81|20·00|20·96|21·25|20·91|16·22|
  -----+-----+-----+-----+-----+-----+-----+-----+
       | 20  |18·26|20·28|21·01|21·16|20·73|13·84|
       | 25  |18·66|20·37|20·94|21·06|20·33|10·26|
       | 30  |19·13|20·41|20·90|20·96|19·83| 6·56|
  -----+-----+-----+-----+-----+-----+-----+-----+
       |Mean |17·76|19·91|20·85|21·07|20·69|14·80|
  =====+=====+=====+=====+=====+=====+=====+=====+

  =====+=====+=====+=====+=====+=====+=====+=====
  Year.|Date.| Jul.| Aug.| Sep.| Oct.| Nov.| Dec.
  -----+-----+-----+-----+-----+-----+-----+-----
  1902 |  1  |  .. |  .. |  .. |  .. |12·80|17·77
       |  5  |  .. |  .. |  .. |  .. |13·72|18·16
       | 10  |  .. |  .. |  .. |  .. |14·91|18·59
       | 15  |  .. |  .. |  .. |  .. |15·73|19·02
  -----+-----+-----+-----+-----+-----+-----+-----
       | 20  |  .. |  .. |  .. | 9·90|16·58|19·39
       | 25  |  .. |  .. |  .. |10·98|17·18|19·77
       | 30  |  .. |  .. |  .. |12·50|17·67|20·25
  -----+-----+-----+-----+-----+-----+-----+-----
       |Mean |  .. |  .. |  .. |  .. |15·51|19·00
  -----+-----+-----+-----+-----+-----+-----+-----
  1903 |  1  |  .. |  .. |  .. |  .. |  .. |10·56
       |  5  |  .. |  .. |  .. |  .. |  .. |10·53
       | 10  |  .. |  .. |  .. |  .. |10·63|12·10
       | 15  |  .. |  .. |  .. |  .. |10·53|13·33
  -----+-----+-----+-----+-----+-----+-----+-----
       | 20  |  .. |  .. |  .. |  .. | 6·90|14·49
       | 25  |  .. |  .. |  .. |  .. |10·59|15·18
       | 30  |  .. |  .. |  .. |  .. |10·57|16·14
  -----+-----+-----+-----+-----+-----+-----+-----
       |Mean |  .. |  .. |  .. |  .. |  .. |13·19
  -----+-----+-----+-----+-----+-----+-----+-----
  1904 |  1  |  .. |  .. |  .. |  .. |  .. |  ..
       |  5  |  .. |  .. |  .. |  .. |  .. |  ..
       | 10  |  .. |  .. |  .. |  .. |  .. |  ..
       | 15  |  .. |  .. |  .. |  .. |  .. |  ..
  -----+-----+-----+-----+-----+-----+-----+-----
       | 20  |  .. |  .. |  .. |  .. |  .. |  ..
       | 25  |  .. |  .. |  .. |  .. |  .. |  ..
       | 30  |  .. |  .. |  .. |  .. |  .. |  ..
  -----+-----+-----+-----+-----+-----+-----+-----
       |Mean |  .. |  .. |  .. |  .. |  .. |  ..
  =====+=====+=====+=====+=====+=====+=====+=====

Zero is R. L. 85·00 metres.


TABLE LXVII.--_Cairo gauges_. (_Roda island_).

Mean of 20 years 1873-1892.

  =====+=====+====+====+====+====+====+====+====+====+====+====+====+====
  Year.|Date.|Jan.|Feb.|Mar.|Apr.|May.|Jun.|Jul.|Aug.|Sep.|Oct.|Nov.|Dec.
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
       |  5  | 2·8| 2·2| 1·8| 1·5| 1·1| 0·9| 1·1| 4·1| 6·5| 6·9| 5·6| 3·6
       | 10  | 2·7| 2·2| 1·8| 1·4| 1·1| 0·9| 1·3| 4·9| 6·7| 6·9| 5·1| 3·4
       | 15  | 2·6| 2·1| 1·7| 1·3| 1·1| 0·9| 1·5| 5·7| 6·8| 6·8| 4·7| 3·3
       | 20  | 2·5| 2·0| 1·6| 1·3| 1·1| 0·9| 1·8| 5·9| 6·9| 6·8| 4·3| 3·2
       | 25  | 2·4| 1·9| 1·6| 1·2| 1·0| 1·0| 2·2| 6·2| 7·0| 6·7| 4·0| 3·0
       |End. | 2·3| 1·9| 1·5| 1·2| 1·0| 1·1| 2·9| 6·4| 7·1| 6·2| 3·8| 2·9
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1877 |  5  | 2·7| 2·2| 1·5| 1·3| 1·1| 0·7| 1·2| 3·6| 5·2| 5·2| 3·9| 2·9
       | 10  | 2·7| 2·1| 1·4| 1·3| 1·0| 0·7| 1·2| 4·0| 5·3| 5·0| 3·6| 2·7
       | 15  | 2·6| 1·9| 1·4| 1·2| 1·0| 0·7| 1·4| 4·7| 5·2| 4·9| 3·7| 2·6
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | 20  | 2·6| 1·8| 1·3| 1·1| 1·0| 0·8| 1·6| 4·6| 5·2| 4·6| 3·7| 2·5
       | 25  | 2·5| 1·7| 1·4| 1·1| 1·0| 1·0| 2·4| 5·3| 5·1| 4·4| 3·5| 2·4
       |End. | 2·3| 1·7| 1·4| 1·0| 1·9| 1·3| 2·8| 5·3| 5·3| 4·2| 3·1| 2·3
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |Mean.| 2·6| 1·9| 1·4| 1·2| 1·0| 0·9| 1·8| 4·6| 5·2| 4·7| 3·6| 2·6
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1878 |  5  | 2·2| 1·6| 1·0| 0·6| 0·3| 0·0|-0·2| 4·1| 6·5| 8·4| 7·5| 4·9
       | 10  | 2·1| 1·5| 0·9| 0·6| 0·2| 0·0| 0·4| 4·9| 6·8| 8·7| 7·4| 4·7
       | 15  | 2·1| 1·3| 0·9| 0·5| 0·2| 0·0| 0·8| 5·4| 7·2| 8·4| 6·9| 4·5
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | 20  | 1·9| 1·2| 1·0| 0·5| 0·2|-0·2| 1·0| 6·0| 7·6| 8·1| 6·2| 4·4
       | 25  | 1·8| 1·1| 0·8| 0·4| 0·1|-0·2| 1·4| 6·3| 7·9| 7·9| 5·5| 4·2
       |End. | 1·7| 1·1| 0·8| 0·3| 0·0|-0·2| 2·6| 6·6| 8·2| 7·7| 5·5| 4·0
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |Mean.| 1·9| 1·3| 0·9| 0·5| 0·2|-0·1| 1·0| 5·5| 7·4| 8·2| 6·5| 4·4
  -----+-----+----+----+----+----+----+----+----+----+----+----+----+----
  1879 |  5  | 3·7| 3·2| 2·7| 2·5| 2·2| 2·0| 2·1| 5·1| 7·1| 7·9| 5·9| 4·4
       | 10  | 3·6| 3·0| 2·7| 2·5| 2·2| 2·1| 2·1| 5·9| 7·0| 7·5| 5·4| 4·0
       | 15  | 3·5| 2·9| 2·6| 2·5| 2·2| 2·3| 2·6| 6·5| 7·2| 7·6| 5·0| 3·8
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       | 20  | 3·4| 2·9| 2·6| 2·4| 2·1| 2·2| 3·5| 6·9| 7·7| 7·4| 4·7| 3·7
       | 25  | 3·3| 2·8| 2·5| 2·3| 2·1| 2·2| 3·9| 7·0| 8·0| 7·3| 4·5| 3·5
       |End. | 3·2| 2·8| 2·5| 2·3| 2·0| 2·1| 4·9| 7·1| 8·1| 6·6| 4·3| 3·5
       +-----+----+----+----+----+----+----+----+----+----+----+----+----
       |Mean.| 3·5| 2·9| 2·6| 2·4| 2·1| 2·1| 3·2| 6·4| 7·5| 7·4| 5·0| 3·8
  =====+=====+====+====+====+====+====+====+====+====+====+====+====+====

Referred to zero as R. L. 12·25.


TABLE LXVII. (continued).--_Cairo gauges_ (_Roda island_).

                                 1902
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.| Month.  |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
    1  |   2·78  |  1  | 2·08| 1·73| 1·79| 3·66| 4·87|  1  |  5·68
    5  |   2·74  |  2  | 2·07| 1·75| 1·78| 3·61| 4·92|  5  |  5·60
   10  |   2·68  |  3  | 2·02| 1·75| 1·76| 3·64| 5·01| 10  |  5·51
   15  |   2·49  |  4  | 2·00| 1·78| 1·75| 3·64| 5·14| 15  |  5·57
   20  |   2·25  |  5  | 2·00| 1·80| 1·75| 3·66| 5·23| 20  |  5·66
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |   2·16  |  6  | 2·00| 1·80| 1·76| 3·66| 5·28| 25  |  5·50
   30  |   2·27  |  7  | 2·00| 1·80| 1·79| 3·68| 5·30| 30  |  5·22
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   2·45  |  8  | 1·98| 1·82| 1·88| 3·72| 5·30|Mean.|  5·53
  -----+---------+     |     |     |     |     |     +-----+--------
       |February.|  9  | 1·99| 1·83| 1·98| 3·77| 5·35|     |  Nov.
    1  |   2·27  | 10  | 1·99| 1·82| 2·07| 3·80| 5·41|  1  |  5·11
       |         +-----+-----+-----+-----+-----+-----+     |
    5  |   2·25  | 11  | 1·98| 1·80| 2·16| 3·81| 5·49|  5  |  4·96
   10  |   2·20  | 12  | 1·98| 1·80| 2·25| 3·84| 5·54| 10  |  4·65
   15  |   2·20  | 13  | 1·96| 1·81| 2·32| 3·86| 5·55| 15  |  4·44
   20  |   2·27  | 14  | 1·96| 1·80| 2·38| 3·88| 5·53| 20  |  4·38
   25  |   2·22  | 15  | 1·94| 1·80| 2·41| 3·90| 5·52| 25  |  3·95
       |         +-----+-----+-----+-----+-----+-----+     |
   28  |   2·37  | 16  | 1·94| 1·79| 2·47| 3·93| 5·53| 30  |  3·91
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   2·25  | 17  | 1·91| 1·78| 2·50| 3·95| 5·55|Mean.|  4·49
  -----+---------+     |     |     |     |     |     +-----+--------
       | March.  | 18  | 1·86| 1·76| 2·52| 3·97| 5·56|     |  Dec.
    1  |   2·37  | 19  | 1·86| 1·71| 2·56| 4·02| 5·58|  1  |  3·93
    5  |   2·32  | 20  | 1·86| 1·68| 2·58| 4·13| 5·64|  5  |  3·70
       |         +-----+-----+-----+-----+-----+-----+     |
   10  |   2·30  | 21  | 1·86| 1·66| 2·64| 4·26| 5·67| 10  |  3·29
   15  |   2·34  | 22  | 1·84| 1·64| 2·70| 4·33| 5·74| 15  |  3·05
   20  |   2·30  | 23  | 1·82| 1·66| 2·82| 4·40| 5·77| 20  |  3·05
   25  |   2·29  | 24  | 1·82| 1·69| 2·94| 4·47| 5·77| 25  |  2·95
   30  |   2·29  | 25  | 1·80| 1·71| 3·05| 4·51| 5·77| 30  |  2·78
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|   2·32  | 26  | 1·80| 1·76| 3·13| 4·58| 5·71|Mean.|  3·25
  -----+---------+     |     |     |     |     |     +-------+------
       |  April. | 27  | 1·78| 1·78| 3·23| 4·65| 5·70|     |
    1  |   2·29  | 28  | 1·78| 1·80| 3·35| 4·72| 5·69|     |
    5  |   2·27  | 29  | 1·77| 1·80| 3·50| 4·79| 5·69|     |
   10  |   2·09  | 30  | 1·75| 1·80| 3·54| 4·83| 5·68|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   15  |   2·12  | 31  | 1·74|  .. | 3·57| 4·85|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
   20  |   2·12  |Mean.| 1·92| 1·76| 2·45| 4·07| 5·44|     |
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |   2·07  |     |     |     |     |     |     |     |
   30  |   2·08  |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|   2·15  |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========

Zero is R. L. 12·25 metres.

                                 1903
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.| Month.  |Date.| May.|June.|July.| Au- |Sept.|Date.| Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
    1  |   2·78  |   1 | 2·03| 1·87| 3·25| 3·73| 6·18|  1  |  6·19
    5  |   2·69  |   2 | 2·02| 1·93| 3·48| 3·76| 6·11|  5  |  6·34
   10  |   2·64  |   3 | 2·00| 1·96| 3·55| 3·76| 6·11| 10  |  6·63
   15  |   2·67  |   4 | 2·00| 1·98| 3·54| 3·78| 6·09| 15  |  6·61
   20  |   2·51  |   5 | 1·96| 1·98| 3·59| 3·80| 6·06| 20  |  6·72
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |   2·43  |   6 | 1·93| 1·98| 3·57| 3·84| 6·04| 25  |  6·90
   30  |   2·36  |   7 | 1·89| 1·98| 3·54| 3·89| 6·02| 30  |  5·91
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   2·56  |   8 | 1·84| 1·99| 3·57| 3·89| 6·05|Mean.|  6·47
  -----+---------+     |     |     |     |     |     +-----+--------
       |February.|   9 | 1·81| 2·00| 3·54| 3·91| 6·07|     |  Nov.
    1  |    ..   |  10 | 1·79| 2·03| 3·55| 3·92| 6·14|  1  |  6·18
       |         +-----+-----+-----+-----+-----+-----+     |
    5  |   2·47  |  11 | 1·77| 2·06| 3·57| 3·94| 6·18|  5  |  6·15
   10  |   2·43  |  12 | 1·79| 2·06| 3·57| 4·02| 6·21| 10  |  5·90
   15  |   2·38  |  13 | 1·79| 2·07| 3·57| 4·06| 6·25| 15  |  5·23
   20  |   2·38  |  14 | 1·77| 2·08| 3·59| 4·19| 5·27| 20  |  4·67
   25  |   2·33  |  15 | 1·75| 2·10| 3·60| 4·24| 6·29| 25  |  4·50
       |         +-----+-----+-----+-----+-----+-----+     |
   28  |   2·30  |  16 | 1·79| 2·16| 3·62| 4·33| 6·33| 30  |  4·26
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   2·38  |  17 | 1·79| 2·20| 3·64| 4·40| 6·36|Mean.|  5·27
  -----+---------+     |     |     |     |     |     +-----+--------
       | March.  |  18 |  .. | 2·20| 3·66| 4·49| 6·39|     |  Dec.
    1  |   2·29  |  19 |  .. | 2·25| 3·64| 4·69| 6·41|  1  |  4·22
    5  |   2·24  |  20 | 1·75| 2·32| 3·68| 4·89| 6·41|  5  |  4·08
       |         +-----+-----+-----+-----+-----+-----+     |
   10  |   2·36  |  21 | 1·75| 2·36| 3·64| 5·03| 6·39| 10  |  3·99
   15  |   2·32  |  22 | 1·76| 2·39| 3·66| 5·15| 6·36| 15  |  3·50
   20  |   2·33  |  23 | 1·77|     | 3·66|     | 6·33| 20  |  3·33
   25  |   2·41  |  24 | 1·75| 2·45| 3·66| 5·40| 6·28| 25  |  3·01
   30  |   2·42  |  25 | 1·78| 2·48| 3·69| 5·55| 6·25| 30  |  2·86
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|   2·34  |  26 |  .. | 2·50| 3·68| 5·72| 6·20|Mean.|  3·57
  -----+---------+     |     |     |     |     |     +-----+--------
       | April.  |  27 | 1·80| 2·54| 3·69| 5·84| 6·15|     |
   1   |   2·40  |  28 | 1·83| 2·61| 3·69| 5·93| 6·11|     |
   5   |   2·38  |  29 | 1·85| 2·82| 3·66| 6·05| 6·10|     |
  10   |   2·25  |  30 | 1·83| 3·01| 3·70| 6·15| 6·15|     |
       |         +-----+-----+-----+-----+-----+-----+     |
  15   |   2·22  |  31 | 1·83|  .. | 3·72| 6·18|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
  20   |   2·40  |Mean.| 1·84| 2·25| 3·58| 4·61| 6·22|     |
       |         +-----+-----+-----+-----+-----+-----+     |
  25   |   2·20  |     |     |     |     |     |     |     |
  30   |   2·04  |     |     |     |     |     |     |     |
       +---------+     |     |     |     |     |     |     |
  Mean.|   2·27  |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========

Zero is R. L. 12·25 metres.

                                 1904
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========
  Date.| Month.  |Date.| May.|June.|July.| Au- |Sept.|Date.|Month.
       |         |     |     |     |     |gust.|     |     |
  -----+---------+-----+-----+-----+-----+-----+-----+-----+--------
       |January. |     |     |     |     |     |     |     |October.
    1  |   2·82  |   1 | 2·58| 2·60| 3·59| 3·88| 5·68|  1  |  ..
    5  |   2·69  |   2 | 2·58| 2·65| 3·59| 3·93| 5·66|  5  |  ..
   10  |   2·12  |   3 | 2·56| 3·05| 3·57| 4·04| 5·64| 10  |  ..
   15  |   2·54  |   4 | 2·56| 2·90| 3·56| 4·15| 5·62| 15  |  ..
   20  |   2·47  |   5 | 2·57| 2·75| 3·59| 4·26| 5·65| 20  |  ..
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |   2·41  |   6 | 2·57| 2·80| 3·59| 4·38| 5·65| 25  |  ..
   30  |   2·44  |   7 | 2·54| 2·84| 3·59| 4·47| 5·66| 30  |  ..
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   2·50  |   8 | 2·56| 2·86| 3·57| 4·56| 5·67|Mean.|  ..
  -----+---------+     |     |     |     |     |     +-----+--------
       |February.|   9 | 2·54| 2·88| 3·57| 4·65| 5·69|     |Novem.
    1  |   2·50  |  10 | 2·54| 2·92| 3·54| 4·76| 5·75|  1  |  ..
       |         +-----+-----+-----+-----+-----+-----+     |
    5  |   2·62  |  11 | 2·52| 2·97| 3·54| 4·84| 5·79|  5  |  ..
   10  |   2·74  |  12 | 2·52| 3·01| 3·54| 5·14| 5·83| 10  |  ..
   15  |   2·70  |  13 | 2·54|  -- | 3·55| 5·40| 5·84| 15  |  ..
   20  |   2·66  |  14 | 2·56| 3·08| 3·54| 5·62| 5·82| 20  |  ..
   25  |   2·83  |  15 | 2·54| 3·09| 3·57| 5·80| 5·80| 25  |  ..
       |         +-----+-----+-----+-----+-----+-----+     |
   28  |   2·83  |  16 | 2·52| 3·07| 3·54| 5·94| 5·83| 30  |  ..
       +---------+     |     |     |     |     |     |     +--------
  Mean.|   2·70  |  17 | 2·50| 3·10| 3·54| 5·95| 5·85|Mean.|  ..
  -----+---------+     |     |     |     |     |     +-----+--------
       | March.  |  18 | 2·54| 3·15| 3·54| 5·97| 5·89|     |Decem.
    1  |   2·73  |  19 | 2·54| 3·23| 3·54| 5·97| 5·93|  1  |  ..
    5  |   2·79  |  20 | 2·52| 3·35| 3·52| 5·93| 5·92|  5  |  ..
       |         +-----+-----+-----+-----+-----+-----+     |
   10  |   2·75  |  21 | 2·52| 3·50| 3·52| 5·91| 5·92| 10  |  ..
   15  |   2·70  |  22 | 2·52| 3·57| 3·54| 5·86| 5·89| 15  |  ..
   20  |   2·70  |  23 | 2·52| 3·59| 3·54| 5·82| 5·86| 20  |  ..
   25  |   2·66  |  24 | 2·51| 3·60| 3·54| 5·77| 5·80| 25  |  ..
   30  |   2·60  |  25 | 2·52| 3·55| 3·57| 5·75|  .. | 30  |  ..
       +---------+-----+-----+-----+-----+-----+-----+     +--------
  Mean.|   2·70  |  26 | 2·56| 3·55| 3·57| 5·74|  .. |Mean.|  ..
  -----+---------+     |     |     |     |     |     +-----+--------
       |  April. |  27 | 2·57| 3·57| 3·57| 5·73|  .. |     |
    1  |   2·61  |  28 | 2·58| 3·57| 3·57| 5·70|  .. |     |
    5  |   2·61  |  29 | 2·56| 3·58| 3·59| 5·69|  .. |     |
   10  |   2·56  |  30 | 2·54| 3·58| 3·73| 5·68|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
   15  |   2·60  |  31 | 2·56|  .. | 3·88| 5·68|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
   20  |   2·38  |Mean.| 2·55| 3·12| 3·14| 5·15|  .. |     |
       |         +-----+-----+-----+-----+-----+-----+     |
   25  |   2·11  |     |     |     |     |     |     |     |
   30  |   2·52  |     |     |     |     |     |     |     |
  -----+---------+     |     |     |     |     |     |     |
  Mean.|   2·48  |     |     |     |     |     |     |     |
  =====+=========+=====+=====+=====+=====+=====+=====+=====+========

Zero is R. L. 12·25 metres.


TABLE LXVIII.--_Gauges downstream of the Rosetta Weir._

  =====+=====+=====+=====+=====+=====+=====+=====+
  Year.|Date.| Jan.| Feb.| Mar.| Apr.| May.| Jun.|
  -----+-----+-----+-----+-----+-----+-----+-----+
  1902 |   1 | 3·57| 2·12| 1·00| 0·00|-0·50|-0·50|
       |   5 | 3·53| 1·95| 0·87|-0·48|-0·50|-0·50|
       |  10 | 3·40| 1·77| 0·67|-0·45|-0·50|-0·12|
       |  15 | 3·12| 1·54| 0·31|-0·48|-0·50| 0·00|
       +-----+-----+-----+-----+-----+-----+-----+
       |  20 | 2·75| 1·37| 0·60|-0·47|-0·50|-0·02|
       |  25 | 2·58| 1·15| 0·33|-0·50|-0·50| 0·00|
       |  30 | 2·24| 0·93|-0·29|-0·50|-0·50| 0·00|
       | Mean| 3·03| 1·55| 0·36|-0·41|-0·50|-0·16|
  -----+-----+-----+-----+-----+-----+-----+-----+
  1903 |   1 | 3·52| 2·56| 1·44|-0·35|-0·40|-0·46|
       |   5 | 3·48| 2·22| 1·25|-0·38|-0·42|-0·46|
       |  10 | 3·39| 1·94| 0·67|-0·38|-0·44|-0·46|
       |  15 | 3·44| 1·88| 0·50|-0·40|-0·45|-0·46|
       +-----+-----+-----+-----+-----+-----+-----+
       |  20 | 3·24| 1·79| 0·38|-0·40|-0·46|-0·46|
       |  25 | 3·03| 1·62| 0·01|-0·40|-0·46|-0·46|
       |  30 | 2·80| 1·50|-0·32|-0·40|-0·46|-0·46|
       +-----+-----+-----+-----+-----+-----+-----+
       | Mean| 3·27| 1·93| 0·56|-0·39|-0·44|-0·46|
  -----+-----+-----+-----+-----+-----+-----+-----+
  1904 |   1 | 2·98| 2·56| 2·28| 0·00|-0·33|-0·35|
       |   5 | 2·80| 3·06| 1·25|-0·20|-0·32|-0·35|
       |  10 | 2·71| 2·90| 0·50|-0·40|-0·32|-0·31|
       |  15 | 2·66| 2·75| 0·00|-0·25|-0·32|-0·32|
       +-----+-----+-----+-----+-----+-----+-----+
       |  20 | 2·57| 2·57| 0·00|-0·40|-0·32|-0·32|
       |  25 | 2·54| 2·38| 0·00|-0·32|-0·32|-0·10|
       |  30 | 2·44| 2·28| 0·00|-0·34|-0·35|-0·24|
  -----+-----+-----+-----+-----+-----+-----+-----+
       | Mean| 2·67| 2·50| 0·58|-0·27|-0·33|-0·28|
  =====+=====+=====+=====+=====+=====+=====+=====+

  =====+=====+=====+=====+=====+=====+=====+=====
  Year.|Date.| Jul.| Aug.| Sep.| Oct.| Nov.| Dec.
  -----+-----+-----+-----+-----+-----+-----+-----
  1902 |   1 | 0·00| 1·10| 4·30| 5·36| 4·54| 4·10
       |   5 | 0·00| 1·94| 4·83| 5·24| 4·27| 3·63
       |  10 | 0·05| 2·00| 5·04| 5·08| 3·85| 3·90
       |  15 | 0·03| 2·26| 5·16| 5·12| 3·50| 3·95
       +-----+-----+-----+-----+-----+-----+-----
       |  20 | 0·08| 2·87| 5·28| 5·32| 3·38| 3·99
       |  25 | 0·16| 3·77| 5·40| 5·08| 3·10| 3·84
       |  30 | 0·94| 4·22| 5·36| 4·71| 3·98| 3·58
       | Mean| 0·18| 2·60| 5·05| 5·11| 3·80| 3·89
  -----+-----+-----+-----+-----+-----+-----+-----
  1903 |   1 |-0·43| 1·92| 6·12| 6·00| 6·07| 3·20
       |   5 |-0·30| 2·75| 5·98| 6·11| 6·00| 2·90
       |  10 |-0·20| 3·45| 6·00| 6·33| 5·86| 3·18
       |  15 |-0·12| 4·05| 6·12| 6·33| 5·24| 3·11
       +-----+-----+-----+-----+-----+-----+-----
       |  20 |-0·76| 4·26| 6·22| 6·43| 4·48| 3·00
       |  25 |-0·70| 5·24| 6·07| 6·59| 3·95| 3·09
       |  30 |-1·50| 6·03| 5·95| 6·26| 3·42| 3·00
       +-----+-----+-----+-----+-----+-----+-----
       | Mean|-0·27| 3·96| 6·07| 6·29| 5·00| 3·07
  -----+-----+-----+-----+-----+-----+-----+-----
  1904 |   1 |-0·24| 1·50| 5·19|  .. |  .. |  ..
       |   5 |-0·24| 2·80| 5·11|  .. |  .. |  ..
       |  10 |-0·24| 3·96| 5·23|  .. |  .. |  ..
       |  15 |-0·24| 5·45| 5·31|  .. |  .. |  ..
       +-----+-----+-----+-----+-----+-----+-----
       |  20 |-0·24| 5·63| 5·45|  .. |  .. |  ..
       |  25 |-0·24| 5·30|  .. |  .. |  .. |  ..
       |  30 | 0·20| 5·19|  .. |  .. |  .. |  ..
  -----+-----+-----+-----+-----+-----+-----+-----
       | Mean| 0·23| 4·26|  .. |  .. |  .. |  ..
  =====+=====+=====+=====+=====+=====+=====+=====

Zero is R. L. 10·00 metres.


TABLE LXIX.--_Gauges downstream of the Damietta Weir._

  =====+=====+=====+=====+=====+=====+=====+=====+
  Year.|Date.| Jan.| Feb.| Mar.| Apr.| May.| Jun.|
  -----+-----+-----+-----+-----+-----+-----+-----+
  1902 |   1 | 0·44| 0·50| 0·75| 0·14|-0·01| 0·27|
       |   5 | 0·44| 0·55| 0·75| 0·06|-0·01| 0·27|
       |  10 | 0·41| 0·65| 0·75| 0·00|-0·01|-0·01|
       |  15 | 0·36| 0·75| 0·75| 0·00|-0·01|-0·03|
       +-----+-----+-----+-----+-----+-----+-----+
       |  20 | 0·34| 0·50| 0·27|-0·01| 0·07|-0·04|
       |  25 | 0·32| 0·75| 0·17|-0·01| 0·10|-0·04|
       |  30 | 0·50| 0·75| 0·14|-0·01| 0·21|-0·04|
       +-----+-----+-----+-----+-----+-----+-----+
       |Mean.| 0·40| 0·64| 0·51| 0·02| 0·05| 0·05|
  -----+-----+-----+-----+-----+-----+-----+-----+
  1903 |   1 | 0·42| 0·30| 0·29| 0·52|-0·12|-0·15|
       |   5 | 0·35| 0·30| 0·77| 0·14|-0·12|-0·15|
       |  10 | 0·33| 0·30| 0·95| 0·00|-0·14|-0·15|
       |  15 | 0·33| 0·30| 0·68|-0·02|-0·14|-0·15|
       +-----+-----+-----+-----+-----+-----+-----+
       |  20 | 0·33| 0·30| 0·63|-0·08|-0·15|-0·15|
       |  25 | 0·33| 0·30| 0·60|-0·10|-0·15|-0·15|
       |  30 | 0·30| 0·30| 0·67|-0·12|-0·15|-0·15|
       +-----+-----+-----+-----+-----+-----+-----+
       |Mean.| 0·34| 0·30| 0·66| 0·05|-0·14|-0·15|
  -----+-----+-----+-----+-----+-----+-----+-----+
  1904 |   1 | 3·60| 2·94| 0·72| 1·55| 0·11|-0·05|
       |   5 | 3·51| 1·88| 2·53| 1·37| 0·41|-0·08|
       |  10 | 3·46| 0·77| 3·06| 1·00| 0·46|-0·09|
       |  15 | 3·41| 0·75| 2·65| 0·45| 0·24|-0·09|
       +-----+-----+-----+-----+-----+-----+-----+
       |  20 | 3·35| 0·68| 2·38| 1·52| 0·02|-0·09|
       |  25 | 3·32| 0·66| 1·96| 1·16| 0·35| 1·06|
       |  30 | 3·24| 0·72| 1·82| 0·15|-0·02| 1·97|
       +-----+-----+-----+-----+-----+-----+-----+
       |Mean.| 3·41| 1·20| 2·16| 1·03| 0·22| 0·38|
  =====+=====+=====+=====+=====+=====+=====+=====+

  =====+=====+=====+=====+=====+=====+=====+=====
  Year.|Date.| Jul.| Aug.| Sep.| Oct.| Nov.| Dec.
  -----+-----+-----+-----+-----+-----+-----+-----
  1902 |   1 |-0·04| 1·18| 4·34| 5·26| 4·54| 2·62
       |   5 |-0·04| 1·20| 4·80| 5·14| 4·29| 2·02
       |  10 |-0·04| 2·23| 5·00| 5·02| 4·01| 1·25
       |  15 | 0·21| 2·73| 5·12| 5·06| 3·80| 0·85
       +-----+-----+-----+-----+-----+-----+-----
       |  20 | 0·35| 3·40| 5·20| 5·26| 3·75| 0·60
       |  25 | 0·38| 3·98| 5·30| 5·02| 3·52| 0·45
       |  30 | 1·20| 4·26| 5·26| 4·66| 2·77| 0·42
       +-----+-----+-----+-----+-----+-----+-----
       |Mean.| 0·29| 2·71| 5·00| 5·06| 3·81| 1·17
  -----+-----+-----+-----+-----+-----+-----+-----
  1903 |   1 |-0·13| 1·00| 6·06| 6·09| 6·15| 4·77
       |   5 | 0·67| 0·80| 6·08| 6·22| 6·09| 4·76
       |  10 | 0·33| 0·50| 6·10| 6·48| 5·95| 4·00
       |  15 | 1·20| 2·30| 6·19| 6·46| 5·46| 3·54
       +-----+-----+-----+-----+-----+-----+-----
       |  20 | 1·00| 4·32| 6·30| 6·57| 4·95| 3·44
       |  25 | 1·20| 5·29| 6·14| 6·75| 4·87| 3·68
       |  30 | 1·10| 5·98| 6·06| 6·35| 4·85| 3·62
       +-----+-----+-----+-----+-----+-----+-----
       |Mean.| 0·77| 2·88| 6·13| 6·41| 5·46| 3·97
  -----+-----+-----+-----+-----+-----+-----+-----
  1904 |   1 | 2·02| 3·08| 5·20|  .. |  .. |  ..
       |   5 | 1·75| 3·64| 5·11|  .. |  .. |  ..
       |  10 | 1·16| 4·22| 5·23|  .. |  .. |  ..
       |  15 | 0·50| 5·54| 5·31|  .. |  .. |  ..
       +-----+-----+-----+-----+-----+-----+-----
       |  20 |-0·03| 5·69| 5·47|  .. |  .. |  ..
       |  25 |-0·05| 5·32|  .. |  .. |  .. |  ..
       |  30 | 2·00| 5·20|  .. |  .. |  .. |  ..
       +-----+-----+-----+-----+-----+-----+-----
       |Mean.| 1·05| 4·67|  .. |  .. |  .. |  ..
  =====+=====+=====+=====+=====+=====+=====+=====

Zero is R. L. 10·00 metres.


Appendix M.


TABLE LXX.--_Assuân gauge. Pics referred to metres with Zero at R. L.
85·00 metres._

  =======+=======================================================+
  Kirats.|PICS AND KIRATS CONVERTED INTO METRES, REFERRED TO ZERO|
         |          AT R. L. 85·00 METRES, OR 1 PIC 14           |
         +-------+-------+-------+-------+-------+-------+-------+
         | Pic 0.| Pic 1.| Pic 2.| Pic 3.| Pic 4.| Pic 5.| Pic 6.|
         +-------+-------+-------+-------+-------+-------+-------+
         |metres.|metres.|metres.|metres.|metres.|metres.|metres.|
  -------+-------+-------+-------+-------+-------+-------+-------+
      0  |  -·84 |  -·30 |   ·24 |   ·78 |  1·32 |  1·86 |  2·40 |
      1  |  -·82 |  -·28 |   ·26 |   ·80 |  1·34 |  1·88 |  2·42 |
      2  |  -·80 |  -·25 |   ·28 |   ·82 |  1·37 |  1·91 |  2·45 |
      3  |  -·78 |  -·23 |   ·31 |   ·85 |  1·39 |  1·93 |  2·47 |
      4  |  -·75 |  -·21 |   ·33 |   ·87 |  1·41 |  1·95 | =2·50=|
      5  |  -·73 |  -·19 |   ·35 |   ·89 |  1·43 |  1·97 |  2·52 |
      6  |  -·71 |  -·17 |   ·37 |   ·92 |  1·45 | =2·00=|  2·54 |
         |       |       |       |       |       |       |       |
      7  |  -·68 |  -·14 |   ·40 |   ·94 |  1·47 |  2·02 |  2·56 |
      8  |  -·66 |  -·12 |   ·42 |   ·96 | =1·50=|  2·04 |  2·58 |
      9  |  -·64 |  -·10 |   ·44 |   ·98 |  1·52 |  2·06 |  2·60 |
     10  |  -·61 |  -·08 |   ·46 | =1·00=|  1·55 |  2·08 |  2·63 |
     11  |  -·59 |  -·06 |   ·48 |  1·02 |  1·57 |  2·11 |  2·65 |
     12  |  -·57 |  -·04 | =0·50=|  1·05 |  1·59 |  2·13 |  2·67 |
         |       |       |       |       |       |       |       |
     13  |  -·55 |  -·02 |   ·53 |  1·07 |  1·61 |  2·15 |  2·69 |
     14  |  -·52 | =0·00=|   ·55 |  1·09 |  1·63 |  2·17 |  2·71 |
     15  | -=·50=|   ·03 |   ·58 |  1·12 |  1·66 |  2·20 |  2·74 |
     16  |  -·48 |   ·06 |   ·60 |  1·14 |  1·68 |  2·22 |  2·76 |
     17  |  -·46 |   ·08 |   ·62 |  1·16 |  1·70 |  2·24 |  2·78 |
     18  |  -·44 |   ·10 |   ·65 |  1·18 |  1·73 |  2·26 |  2·81 |
         |       |       |       |       |       |       |       |
     19  |  -·41 |   ·12 |   ·67 |  1·21 |  1·75 |  2·29 |  2·83 |
     20  |  -·39 |   ·15 |   ·69 |  1·23 |  1·77 |  2·31 |  2·85 |
     21  |  -·37 |   ·17 |   ·71 |  1·25 |  1·79 |  2·33 |  2·87 |
     22  |  -·35 |   ·20 |   ·74 |  1·27 |  1·82 |  2·35 |  2·90 |
     23  |  -·32 |   ·22 |   ·76 |  1·30 |  1·34 |  2·38 |  2·92 |
  =======+=======+=======+=======+=======+=======+=======+=======+

  =======+===============================================+
  Kirats.|PICS AND KIRATS CONVERTED INTO METRES, REFERRED|
         |TO ZERO AT R. L. 85·00 METRES, OR 1 PIC 14     |
         +-------+-------+-------+-------+-------+-------+
         | Pic 7.| Pic 8.| Pic 9.|Pic 10.|Pic 11.|Pic 12.|
         +-------+-------+-------+-------+-------+-------+
         |metres.|metres.|metres.|metres.|metres.|metres.|
  -------+-------+-------+-------+-------+-------+-------+
      0  |  2·94 |  3·48 | =4·00=|  4·56 |  5·10 |  5·64 |
      1  |  2·97 | =3·50=|  4·03 |  4·58 |  5·12 |  5·66 |
      2  | =3·00=|  3·52 |  4·06 |  4·60 |  5·14 |  5·68 |
      3  |  3·02 |  3·55 |  4·08 |  4·63 |  5·17 |  5·71 |
      4  |  3·04 |  3·57 |  4·11 |  4·65 |  5·19 |  5·73 |
      5  |  3·06 |  3·59 |  4·13 |  4·67 |  5·21 |  5·75 |
      6  |  3·08 |  3·61 |  4·16 |  4·70 |  5·24 |  5·77 |
         |       |       |       |       |       |       |
      7  |  3·10 |  3·64 |  4·18 |  4·72 |  5·26 |  5·80 |
      8  |  3·12 |  3·66 |  4·20 |  4·74 |  5·28 |  5·82 |
      9  |  3·14 |  3·68 |  4·22 |  4·76 |  5·30 |  5·84 |
     10  |  3·16 |  3·70 |  4·24 |  4·78 |  5·32 |  5·86 |
     11  |  3·19 |  3·73 |  4·27 |  4·81 |  5·35 |  5·89 |
     12  |  3·21 |  3·75 |  4·29 |  4·83 |  5·37 |  5·91 |
         |       |       |       |       |       |       |
     13  |  3·23 |  3·77 |  4·31 |  4·85 |  5·39 |  5·93 |
     14  |  3·25 |  3·79 |  4·33 |  4·88 |  5·42 |  5·96 |
     15  |  3·28 |  3·82 |  4·36 |  4·90 |  5·44 |  5·98 |
     16  |  3·30 |  3·84 |  4·38 |  4·92 |  5·46 | =6·00=|
     17  |  3·32 |  3·86 |  4·40 |  4·94 |  5·48 |  6·02 |
     18  |  3·35 |  3·88 |  4·42 |  4·96 | =5·50=|  6·04 |
         |       |       |       |       |       |       |
     19  |  3·37 |  3·90 |  4·44 |  4·98 |  5·53 |  6·07 |
     20  |  3·39 |  3·92 |  4·46 | =5·00=|  5·55 |  6·09 |
     21  |  3·41 |  3·94 |  4·48 |  5·03 |  5·57 |  6·11 |
     22  |  3·43 |  3·96 | =4·50=|  5·05 |  5·60 |  6·14 |
     23  |  3·46 |  3·98 |  4·53 |  5·08 |  5·62 |  6·16 |
  =======+=======+=======+=======+=======+=======+=======+

  =======+===============================================
  Kirats.|PICS AND KIRATS CONVERTED INTO METRES, REFERRED
         |TO ZERO AT R. L. 85·00 METRES, OR 1 PIC 14
         +-------+-------+-------+-------+-------+-------
         |Pic 13.|Pic 14.|Pic 15.|Pic 16.|Pic 17.|Pic 18.
         +-------+-------+-------+-------+-------+-------
         |metres.|metres.|metres.|metres.|metres.|metres.
  -------+-------+-------+-------+-------+-------+-------
      0  |  6·18 |  6·72 |  7·26 |  7·80 |  8·34 |  8·88
      1  |  6·20 |  6·74 |  7·28 |  7·82 |  8·36 |  8·90
      2  |  6·22 |  6·76 |  7·30 |  7·84 |  8·38 |  8·92
      3  |  6·25 |  6·79 |  7·33 |  7·87 |  8·41 |  8·94
      4  |  6·27 |  6·81 |  7·35 |  7·8  |  8·43 |  8·96
      5  |  6·29 |  6·83 |  7·37 |  7·91 |  8·45 |  8·98
      6  |  6·31 |  6·85 |  7·39 |  7·93 |  8·48 | =9·00=
         |       |       |       |       |       |
      7  |  6·34 |  6·88 |  7·42 |  7·96 | =8·50=|  9·03
      8  |  6·36 |  6·90 |  7·44 |  7·98 |  8·52 |  9·06
      9  |  6·38 |  6·92 |  7·46 | =8·00=|  8·54 |  9·08
     10  |  6·41 |  6·95 |  7·48 |  8·02 |  8·57 |  9·10
     11  |  6·43 |  6·97 | =7·50=|  8·05 |  8·59 |  9·13
     12  |  6·45 | =7·00=|  7·53 |  8·07 |  8·61 |  9·15
         |       |       |       |       |       |
     13  |  6·47 |  7·02 |  7·55 |  8·09 |  8·63 |  9·17
     14  | =6·50=|  7·04 |  7·58 |  4·11 |  8·65 |  9·19
     15  |  6·52 |  7·06 |  7·60 |  8·14 |  8·68 |  9·22
     16  |  6·54 |  7·08 |  7·62 |  8·16 |  8·70 |  9·24
     17  |  6·56 |  7·10 |  7·64 |  8·18 |  8·72 |  9·26
     18  |  6·58 |  7·13 |  7·66 |  8·20 |  8·74 |  9·29
         |       |       |       |       |       |
     19  |  6·60 |  7·15 |  7·69 |  8·23 |  8·77 |  9·31
     20  |  6·63 |  7·17 |  7·71 |  8·25 |  8·79 |  9·33
     21  |  6·65 |  7·19 |  7·73 |  8·27 |  8·81 |  9·35
     22  |  6·68 |  7·21 |  7·75 |  8·29 |  8·83 |  9·37
     23  |  6·70 |  7·24 |  7·78 |  8·32 |  8·86 |  9·40
  =======+=======+=======+=======+=======+=======+=======


TABLE LXXI.--_Cairo gauge._ _Pics referred to metres with Zero at R. L.
12·25 metres._

  =======+=======================================================+
  Kirats.|PICS AND KIRATS CONVERTED INTO METRES, REFERRED TO ZERO|
         |         AT R. L. 85·00 METRES, OR 1 PIC 14            |
         +-------+-------+-------+-------+-------+-------+-------+
         | Pic 8.| Pic 9.|Pic 10.|Pic 11.|Pic 12.|Pic 13.|Pic 14.|
         +-------+-------+-------+-------+-------+-------+-------+
         |metres.|metres.|metres.|metres.|metres.|metres.|metres.|
  -------+-------+-------+-------+-------+-------+-------+-------+
      0  |   ·89 |  1·48 |  2·03 |  2·62 |  3·16 |  3·69 |  4·18 |
      1  |   ·91 | =1·50=|  2·05 |  2·65 |  3·18 |  3·71 |  4·20 |
      2  |   ·93 |  1·52 |  2·08 |  2·67 |  3·20 |  3·73 |  4·22 |
      3  |   ·95 |  1·54 |  2·10 |  2·70 |  3·22 |  3·75 |  4·24 |
      4  |   ·97 |  1·56 |  2·13 |  2·72 |  3·24 |  3·77 |  4·26 |
      5  | =1·00=|  1·59 |  2·15 |  2·74 |  3·27 |  3·79 |  4·28 |
      6  |  1·02 |  1·61 |  2·18 |  2·76 |  3·29 |  3·82 |  4·30 |
         |       |       |       |       |       |       |       |
      7  |  1·05 |  1·63 |  2·21 |  2·78 |  3·31 |  3·84 |  4·32 |
      8  |  1·07 |  1·65 |  2·24 |  2·80 |  3·34 |  3·86 |  4·34 |
      9  |  1·09 |  1·67 |  2·26 |  2·82 |  3·37 |  3·88 |  4·36 |
     10  |  1·11 |  1·69 |  2·29 |  2·84 |  3·39 |  3·90 |  4·38 |
     11  |  1·13 |  1·72 |  2·31 |  2·86 |  3·41 |  3·92 |  4·40 |
     12  |  1·15 |  1·74 |  2·33 |  2·88 |  3·43 |  3·94 |  4·42 |
         |       |       |       |       |       |       |       |
     13  |  1·17 |  1·76 |  2·35 |  2·90 |  3·46 |  3·96 |  4·44 |
     14  |  1·20 |  1·78 |  2·37 |  2·93 |  3·48 |  3·98 |  4·46 |
     15  |  1·22 |  1·81 |  2·39 |  2·95 | =3·50=| =4·00=|  4·48 |
     16  |  1·25 |  1·83 |  2·42 |  2·97 |  3·52 |  4·02 | =4·50=|
     17  |  1·28 |  1·86 |  2·45 | =3·00=|  3·54 |  4·04 |  4·52 |
     18  |  1·31 |  1·88 |  2·48 |  3·02 |  3·56 |  4·06 |  4·54 |
         |       |       |       |       |       |       |       |
     19  |  1·34 |  1·91 | =2·50=|  3·04 |  3·58 |  4·08 |  4·56 |
     20  |  1·37 |  1·94 |  2·52 |  3·06 |  3·60 |  4·10 |  4·58 |
     21  |  1·40 |  1·96 |  2·55 |  3·09 |  3·62 |  4·12 |  4·60 |
     22  |  1·42 |  1·98 |  2·57 |  3·11 |  3·64 |  4·14 |  4·62 |
     23  |  1·45 | =2·00=|  2·60 |  3·13 |  3·66 |  4·16 |  4·64 |
  =======+=======+=======+=======+=======+=======+=======+=======+

  =======+===============================================+
  Kirats.|PICS AND KIRATS CONVERTED INTO METRES, REFERRED|
         |   TO ZERO AT R. L. 85·00 METRES, OR 1 PIC 14  |
         +-------+-------+-------+-------+-------+-------+
         |Pic 15.|Pic 16.|Pic 17.|Pic 18.|Pic 19.|Pic 20.|
         +-------+-------+-------+-------+-------+-------+
         |metres.|metres.|metres.|metres.|metres.|metres.|
  -------+-------+-------+-------+-------+-------+-------+
      0  |  4·66 |  5·15 |  5·39 |  5·64 |  5·91 |  6·18 |
      1  |  4·68 |  5·16 |  5·40 |  5·65 |  5·92 |  6·19 |
      2  |  4·70 |  5·17 |  5·41 |  5·66 |  5·93 |  6·20 |
      3  |  4·72 |  5·18 |  5·42 |  5·67 |  5·94 |  6·21 |
      4  |  4·74 |  5·19 |  5·43 |  5·68 |  5·96 |  6·23 |
      5  |  4·76 |  5·20 |  5·44 |  5·69 |  5·97 |  6·24 |
      6  |  4·78 |  5·21 |  5·45 |  5·70 |  5·98 |  6·25 |
         |       |       |       |       |       |       |
      7  |  4·80 |  5·22 |  5·46 |  5·71 |  5·99 |  6·26 |
      8  |  4·82 |  5·23 |  5·47 |  5·72 | =6·00=|  6·27 |
      9  |  4·84 |  5·24 |  5·48 |  5·74 |  6·01 |  6·28 |
     10  |  4·86 |  5·25 |  5·49 |  5·75 |  6·02 |  6·29 |
     11  |  4·88 |  5·26 | =5·50=|  5·76 |  6·03 |  6·31 |
     12  |  4·90 |  5·27 |  5·51 |  5·77 |  6·04 |  6·32 |
         |       |       |       |       |       |       |
     13  |  4·92 |  5·28 |  5·52 |  5·78 |  6·05 |  6·33 |
     14  |  4·94 |  5·29 |  5·53 |  5·79 |  6·07 |  6·34 |
     15  |  4·96 |  5·30 |  5·54 |  5·80 |  6·08 |  6·35 |
     16  |  4·98 |  5·31 |  5·55 |  5·81 |  6·09 |  6·36 |
     17  | =5·00=|  5·32 |  5·57 |  5·83 |  6·10 |  6·37 |
     18  |  5·02 |  5·33 |  5·58 |  5·84 |  6·12 |  6·39 |
         |       |       |       |       |       |       |
     19  |  5·04 |  5·34 |  5·59 |  5·85 |  6·13 |  6·40 |
     20  |  5·06 |  5·35 |  5·60 |  5·87 |  6·14 |  6·41 |
     21  |  5·09 |  5·36 |  5·61 |  5·88 |  6·15 |  6·42 |
     22  |  5·11 |  5·37 |  5·62 |  5·89 |  6·16 |  6·43 |
     23  |  5·13 |  5·38 |  5·63 |  5·90 |  6·17 |  6·44 |
  =======+=======+=======+=======+=======+=======+=======+

  =======+===============================================
  Kirats.|PICS AND KIRATS CONVERTED INTO METRES, REFERRED
         |   TO ZERO AT R. L. 85·00 METRES, OR 1 PIC 14
         +-------+-------+-------+-------+-------+-------
         |Pic 21.|Pic 22.|Pic 23.|Pic 24.|Pic 25.|Pic 26.
         +-------+-------+-------+-------+-------+-------
         |metres.|metres.|metres.|metres.|metres.|metres.
  -------+-------+-------+-------+-------+-------+-------
      0  |  6·46 |  6·74 |  7·26 |  7·83 |  8·35 |  8·88
      1  |  6·47 |  6·76 |  7·28 |  7·85 |  8·37 |  8·91
      2  |  6·48 |  6·78 |  7·31 |  7·87 |  8·39 |  8·93
      3  |  6·49 |  6·80 |  7·35 |  7·89 |  8·41 |  8·95
      4  | =6·50=|  6·83 |  7·37 |  7·91 |  8·43 |  8·97
      5  |  6·51 |  6·85 |  7·39 |  7·93 |  8·46 | =9·00=
      6  |  6·52 |  6·87 |  7·41 |  7·96 |  8·48 |  9·02
         |       |       |       |       |       |
      7  |  6·53 |  6·89 |  7·43 |  7·98 | =8·50=|  9·04
      8  |  6·54 |  6·91 |  7·46 | =8·00=|  8·52 |  9·06
      9  |  6·56 |  6·93 |  7·48 |  8·02 |  8·54 |  9·09
     10  |  6·57 |  6·96 | =7·50=|  8·04 |  8·56 |  9·11
     11  |  6·58 |  6·98 |  7·52 |  8·06 |  8·59 |  9·13
     12  |  6·59 | =7·00=|  7·54 |  8·09 |  8·61 |  9·15
         |       |       |       |       |       |
     13  |  6·61 |  7·02 |  7·56 |  8·11 |  8·63 |  9·18
     14  |  6·62 |  7·04 |  7·59 |  8·13 |  8·65 |  9·20
     15  |  6·63 |  7·06 |  7·61 |  8·15 |  8·68 |  9·22
     16  |  6·64 |  7·09 |  7·63 |  8·17 |  8·70 |  9·24
     17  |  6·65 |  7·11 |  7·66 |  8·20 |  8·72 |  9·26
     18  |  6·66 |  7·13 |  7·68 |  8·22 |  8·74 |  9·29
         |       |       |       |       |       |
     19  |  6·68 |  7·16 |  7·71 |  8·24 |  8·76 |  9·31
     20  |  6·69 |  7·18 |  7·73 |  8·26 |  8·79 |  9·33
     21  |  6·70 |  7·20 |  7·75 |  8·29 |  8·81 |  9·35
     22  |  6·71 |  7·22 |  7·78 |  8·31 |  8·83 |  9·37
     23  |  6·73 |  7·24 |  7·80 |  8·33 |  8·85 |  9·40
  =======+=======+=======+=======+=======+=======+=======


Appendix N.


TABLE LXXII.--_Table for Converting Cubic Metres per Day into Cubic
Metres per Second._

  ============+============
  Cubic metres|Cubic metres
    per day.  | per second.
  ------------+------------
      10,000  |   0·1157
      20,000  |   0·2315
      30,000  |   0·3472
      40,000  |   0·4630
      50,000  |   0·5787
      60,000  |   0·6944
      70,000  |   0·8102
      80,000  |   0·9259
      90,000  |   1·0417
    =100,000= |  =1·1574=
     150,000  |   1·7361
     200,000  |   2·3148
     250,000  |   2·8935
     300,000  |   3·4722
     350,000  |   4·0509
     400,000  |   4·6296
     450,000  |   5·2083
    =500,000= |  =5·7870=
     550,000  |   6·3657
     600,000  |   6·9444
     650,000  |   7·5231
     700,000  |   8·1018
     750,000  |   8·6805
     800,000  |   9·2593
     850,000  |   9·8380
     900,000  |  10·4167
     950,000  |  10·9954
  =1,000,000= | =11·5741=
   1,250,000  |  14·4676
   1,500,000  |  17·3611
   1,750,000  |  20·2546
   2,000,000  |  23·1481
   2,250,000  |  26·0417
   2,500,000  |  28·9352
   2,750,000  |  31·8287
   3,000,000  |  34·7222
   3,250,000  |  37·6157
   3,500,000  |  40·5092
   3,750,000  |  43·4028
   4,000,000  |  46·2963
   4,250,000  |  49·1898
   4,500,000  |  52·0833
   4,750,000  |  54·9768
  =5,000,000= | =57·8704=
   5,250,000  |  60·7639
   5,500,000  |  63·6574
   5,750,100  |  66·5509
   6,000,000  |  69·4444
   6,250,000  |  72·3380
   6,500,000  |  75·2315
   6,750,000  |  78·1250
   7,000,000  |  81·0185
   7,250,000  |  83·9120
   7,500,000  |  86·8055
   7,750,000  |  89·6991
   8,000,000  |  92·5926
   8,250,000  |  95·4861
   8,500,000  |  98·3796
   8,750,000  | 101·2731
   9,000,000  | 104·1667
   9,250,000  | 107·0602
   9,500,000  | 109·9537
   9,750,000  | 112·8472
  10,000,000  | 115·7407

_Rough Working Approximations._

  ============+============
  Cubic metres|Cubic metres
    per day.  | per second.
  ------------+------------
      125,000 |     1·5
      250,000 |     3
      500,000 |     6
      750,000 |     9
    1,000,000 |    12
    2,000,000 |    24
    3,000,000 |    36
    4,000,000 |    48
    5,000,000 |    60
    6,000,000 |    72
    7,000,000 |    84
    8,000,000 |    96
    9,000,000 |   108
   10,000,000 |   120
  ============+============


TABLE LXXIII.--_Table for converting Cubic Metres per Second into Cubic
Metres per Day._

  =======+============
   Cubic |
  metres |Cubic metres
    per  |  per day.
  second.|
  -------+------------
      1  |    86,400
      2  |   172,800
      3  |   259,200
      4  |   345,600
      5  |   432,000
      6  |   518,400
      7  |   604,800
      8  |   691,200
      9  |   777,600
     10  |   864,000
     11  |   950,400
     12  | 1,036,800
     13  | 1,123,200
     14  | 1,209,600
     15  | 1,296,000
     16  | 1,382,400
     17  | 1,468,800
     18  | 1,555,200
     19  | 1,641,600
     20  | 1,728,000
     21  | 1,814,400
     22  | 1,900,800
     23  | 1,987,200
     24  | 2,073,500
     25  | 2,160,000
     26  | 2,246,400
     27  | 2,332,800
     28  | 2,419,200
     29  | 2,505,600
     30  | 2,592,000
     31  | 2,678,400
     32  | 2,764,800
     33  | 2,851,200
     34  | 2,937,600
     35  | 3,024,000
     36  | 3,110,400
     37  | 3,196,800
     38  | 3,283,200
     39  | 3,369,600
     40  | 3,456,000
     41  | 3,542,400
     42  | 3,628,800
     43  | 3,715,200
     44  | 3,801,600
     45  | 3,888,000
     46  | 3,974,400
     47  | 4,060,800
     48  | 4,147,200
     49  | 4,233,600
     50  | 4,320,000
     51  | 4,406,400
     52  | 4,492,800
     53  | 4,579,200
     54  | 4,665,600
     55  | 4,752,000
     56  | 4,838,400
     57  | 4,924,800
     58  | 5,011,200
     59  | 5,097,600
     60  | 5,184,000
     61  | 5,270,400
     62  | 5,356,800
     63  | 5,443,200
     64  | 5,529,600
     65  | 5,616,000
     66  | 5,702,400
     67  | 5,788,800
     68  | 5,875,200
     69  | 5,961,600
     70  | 6,048,000
     71  | 6,134,400
     72  | 6,220,800
     73  | 6,307,200
     74  | 6,393,600
     75  | 6,480,000
     76  | 6,566,400
     77  | 6,652,800
     78  | 6,739,200
     79  | 6,825,600
     80  | 6,912,000
     81  | 6,998,400
     82  | 7,084,800
     83  | 7,171,200
     84  | 7,257,600
     85  | 7,344,000
     86  | 7,430,400
     87  | 7,516,800
     88  | 7,603,200
     89  | 7,689,600
     90  | 7,776,000
     91  | 7,862,400
     92  | 7,948,800
     93  | 8,035,200
     94  | 8,121,600
     95  | 8,208,000
     96  | 8,294,400
     97  | 8,380,800
     98  | 8,467,200
     99  | 8,553,600
    100  | 8,640,000
  =======+============


Appendix P.


TABLE LXXIV.--_Bombay rainfall compared with the Assuân gauges._

  =====+=======================================+========================
  Year.|             BOMBAY RAINFALL           |      ASSUÂN GAUGE
       |             IN MILLIMETRES            |        IN METRES
       +-----+-----+-----+-----+-------+-------+-----+-----+------------
       |June.|July.| Au- |Sept.| Total | Varia-| Au- |Sept.| Variation
       |     |     |gust.|     |   4   |  tion |gust.|     |from normal.
       |     |     |     |     |Months.| from  |     |     +------------
       |     |     |     |     |       |normal.|     |     | Aug.|Sept.
  -----+-----+-----+-----+-----+-------+-------+-----+-----+-----+------
   1874|  474| 1046|  282|  279|  2081 |  +267 | 7·96| 8·59|+1·20| +0·91
  -----+-----+-----+-----+-----+-------+-------+-----+-----+-----+------
   1875|  618|  389|  310|  806|  2123 |  +309 | 7·32| 8·06|+0·56| +0·38
   1876|  328|  602|  220|  119|  1269 |  -545 | 7·19| 8·38|+0·43| +0·70
  -----+-----+-----+-----+-----+-------+-------+-----+-----+-----+------
   1877|  904|  281|  216|  226|  1627 |  -187 | 5·67| 6·11|-1·09| -1·57
  -----+-----+-----+-----+-----+-------+-------+-----+-----+-----+------
   1878|  505| 1227|  518|  417|  2667 |  +853 | 6·84| 8·62|+0·08| +0·94
  -----+-----+-----+-----+-----+-------+-------+-----+-----+-----+------
   1879|  420|  285|  567|  142|  1414 |  -400 | 7·39| 8·13|+0·63| +0·45
   1880|  544|  465|  104|  579|  1692 |  -122 | 6·96| 7·43|+0·20| -0·25
   1881|  387|  747|  483|  116|  1733 |   -81 | 5·96| 8·07|-0·80| +0·39
   1882|  699|  683|   85|  255|  1722 |   -92 | 6·00| 7·33|-0·76| -0·35
   1883|  346| 1011|  318|  312|  1987 |  +173 | 7·20| 7·91|+0·44| +0·23
   1884|  335|  655|  386|  432|  1808 |    -6 | 6·06| 7·04|-0·70| -0·64
   1885|  130|  554|  645|  305|  1634 |  -180 | 7·39| 7·61|+0·63| -0·07
   1886| 1103|  907|  272|  166|  2448 |  +634 | 6·38| 7·65|-0·38| -0·03
  -----+-----+-----+-----+-----+-------+-------+-----+-----+-----+------
   1887|  610|  785|  445|  463|  2303 |  +489 | 7·95| 8·62|+1·19| +0·94
  -----+-----+-----+-----+-----+-------+-------+-----+-----+-----+------
   1888|  401|  573|  289|  124|  1387 |  -427 | 5·99| 6·61|-0·77| -1·07
  -----+-----+-----+-----+-----+-------+-------+-----+-----+-----+------
   1889|  505|  775|  260|   63|  1603 |  -211 | 6·88| 7·91|+0·12| +0·23
   1890|  607|  554|  275|  168|  1604 |  -210 | 7·47| 8·14|+0·71| +0·46
   1891|  348|  830|  170|  575|  1923 |  +109 | 6·79| 7·83|+0·03| +0·15
  -----+-----+-----+-----+-----+-------+-------+-----+-----+-----+------
   1892|  338|  600|  838|  569|  2345 |  +531 | 7·14| 8·67|+0·38| +0·99
  -----+-----+-----+-----+-----+-------+-------+-----+-----+-----+------
   1893|  544|  399|  343|  197|  1483 |  -331 | 6·97| 7·43|+0·21| -0·25
   1894|  426|  662|  218|  305|  1611 |  -203 | 7·27| 8·37|+0·51| +0·69
   1895|  452|  455|  402|  307|  1616 |  -198 | 8·07| 8·10|+1·31| +0·42
   1896|  703|  923|  536|   41|  2203 |  +389 | 6·73| 8·21|-0·03| +0·53
   1897|  351|  780|  351|  520|  2002 |  +188 | 6·23| 7·53|-0·53| -0·15
   1898|  648|  564|  134|  513|  1859 |   +45 | 7·07| 8·11|+0·31| +0·43
  -----+-----+-----+-----+-----+-------+-------+-----+-----+-----+------
   1899|  527|  121|  133|   88|   869 |  -945 | 4·28| 6·16|-2·48| -1·52
  -----+-----+-----+-----+-----+-------+-------+-----+-----+-----+------
   1900|  442|  508|  603|  203|  1756 |   -58 | 6·90| 7·13|+0·14| -0·55
   1901|  627|  844|  364|   47|  1882 |   +68 | 6·48| 7·45|-0·28| -0·23
   1902|  248|  369|  468|  701|  1786 |   -28 | 4·25| 6·40|-2·51| -1·28
   1903|  472|  615|  476|  229|  1792 |   -22 | 5·68| 7·30|-1·08| -0·38
   1904|  .. |  .. |   ..|   ..|   ..  |   ..  |  .. |  .. |  .. |   ..
  =====+=====+=====+=====+=====+=======+=======+=====+=====+=====+======


Appendix Q.


TABLE LXXV.--_Station Addis Ababa._ (_Meteorological data_).

                                   1902
  =========+============+===============+===+=================+=========
    Month. | BAROMETER  |  THERMOMETER  |Hu-|       WIND      |RAINFALL
           |            |               |mi-|                 |IN MILLI-
           |            |               |di-|                 | METRES
           +-----+------+----+----+-----+ty.+------+----+-----+---------
           |Mean.|Varia-|Mean|Mean|Mean.|   |Direc-| Ve-|Fall.| Varia-
           |     | tion |max.|min.|     |   | tion.|loc-|     |  tion
           |     | from |    |    |     |   |      |ity.|     |  from
           |     | nor- |    |    |     |   |      |    |     |  nor-
           |     | mal. |    |    |     |   |      |    |     |  mal.
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |  .. |  ..  |24·3| 6·6| 15·4| ..|  S   | .. |   0 |   ..
  February |  .. |  ..  |22·0| 9·3| 15·6| ..|S 22 E| .. |  65 |   ..
  March    |  .. |  ..  |24·4|10·2| 17·3| ..|S 24 E| .. |  37 |   ..
  April    |  .. |  ..  |22·3|11·1| 16·7| ..|S 45 E| .. | 111 |   ..
  May      |  .. |  ..  |22·7|10·3| 16·5| ..|S 45 E| .. |  61 |   ..
  June     |  .. |  ..  |25·2| 9·9| 17·5| ..|S 45 E| .. | 142 |   ..
  July     |  .. |  ..  |25·0|10·2| 17·6| ..|S 45 E| .. | 205 |   ..
  August   |  .. |  ..  |24·8|10·0| 17·4| ..|S 45 E| .. | 167 |   ..
  September|  .. |  ..  |24·8| 9·8| 17·3| ..|S 45 E| .. | 129 |   ..
  October  |  .. |  ..  |25·9| 6·9| 16·4| ..|S 88 E| .. |  16 |   ..
  November |  .. |  ..  |26·4| 5·5| 15·9| ..|S 86 E| .. |   9 |   ..
  December |  .. |  ..  |25·6| 4·5| 15·0| ..|  E   | .. |  39 |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |  .. |  ..  |24·4| 8·7| 16·5| ..|S 47 E| .. | 981 |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1903
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  | ..  |  ..  |26·0| 8·7| 17·4| ..|S 51 E| .. |  32 |   ..
  February | ..  |  ..  |28·2| 8·3| 18·2| ..|S 42 E| .. |  25 |   ..
  March    | ..  |  ..  |26·7|10·5| 18·6| ..|S 45 E| .. |  94 |   ..
  April    | ..  |  ..  |27·8|10·0| 18·9| ..|S 45 E| .. |  88 |   ..
  May      | ..  |  ..  |25·7|12·2| 18·9| ..|S 45 E| .. | 117 |   ..
  June     | ..  |  ..  |24·4|10·0| 17·2| ..|S 45 E| .. | 191 |   ..
  July     | ..  |  ..  |22·4|10·0| 16·2| ..|S 45 E| .. | 276 |   ..
  August   | ..  |  ..  |21·6|10·5| 16·0| ..|S 29 E| .. | 248 |   ..
  September| ..  |  ..  |22·5| 9·7| 16·1| ..|  S   | .. | 222 |   ..
  October  | ..  |  ..  |24·5| 7·3| 15·9| ..|S 80 E| .. |  28 |   ..
  November | ..  |  ..  |24·4| 5·0| 14·7| ..|  E   | .. |   0 |   ..
  December | ..  |  ..  |23·6| 6·5| 15·0| ..|N 88 E| .. |  18 |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     | ..  |  ..  |24·8| 9·1| 17·4| ..|S 53 E| .. |1339 |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1904
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  | ..  |  ..  |25·4| 4·6|  .. | ..|      | .. |   0 |   ..
  February | ..  |  ..  |25·9| 8·4|  .. | ..|  E   | .. |  20 |   ..
  March    | ..  |  ..  |26·2| 9·2|  .. | ..|S 59 E| .. | 126 |   ..
  April    | ..  |  ..  |26·6| 9·9|  .. | ..|S 50 E| .. |  31 |   ..
  May      | ..  |  ..  |27·4|10·1|  .. | ..|N 80 E| .. |  41 |   ..
  June     | ..  |  ..  | .. | .. |  .. | ..|N 84 E| .. |  .. |   ..
  July     | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  August   | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  September| ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  October  | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  November | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  December | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  =========+=====+======+====+====+=====+===+======+====+=====+=========


TABLE LXXVI.--_Station Wad Medani (Meteorological data)._

                                   1902
  =========+============+===============+===+=================+=========
    Month. | BAROMETER  |  THERMOMETER  |Hu-|       WIND      |RAINFALL
           |            |               |mi-|                 |IN MILLI-
           |            |               |di-|                 | METRES
           +-----+------+----+----+-----+ty.+------+----+-----+---------
           |Mean.|Varia-|Mean|Mean|Mean.|   |Direc-| Ve-|Fall.| Varia-
           |     | tion |max.|min.|     |   | tion.|loc-|     |  tion
           |     | from |    |    |     |   |      |ity.|     |  from
           |     | nor- |    |    |     |   |      |    |     |  nor-
           |     | mal. |    |    |     |   |      |    |     |  mal.
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  February | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  March    |756·2|  ..  |40·2|20·9| 30·6| 18|N 10 W| .. |   0 |   ..
  April    |756·6|  ..  |41·9|28·5| 35·2| 13|  N   | .. |   0 |   ..
  May      |757·2|  ..  |44·1|26·2| 35·2| 30|S 72 W| .. |   6 |   ..
  June     |757·5|  ..  |43·1|24·4| 33·8| 41|S 36 W| .. |  53 |   ..
  July     |758·9|  ..  |38·7|23·8| 31·2| 59|S 34 W| .. | 135 |   ..
  August   |758·1|  ..  |39·7|21·2| 30·4| 64|S  5 W| .. |  78 |   ..
  September|758·4|  ..  |40·4|23·4| 31·9| 60|S  9 E| .. |  76 |   ..
  October  |758·2|  ..  |43·2|26·0| 34·6| 38|N 53 E| .. |   2 |   ..
  November |758·3|  ..  |40·8|22·9| 31·8| 27|N  5 W| .. |   0 |   ..
  December |759·9|  ..  |36·7|19·1| 27·9| 33|N 34 W| .. |   0 |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. | 350 |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1903
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |760·3|  ..  |33·4|16·8| 25·1| 30|N 33 W| .. |   0 |   ..
  February |760·8|  ..  |33·6|13·5| 23·6| 28|N  6 W| .. |   0 |   ..
  March    |758·4|  ..  |39·1|16·8| 28·0| 13|N  8 W| .. |   0 |   ..
  April    |755·2|  ..  |45·3|23·4| 34·4| 17|N 24 E| .. |   0 |   ..
  May      |756·6|  ..  |44·9|25·4| 35·2| 40|S  6 W| .. |   1 |   ..
  June     |757·3|  ..  |43·2|24·6| 33·9| 46|S  4 W| .. |  44 |   ..
  July     |757·8|  ..  |40·5|23·6| 32·0| 52|S  9 W| .. | 124 |   ..
  August   |757·6|  ..  |38·8|26·4| 30·6| 67|S 13 W| .. |  92 |   ..
  September|758·2|  ..  |39·3|25·9| 32·6| 66|S 21 W| .. |  52 |   ..
  October  |757·4|  ..  |41·4|21·8| 31·6| 50|S 63 E| .. |   0 |   ..
  November |758·0|  ..  |40·4|20·8| 30·6| 39|N 10 E| .. |   0 |   ..
  December |758·2|  ..  |38·5|16·5| 27·5| 48|N 21 E| .. |   0 |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |758·0|  ..  |39·4|21·3| 30·4| 41|N  4 E| .. | 313 |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1904
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |758·2|  ..  |37·4|17·9| 27·6| 73|N 18 E| .. |   0 |    0
  February |758·2|  ..  |36·3|15·8| 26·1| 40|N  1 W| .. |   0 |    0
  March    |756·3| -1·0 |40·4|17·7| 24·6| 22|N 10 E| .. |   0 |    0
  April    |756·8| +0·9 |41·9|20·6| 28·4| 12|N  3 W| .. |   0 |    0
  May      |756·6| -0·3 |42·5|24·3| 31·7| 27|  S   | .. |  40 |  +36
  June     |757·9| +0·5 |42·1|12·3| 27·2| 41|  S   | .. |   0 |  -49
  July     |757·7| -0·4 |39·5|14·3| 26·9| 43|  S   | .. |  70 |  -40
  August   |758·2| +0·2 |40·9|22·4| 31·6| 61|  S   | .. |  67 |  -12
  September| ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  October  | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  November | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  December | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  =========+=====+======+====+====+=====+===+======+====+=====+=========


TABLE LXXVII.--_Station Khartoum (Meteorological data)._

                                   1902
  =========+============+===============+===+=================+=========
    Month. | BAROMETER  |  THERMOMETER  |Hu-|       WIND      |RAINFALL
           |            |               |mi-|                 |IN MILLI-
           |            |               |di-|                 | METRES
           +-----+------+----+----+-----+ty.+------+----+-----+---------
           |Mean.|Varia-|Mean|Mean|Mean.|   |Direc-| Ve-|Fall.| Varia-
           |     | tion |max.|min.|     |   | tion.|loc-|     |  tion
           |     | from |    |    |     |   |      |ity.|     |  from
           |     | nor- |    |    |     |   |      |    |     |  nor-
           |     | mal. |    |    |     |   |      |    |     |  mal.
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |759·4|    0 |28·7|14·2| 20·0| 26|N  4 E| 28 |   0 |   ..
  February |758·3| -0·2 |34·7|19·1| 26·1| 18|N 17 E| 21 |   0 |   ..
  March    |756·1| -1·4 |38·0|21·3| 28·0| 14|N 12 E| ?  |   0 |   ..
  April    |756·0| +1·2 |39·9|23·6| 31·0| 13|N 18 E| ?  |   0 |   ..
  May      |754·8| +0·3 |43·0|27·2| 34·1| 19|N 63 W| 21 |   0 |   ..
  June     |756·0| +0·9 |41·5|26·5| 33·1| 27|S 12 W| 24 |   0 |   ..
  July     |757·1| +0·8 |39·0|23·4| 30·1| 47|S  4 W| 27 | 116 |   ..
  August   |756·2| -0·1 |39·1|24·7| 31·2| 46|S 12 W| 20 |   5 |   ..
  September|756·8| +1·2 |39·5|24·8| 30·0| 41|S 23 W| 23 |   2 |   ..
  October  |757·4| +0·5 |38·1|22·7| 29·7| 30|N 13 E| 22 |   0 |   ..
  November |758·1| +0·2 |29·1|18·7| 25·8| 26|N 30 E| 21 |   0 |   ..
  December |759·6| +0·9 |29·3|13·7| 21·0| 28|N 24 E| 22 |   0 |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |757·1| +0·4 |36·7|21·7| 28·3| 28|N 33 E| 23 | 123 |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1903
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |760·0| +1·2 |26·9|11·6| 18·6| 31|N  8 E| 23 |   0 |   ..
  February |761·5| +3·0 |28·2|12·6| 19·5| 32|N  8 W| 23 |   0 |   ..
  March    |760·5| +3·0 |32·6|15·1| 23·5| 18|N 15 W| 20 |   0 |   ..
  April    |757·0| +2·2 |39·9|20·8| 30·2| 18|N 37 E| 19 |   0 |   ..
  May      |757·7| +3·2 |40·9|24·7| 32·3| 28|S 43 E| 10 |  24 |   ..
  June     |757·4| +2·3 |41·4|25·8| 33·0| 28|S  7 W| 21 |   0 |   ..
  July     |758·1| +1·8 |38·7|25·1| 31·6| 36|S  1 W| 15 |  18 |   ..
  August   |758·1| +1·8 |37·5|24·3| 31·0| 44|S 30 W| 18 |  12 |   ..
  September|758·9| +3·3 |38·0|20·9| 30·1| 40|S 12 W| 15 |  14 |   ..
  October  |758·6| +1·7 |38·7|22·8| 30·3| 32|N  2 W| 15 |   0 |   ..
  November |759·9| +2·0 |36·9|20·9| 28·0| 32|N 15 E| 13 |   0 |   ..
  December |760·0| +1·3 |34·9|18·0| 25·2| 34|N 22 E| 13 |   0 |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |759·0| +2·4 |36·2|20·2| 27·8| 31|N 18 E| 18 |  68 |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1904
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |760·2| +0·8 |31·7|16·3| 22·8| 33|N 15 E| 13 |   0 |   ..
  February |760·4| +1·9 |31·9|16·6| 23·4| 26|N  6 E| 14 |   0 |    0
  March    |758·0| +0·5 |36·0|18·4| 26·6| 18|N 15 E| 17 |   0 |    0
  April    |758·0| +3·2 |38·8|20·2| 29·4| 16|N  1 E| 19 |   0 |    0
  May      |757·8| +3·3 |41·6|23·2| 32·6| 20|N  9 W| 17 |   0 |   --
  June     |758·5| +3·4 |42·6|25·6| 33·3| 25|S  2 W| 15 |   0 |  - 5
  July     |757·6| +1·3 |39·3|24·9| 32·1| 52|S 44 W| .. |  35 |  -20
  August   |758·3| +1·6 |39·9|25·8| 32·8| 50|S 28 W| .. |  76 |  +45
  September| ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  October  | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  November | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  December | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     | ..  |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  =========+=====+======+====+====+=====+===+======+====+=====+=========


TABLE LXXVIII.--_Station Berber._ (_Meteorological data_).

                                   1902
  =========+============+===============+===+=================+=========
    Month. | BAROMETER  |  THERMOMETER  |Hu-|       WIND      |RAINFALL
           |            |               |mi-|                 |IN MILLI-
           |            |               |di-|                 | METRES
           +-----+------+----+----+-----+ty.+------+----+-----+---------
           |Mean.|Varia-|Mean|Mean|Mean.|   |Direc-| Ve-|Fall.| Varia-
           |     | tion |max.|min.|     |   | tion.|loc-|     |  tion
           |     | from |    |    |     |   |      |ity.|     |  from
           |     | nor- |    |    |     |   |      |    |     |  nor-
           |     | mal. |    |    |     |   |      |    |     |  mal.
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. | ..  |    ..
  February |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. | ..  |    ..
  March    |756·3|  ..  |39·0|20·0| 29·5| 26|N  5 E| .. |  0  |    ..
  April    |755·9|  ..  |39·4|20·5| 30·0| 14|N  5 E| .. |  0  |    ..
  May      |755·6|  ..  |45·5|25·9| 35·7| 13|N 14 E| .. |  0  |    ..
  June     |755·6|  ..  |44·8|26·7| 35·8| 16|N 20 E| .. |  0  |    ..
  July     |757·1|  ..  |42·2|25·3| 33·8| 32|S 82 W| .. |  0  |    ..
  August   |  .. |  ..  |43·2|29·2| 36·2| 28|N 43 W| .. |  0  |    ..
  September|  .. |  ..  |48·3|26·9| 37·6| 31|S 23 W| .. |  0  |    ..
  October  |  .. |  ..  |39·3|23·4| 31·4| 40|N 39 E| .. |  0  |    ..
  November |  .. |  ..  |35·3|19·0| 27·2| 34|N  5 W| .. |  0  |    ..
  December |  .. |  ..  |33·0|14·7| 23·8| 40|N 15 W| .. | ..  |    ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. |  0  |    ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1903
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |  -- |  ..  |28·4|12·3| 20·4| 40|N 20 W| .. |  0  |    ..
  February |761·6|  ..  |29·4|13·0| 21·2| 34|N 23 W| .. |  0  |    ..
  March    |759·2|  ..  |34·3|11·0| 22·6| 22|N 16 W| .. |  0  |    ..
  April    |756·2|  ..  |44·7|15·7| 28·7| 27|N  5 W| .. |  0  |    ..
  May      |756·4|  ..  |43·1|20·4| 31·8| 35|N 63 E| .. |  0  |    ..
  June     |755·6|  ..  |45·2|21·0| 33·1| 58|N 20 W| .. |  0  |    ..
  July     |756·0|  ..  |42·9|21·0| 32·0| 57|N 56 W| .. |  0  |    ..
  August   |755·6|  ..  |43·7|19·0| 31·4| 58|N 76 W| .. |  0  |    ..
  September|757·1|  ..  |42·3|19·0| 30·6| 58|N 10 W| .. |  0  |    ..
  October  |757·6|  ..  |40·7|17·0| 28·8| 49|N 15 E| .. |  0  |    ..
  November |758·9|  ..  |36·5|14·1| 25·2| 64|N  7 E| .. |  0  |    ..
  December |758·9|  ..  |33·7|10·6| 22·2| 54|N  2 E| .. |  0  |    ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |755·6|  ..  |38·5|16·2| 27·3| 46|N 10 W| .. |  0  |    ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1904
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |759·1|  ..  | .. | .. | 20·9| 55|  N   | .. | --  |    --
  February |758·1|  --  |34·7|13·3| 24·2| 48|  N   | .. | --  |    --
  March    |755·7| -2·1 |35·0|16·4| 25·7| 35|N  2 W| .. | --  |    --
  April    |756·4| +0·4 |38·3|19·7| 29·0| 19|N  3 E| .. | --  |    --
  May      |756·3| +0·3 |41·8|24·9| 33·4| 25|N  9 E| .. | --  |    --
  June     |756·2| +0·6 |43·2|26·0| 34·6| 18|N 20 W| .. | --  |    --
  July     |755·8| -0·6 |42·1|27·0| 34·6| 33|S 16 W| .. | --  |    --
  August   |756·4| -0·3 |42·1|26·1| 34·1| 26|S 77 W| .. | --  |    --
  September|  .. |  ..  | .. | .. |  .. | ..|  ..  | .. | ..  |    ..
  October  |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. | ..  |    ..
  November |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. | ..  |    ..
  December |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. | ..  |    ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. | ..  |    ..
  =========+=====+======+====+====+=====+===+======+====+=====+=========


TABLE LXXIX.--_Station Assuân_ (_Meteorological data_).

                                   1902
  =========+============+===============+===+=================+=========
    Month. | BAROMETER  |  THERMOMETER  |Hu-|       WIND      |RAINFALL
           |            |               |mi-|                 |IN MILLI-
           |            |               |di-|                 | METRES
           +-----+------+----+----+-----+ty.+------+----+-----+---------
           |Mean.|Varia-|Mean|Mean|Mean.|   |Direc-| Ve-|Fall.| Varia-
           |     | tion |max.|min.|     |   | tion.|loc-|     |  tion
           |     | from |    |    |     |   |      |ity.|     |  from
           |     | nor- |    |    |     |   |      |    |     |  nor-
           |     | mal. |    |    |     |   |      |    |     |  mal.
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |765·6|  ..  |22·6| 8·5| 14·8| 50|  N   | 17 |  0  |    ..
  February |764·4|  ..  |30·6|11·4| 20·1| 23|  N   | 17 |  0  |    ..
  March    |761·3|  ..  |31·7|13·4| 22·0| 25|N  8 W| 18 |  0  |    ..
  April    |760·2|  ..  |35·5|18·2| 26·6| 23|N 15 W| 17 |  0  |    ..
  May      |759·7|  ..  |41·6|23·9| 32·6| 16|N  5 W| 21 |  0  |    ..
  June     |757·7|  ..  |41·7|23·3| 32·4| 20|N  6 W| 19 |  0  |    ..
  July     |757·6|  ..  |41·3|24·0| 32·5| 20|N 50 W| 17 |  0  |    ..
  August   |757·2|  ..  |41·4|23·9| 32·5| 20|N 15 W| 18 |  0  |    ..
  September|758·9|  ..  |41·2|23·9| 31·6| 32|N 18 W| 18 |  0  |    ..
  October  |761·9|  ..  |37·9|21·1| 28·5| 41|N  1 W| 18 |  0  |    ..
  November |764·0|  ..  |29·0|14·2| 20·8| 43|  N   | 20 |  0  |    ..
  December |766·6|  ..  |23·8| 9·2| 14·3| 52|N  2 W| 19 |  0  |    ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |761·3|  ..  |34·8|17·9| 25·7| 30|N 10 W| 18 |  0  |    ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1903
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |767·7|  ..  |22·0| 8·5| 13·6| 56|  N   | 17 |  0  |    ..
  February |768·3|  ..  |23·7| 9·1| 15·1| 44|  N   | 19 |  0  |    ..
  March    |764·6|  ..  |28·1|12·7| 19·0| 38|  N   | 21 |  0  |    ..
  April    |760·1|  ..  |37·3|18·8| 26·3| 32|  N   | 22 |  0  |    ..
  May      |768·9|  ..  |40·9|22·9| 28·6| 35|N  4 E| 17 |  0  |    ..
  June     |757·5|  ..  |41·3|24·2| 31·6| 23|N  1 E| 22 |  0  |    ..
  July     |756·8|  ..  |41·5|24·3| 31·9| 22|N  1 W| 19 |  0  |    ..
  August   |756·2|  ..  |43·5|25·4| 31·7| 25|  N   | 21 |  0  |    ..
  September|757·5|  ..  |41·4|22·3| 28·8| 30|  N   | 19 |  0  |    ..
  October  |758·6|  ..  |39·5|19·5| 26·4| 34|  N   | 19 |  0  |    ..
  November |761·1|  ..  |34·6|14·9| 21·2| 38|  N   | 17 |  0  |    ..
  December |761·5|  ..  |30·0|11·6| 17·8| 46|  N   | 17 |  0  |    ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |761·6|  ..  |35·3|17·8| 24·3| 35|  N   | 19 |  0  |    ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1904
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |762·3|  ..  |24·7| 8·1| 14·7| 48|  N   | 18 |  0  |    ..
  February |762·5|  ..  |27·1|10·1| 16·8| 43|  N   | 17 |  0  |    ..
  March    |759·9|  ..  |31·1|13·1| 20·4| 31|  N   | 22 |  0  |    ..
  April    |758·8|  ..  |34·1|17·1| 24·3| 28|N  5 W| 19 |  0  |    ..
  May      |758·6|  ..  |36·5|19·9| 27·3| 26|N  5 E| 23 |  0  |    ..
  June     |757·8|  ..  |40·2|23·0| 31·2| 23|N 22 W| 19 |  0  |    ..
  July     |755·9|  ..  |40·4|24·4| 32·4| 27|  N   | .. |  0  |    ..
  August   |755·8|  ..  |36·1|23·7| 29·9| 34|  N   | .. |  0  |    ..
  September| ..  |  ..  | .. | .. |  .. | ..| ..   | .. | ..  |    ..
  October  | ..  |  ..  | .. | .. |  .. | ..| ..   | .. | ..  |    ..
  November | ..  |  ..  | .. | .. |  .. | ..| ..   | .. | ..  |    ..
  December | ..  |  ..  | .. | .. |  .. | ..| ..   | .. | ..  |    ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     | ..  |  ..  | .. | .. |  .. | ..| ..   | .. | ..  |    ..
  =========+=====+======+====+====+=====+===+======+====+=====+=========


TABLE LXXX.--_Station Cairo_ (_Meteorological data_).

                                   1902
  =========+============+===============+===+=================+=========
    Month. | BAROMETER  |  THERMOMETER  |Hu-|       WIND      |RAINFALL
           |            |               |mi-|                 |IN MILLI-
           |            |               |di-|                 | METRES
           +-----+------+----+----+-----+ty.+------+----+-----+---------
           |Mean.|Varia-|Mean|Mean|Mean.|   |Direc-| Ve-|Fall.| Varia-
           |     | tion |max.|min.|     |   | tion.|loc-|     |  tion
           |     | from |    |    |     |   |      |ity.|     |  from
           |     | nor- |    |    |     |   |      |    |     |  nor-
           |     | mal. |    |    |     |   |      |    |     |  mal.
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |765·5| +0·8 |17·2| 7·2| 11·3| 77|N 06 W| 6·5|  5  |   -2
  February |764·9| +1·0 |22·8| 8·8| 14·7| 69|N 28 W| 6·1|  6  |   +3
  March    |761·8| -0·5 |24·2|10·1| 16·0| 62|N 48 W| 8·6|  1  |   -4
  April    |760·4| -0·4 |28·8|13·4| 20·0| 56|N 10 W|10·9|  0  |   -2
  May      |761·6| +1·2 |33·4|16·3| 23·9| 47|N  8 W|14·9|  0  |   -2
  June     |759·6| -0·2 |35·1|18·6| 25·8| 50|N 20 W|11·4|  0  |    0
  July     |758·0| +0·6 |36·1|20·1| 27·0| 55|N 18 W| 4·3|  0  |    0
  August   |758·2| +0·3 |35·6|20·4| 26·8| 62|N 12 E| 5·0|  0  |    0
  September|760·3| -0·4 |33·0|19·2| 24·9| 70|N 27 E| 3·7|  0  |    0
  October  |762·9| +0·5 |31·0|17·0| 22·8| 71|N 15 E| 5·6|  0  |   -1
  November |763·0| -1·3 |24·0|13·6| 17·9| 67|S 59 W| 3·1|  0  |   -6
  December |765·5| +0·8 |18·6| 8·5| 12·6| 69|S 35 W| 3·7|  1  |   -5
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |761·8| +0·2 |28·3|14·4| 20·3| 63|N 24 W| 7·0| 13  |  -19
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1903
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |767·2| +2·5 |17·7| 6·0| 10·7| 80|N 36 W| 5·1|  2  |   -5
  February |767·6| +3·7 |18·7| 6·2| 11·3| 72|S 68 W| 5·6|  2  |   -1
  March    |764·2| +1·9 |22·3| 9·3| 14·7| 69|N 20 W| 7·7|  8  |   +3
  April    |760·4| -0·4 |29·6|13·6| 20·3| 57|N  3 E| 9·3|  1  |   -1
  May      |761·7| +1·3 |34·0|15·4| 22·6| 47|N 22 E|12·0|  0  |   -2
  June     |759·4| -0·4 |34·8|18·5| 26·1| 49|N 21 E|12·0|  0  |    0
  July     |758·4| +1·0 |34·6|19·7| 26·1| 60|N  7 W|10·0|  0  |    0
  August   |757·8| -0·1 |34·7|20·7| 26·6| 62|N 14 W| 6·0|  0  |    0
  September|761·4| +0·7 |30·7|18·1| 23·4| 72|N  4 W| 6·0|  0  |    0
  October  |763·7| +1·3 |28·0|15·1| 20·5| 74|N 10 E| 6·4|  0  |   -1
  November |764·9| +0·6 |23·1|10·7| 16·0| 68|N 12 E| 6·1|  0  |   -6
  December |764·3| -0·4 |20·1| 7·8| 12·8| 76|N 72 E| 4·4| 10  |   +4
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |762·6| +1·0 |27·4|13·4| 19·3| 65|N  2 W| 7·5| 23  |   -9
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1904
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |763·8| -0·9 |19·3| 6·9| 11·3| 73|N 39 E|18·5|  9  |   +2
  February |763·7| -0·2 |23·2| 7·6| 13·7| 74|S 26 W|16·6| 19  |  +16
  March    |760·7| -1·6 |23·8| 9·6| 15·2| 73|N 51 W|16·6|  0  |   -5
  April    |760·4| -0·4 |27·6|12·0| 18·5| 72|N 34 E|17·1| 16  |  +14
  May      |760·4|  0   |31·7|15·4| 22·2| 65|N 29 W|14·8|  1  |    0
  June     |759·2| -0·6 |34·2|17·9| 25·0| 59|N 30 W|12·4|  0  |    0
  July     |756·6| -0·6 |34·9|19·5| 27·2| 68|N  8 W| .. |  0  |   ..
  August   |758·2| -0·6 |34·6|19·5| 27·0| 77|N 14 W| .. |  0  |   ..
  September|  .. |  ..  | .. | .. |  .. | ..|  ..  | .. | ..  |   ..
  October  |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. | ..  |   ..
  November |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. | ..  |   ..
  December |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. | ..  |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. | ..  |   ..
  =========+=====+======+====+====+=====+===+======+====+=====+=========


TABLE LXXXI.--_Station Alexandria._

                                   1902
  =========+============+===============+===+=================+=========
    Month. | BAROMETER  |  THERMOMETER  |Hu-|       WIND      |RAINFALL
           |            |               |mi-|                 |IN MILLI-
           |            |               |di-|                 | METRES
           +-----+------+----+----+-----+ty.+------+----+-----+---------
           |Mean.|Varia-|Mean|Mean|Mean.|   |Direc-| Ve-|Fall.| Varia-
           |     | tion |max.|min.|     |   | tion.|loc-|     |  tion
           |     | from |    |    |     |   |      |ity.|     |  from
           |     | nor- |    |    |     |   |      |    |     |  nor-
           |     | mal. |    |    |     |   |      |    |     |  mal.
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |764·5| +0·8 |18·3|10·3| 13·3| 70|N 52 W| 22 | 104 |  +50
  February |764·4| +1·4 |22·3|12·6| 15·9| 69|N 45 E| 18 |   8 |  -14
  March    |761·3| -0·5 |20·6|13·0| 15·8| 68|N 15 W| 19 |   4 |  -13
  April    |760·4| -1·1 |22·8|14·9| 17·8| 71|N  8 E| 18 |   5 |   +3
  May      |762·0| +1·5 |26·8|18·2| 20·9| 64|N 20 E| 16 |   0 |  -13
  June     |759·9| -0·6 |27·1|18·6| 22·1| 72|N  5 W| 17 |   0 |    0
  July     |758·1| +0·1 |30·4|21·7| 24·2| 73|N 28 W| 18 |   0 |    0
  August   |758·5| -0·1 |31·8|23·3| 25·1| 73|N  7 W| 18 |   0 |    0
  September|760·4| -0·5 |32·4|22·5| 24·6| 70|N  6 E| 18 |   0 |   -1
  October  |763·0| +0·4 |27·9|20·7| 23·0| 74|N 40 E| 16 |   5 |   -4
  November |762·2| -1·8 |23·4|15·2| 18·0| 72|N 60 W| 17 |  36 |   -3
  December |764·3| +0·4 |18·1|10·8| 13·5| 74|S 71 W| 23 |  92 |  +12
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |761·6|  0   |25·2|16·9| 19·5| 71|N 11 W| 19 | 254 |  +27
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1903
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |766·6| +2·9 |16·7| 9·8| 12·7| 78|N  6 E| 18 |  90 |  +36
  February |767·0| +4·0 |17·8|10·3| 13·2| 72|N 52 W| 18 |  34 |  +12
  March    |763·8| +2·0 |19·5|11·8| 14·8| 72|N  4 E| 21 |  14 |   -3
  April    |760·5| -1·0 |24·2|13·7| 17·1| 72|N 30 E| 21 |   1 |   -2
  May      |762·2| +1·7 |25·9|16·8| 20·6| 70|N 25 E| 18 |   0 |  -13
  June     |759·8| -0·7 |27·8|18·5| 22·0| 74|   N  | 22 |   0 |    0
  July     |758·5| +0·5 |29·1|20·1| 23·7| 74|N 22 W| 26 |   0 |    0
  August   |757·7| -0·9 |30·8|20·6| 24·4| 78|N 17 W| 21 |   0 |    0
  September|761·4| +0·5 |30·0|18·9| 23·3| 68|N  2 W| 22 |   0 |   -1
  October  |763·6| +1·0 |27·2|17·1| 21·0| 70|N 17 E| 21 |   0 |   -9
  November |764·5| +0·5 |23·6|13·1| 17·1| 72|N  2 E| 25 |  10 |  -28
  December |763·7| -0·2 |21·3|11·4| 15·2| 76|N 62 W| 18 |  24 |  -57
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |762·4| +0·8 |24·5|16·0| 18·6| 73|N  5 W| 21 | 173 |  -65
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
                                   1904
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  January  |763·9| +0·2 |18·5| 9·1| 12·4| 76|N  3 E| 23 |  63 |   +9
  February |763·9| +0·9 |21·0|10·2| 13·8| 79|N 13 W| 21 |  13 |  -10
  March    |760·8| -1·0 |21·2|11·4| 14·5| 77|N  8 E| 29 |   1 |  -16
  April    |761·6| -0·1 |23·1|13·4| 16·2| 82|N 12 W| 28 |   2 |    0
  May      |761·5| +1·0 |26·2|16·3| 18·8| 85|N  3 W| 24 |  -- |  -13
  June     |760·4| -0·1 |28·5|19·2| 21·9| 83|N 12 W| 28 |   0 |  - 0
  July     |756·5| +0·4 |30·2|21·0| 25·6| 73|N 40 W| 25 |   0 |   -0
  August   |758·2| +0·5 |30·7|21·4| 26·0| 72|N 12 W| 25 |   1 |   +1
  September|  .. |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  October  |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  November |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  December |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  ---------+-----+------+----+----+-----+---+------+----+-----+---------
  Mean     |  .. |  ..  | .. | .. |  .. | ..|  ..  | .. |  .. |   ..
  =========+=====+======+====+====+=====+===+======+====+=====+=========




INDEX


  A
  Abai river, 13
  Abu Zeid ford, 42
  Abydos spring level, 67
  Abyssinia, 13, 19, 43
  Adarma, 45
  Addis Ababa, 16, 20, 44, 214
  Aird, Sir John, 75
  Akobo, 37
  Albert Lake, 11, 12, 14, 15, 18, 29, 30, 31
  ---- ---- reservoir, 81, 82, 87, 90
  ---- ---- tributaries, 31
  Albert Nile in 1841, 38
  ---- ---- catchment basin, 17, 119
  ---- ---- description, 31-35
  ---- ---- observed discharges, 129-134
  ---- ---- discharges, 22, 56, 81, 82, 93
  ---- ---- discharge table, 144, 145
  ---- ---- gauges, 168-174
  ---- ---- projects, 58, 81, 89-92
  ---- ---- slopes, 14, 120
  ---- ---- tributaries, 31, 32, 34
  ---- ---- velocities, 15, 121
  Alexandria, 20, 220
  Ambatch, 31, 92
  Amenemhat, 47, 66, 79
  Analysis of water and soil, 62, 100-101
  Anderson, Mr. Lang, 64
  Appendices, 117
  Arab, Bahr el, 36
  Assiout Weir, 49, 150
  Asua River, 32
  Assuân gauge compared to Bombay rainfall, 213
  ---- dam, 48, 61, 75, 76, 77, 87, 89
  ---- distances from and to, 124, 125
  ---- discharges, 25, 58-60, 139-142
  ---- discharge table, 150
  ---- gauges, 48, 52, 94, 97, 98, 153, 158, 164-166, 194-202, 209
  ---- meteorological data, 20, 218
  Atem river, 32, 33, 90
  Atbara river, catchment basin, 17, 19, 119
  ---- ---- description, 13, 45, 69
  ---- ---- discharges, 24, 47, 58, 60, 138-140
  ---- ---- discharge table, 149
  ---- ---- gauges at Khashm el Girba, 188, 189
  ---- ---- tributaries, 45

  B

  Baharia Oasis, 109
  Baker, Sir Benjamin, 75
  Baker, Sir Samuel, 11, 34, 39, 40
  Barometric readings, 215-220
  Barois, M. J., 61, 62
  Barrages, The, 50, 53, 54, 74, 82, 99, 123, 124, 151, 152, 207, 208
  Basalt, 22, 114
  Basin irrigation, 59, 65, 66, 67, 68, 79, 93, 94, 99, 100, 159-166
  ---- ---- in the Sudan, 102
  Beadnell, Mr. H. G. F., 107
  Beresford, Mr. J. S., 89
  Berkeley, Fort, 31
  Berber, 46, 217
  ---- gauges, 190-193
  Blue Nile, catchment basin, 17, 119
  ---- ---- description, 12, 13, 18, 21, 41, 43, 61
  ---- ---- observed discharges, 129, 136, 137
  ---- ---- discharges, 24, 46, 57, 60, 139-141
  ---- ---- discharge table, 147, 148
  ---- ---- distances along, 128
  ---- ---- gauges, 179-182, 183-187
  ---- ---- projects, 43, 44, 103
  ---- ---- slope, 15
  ---- ---- tributaries, 44
  ---- ---- velocities, 44
  Bombay, 20, 213
  Bor, 32, 89, 99
  Brown, Sir Hanbury, 66, 77, 79, 89, 99

  C

  Cairo, 16, 20, 22, 24, 25, 50, 52, 53, 59, 94, 97, 98, 142, 150, 158,
  164-166, 219
  ---- gauges, 203-206, 210
  Cassel, Sir Ernest, 75
  Cataracts, 14, 46, 47, 48, 88, 102, 103
  Catchment basins, 16, 18, 119
  Chapters, 11, 26, 56, 73, 107
  Chavanne, Joseph, 12
  Chélu Bey, 5
  Choga, Lake, 15, 28, 30, 121, 122
  Clifton, Mr. C., 77
  Climate of the Nile Valley, 18, 27, 102, 214-220
  Congo forest, 29
  Conversion tables for pics and metres, 211, 212
  Corvée, 70
  Cotton, 82, 88, 102, 103, 104
  Course of the Nile, 12
  Cretaceous, 111
  Cromer, Lord, 100
  Cultivated area of Egypt, 73

  D

  Dakhla Oasis, 107
  Damer, El, 13, 45
  Damietta branch, 14, 15, 53, 54, 60, 61, 70, 85, 123, 139, 140
  ---- ---- discharge table, 152
  ---- ---- gauges, 208
  Darfur, 17
  D’Arnaud, 38
  De Gottberg, 47
  De la Motte, 74
  Didessa, 44
  Dinder river, 17, 21, 44, 101
  Diodorus Siculus, 78
  Discharges observed, 129-138
  Discharge table for Assuân, Assiout & Cairo, 150
  ---- ---- ---- Damietta branch, 152
  ---- ---- ---- Duem, 146
  ---- ---- ---- Gondokoro, 144
  ---- ---- ---- Khashm el Girba, 149
  ---- ---- ---- Khartoum, 148
  ---- ---- ---- Mongalla, 145
  ---- ---- ---- Ripon Falls, 143
  ---- ---- ---- Rosetta branch, 151
  ---- ---- ---- Sobat river, 145
  ---- ---- ---- Tewfikia, 146
  ---- ---- ---- Wadelai, 144
  ---- ---- ---- Wady Haifa, 151
  Distances of places along the Damietta and Rosetta branches, 123
  Distance Barrage to Assuân, 124
  ---- Assuân to Khartoum, 125
  ---- Khartoum to Gondokoro, 126
  ---- Gondokoro to the Ripon Falls, 127
  -- Khartoum to Rosaires, 128
  Discharges, 18, 22, 56-60, 81-84, 90, 95, 139-142, 159-163
  ---- Victoria Nile, 27
  ---- Semliki river, 29
  ---- Lake Albert, 29
  ---- Albert Nile, 32-34
  ---- Gazelle river, 35
  ---- Zeraf river, 36
  ---- Sobat river, 37
  ---- White Nile, 41
  ---- Blue Nile, 43-44
  ---- Atbara, 45
  Discharges Nile at Khartoum, 46
  ---- ---- ---- Assuân, 49
  ---- ---- ---- Cairo, 52
  ---- ---- ---- Rosetta and Damietta branches, 55
  Dongola, 47
  Drainage, 69
  Drury, Lt., R.N., 41
  Duem, 42, 43, 46, 57, 135, 141, 146, 178
  Dueru, Lake, 29
  Dufile, 13, 31, 90
  Dulaib Hilla. 37, 134, 145, 176
  Dupuis, Mr. C., 5, 43, 44, 101, 103

  E

  Eads, Mr., 86
  Edku, Lake, 64
  Edward, Lake Albert, 12, 29
  ---- ---- ---- tributaries, 29
  Egypt, 25, 73, 85, 87, 88, 93, 99, 100
  Emin Pasha, 40
  Electrical development possible, 28, 29, 31, 103
  Elephantine Island, 48
  Eocene, 112
  Esna shales, 112,
  Evaporation, 27, 30, 41, 43, 44, 96

  F

  Farafra, 110
  Fayoum, The, 66, 79, 81
  Fitzmaurice, Mr. Maurice, 75
  Floods, 70, 71, 72, 85, 87, 88, 98
  Foaden, Mr. G. P., 61, 63, 103
  Fola Rapids, 14, 31
  Fowera, 14, 28
  Fuller, Mr. J. B., 69

  G

  Gaash river, 21, 45, 46, 101, 103
  Gage’s channel, 34
  Garak depression, 81
  Garstin, Sir W. E., 5, 11, 12, 26, 29, 32, 41, 75, 82, 83, 85, 88, 89,
  91, 92, 99, 101
  Gauges, 48, 50, 51, 52, 53, 117, 153
  ---- Assuân, 194-201, 209
  ---- Assuân Reservoir, 202
  ---- Berber, 190-193
  ---- Cairo, 203-206
  ---- Damietta branch, 208
  ---- Duem, 178
  ---- Dulaib Hilla, 176
  ---- Gondokoro, 169-172
  ---- Jinja, 166
  ---- Khartoum, 183-187
  ---- Khasm el Girba, 188-189
  ---- Mongalla 173-174
  ---- Nasser, 175
  ---- Rosetta branch, 207
  ---- Tewfikia, 177
  ---- Wad Medani, 179-182
  ---- Wadelai, 168
  Gazelle river, 13, 15, 16, 17, 18, 19, 23, 35, 40, 56, 83, 129, 133
  ---- ---- discharges, 139, 140
  ---- ---- tributaries, 36
  Gebel, Bahr-el-, 12
  Gebelain, 42
  Geology, 21, 110
  Gessi Pasha, 40
  Gezireh, 100, 102, 103
  Ghaba Shambe, 32, 37, 41
  Gold, 114
  Gondokoro, 23, 32, 56, 90, 91, 119, 122, 126, 127, 139, 140, 141
  ---- gauges, 169-172
  ---- discharge table, 144
  Gordon, 40
  Gosrejeb, 45
  Green water, 61
  Granites, 21, 111

  H

  Hansard, Mr., 5
  Herodotus, 78, 80
  Hewat, Mr. Marshal, 77
  Hillet Nuer, 33, 34, 40, 83, 84
  Hughes, Mr. Frank, 64, 100

  I

  Ibrahim Effendi Fehmy, 105
  Igneous rocks, 111
  Infiltration, 53, 59, 60, 81, 84, 90
  Introduction, 11
  Irrigation, 65, 66, 68, 69, 93, 96, 97, 99, 102, 105, 106, 108, 109,
  110, 159-163.
  Ismail Pasha Ayub, 40

  J

  Jinja gauge, 167

  K

  Kafr Zayat, 54
  Kagera river, 12, 26, 28
  Kalabsha, 74
  Kamlin, 21, 24, 46
  Kankar, 21
  Karanain, 54
  Kassala, 46
  Kharga oasis, 109
  Khartoum 13, 14, 15, 20, 21, 24, 43, 44, 46, 57, 60, 100, 135-142, 216
  ---- distances to and from, 125, 126, 128
  ---- discharge table, 148
  ---- gauges, 183-187
  Khasm el Girba, 45, 138
  ---- discharge table, 149
  ----- gauges 188, 189
  Kit river, 32
  Kom Ombos, 22, 113
  Kordofan, 17
  Kushesha, 78

  L

  Lado, 40
  Lepsius, 47
  Letheby, 61, 62
  Linant Pasha, 42, 55
  Limestone, 22, 114
  ---- Nodular, 21
  Lolle, 35, 84
  Lombardini, Elia, 5, 11, 12, 38, 60
  Luxor, 22
  Lyons, Capt. H.G., 5, 11, 18, 21, 26, 27, 33, 44, 84

  M

  Mackenzie, Dr., 62
  Manures, 63, 69
  Marno, Signor, 40, 84
  Martyr, Col., 41
  Mean low water levels, 94, 158
  Megahid channel, 35
  Mehemet Ali, Viceroy, 38, 54, 68, 73, 74
  Menes, 79
  Meteorological data, 214-220
  Miocene, 113
  Mississippi river, 33
  Mœris Lake, 66, 74, 76, 78, 81
  Mongalla, 132
  ---- discharge table, 145
  ---- gauges, 173,174

  N

  Napoleon, 48
  Nasser, 37
  -- gauge, 175
  Navigation, 14, 28, 32, 44
  Nero, 38
  Nile, The, 11, 12, 15, 16, 18, 21, 46, 47, 49, 56, 58-61, 67, 93, 99,
  164-166
  ---- discharge tables, 150,158
  ---- distances along, 124, 125
  ---- gauges, 190-206
  ---- slopes, 120
  ---- velocities, 121-122
  Nitrates, 22, 69, 115
  No, Lake, 14, 34, 35, 82, 83, 84
  Nomenclature, 12

  O

  Oases, 107
  Omdurman, 43

  P

  Papyrus, 31, 32, 42
  Payen, Champion and Gastinel, 63
  Peake, Major, R. A., 41
  Peat, 21
  Percolation, see Infiltration.
  Perennial irrigation, 59, 68, 69, 88, 93
  Phosphates, 22, 115
  Pibor river, 37
  Pics converted to metres, 98, 209, 210
  Plates, List of, 9
  Pliocene, 113
  Porphyry, 114
  Projects, 44, 58, 73, 84
  ---- Raising Assuân dam, 75
  ---- Wady Rayan Reservoir, 76
  ---- Lake Albert Reservoir and river training, 81
  ---- Flood protection for Egypt, 85
  ---- Complete for the Nile, 87
  ---- Sir William Garstin’s projects, 89
  ---- Conversion of basin to perennial irrigation, 93
  ---- Development of the Sudan, 100
  Prompt, M., 74

  R

  Rahad river, 17, 21, 44, 101
  Rainfall, 17-21, 27, 30, 41, 43, 45, 56, 59, 103, 213
  ---- tables, 214-220
  Rameses, 48, 86
  Red water, 61, 75
  Reservoirs, 30, 73, 75, 76, 77
  Ripon Falls, 12, 27, 28, 127, 139-141, 143, 166
  Roda gauge, 50
  ---- gauges, 203-206
  Rohl river, 36
  Rosaires, 13, 14, 44, 128
  Rosetta branch, 14, 15, 33, 53, 60, 61, 85, 86, 87, 89, 139, 140
  ---- ---- discharge table, 151
  ---- ---- distances, 123
  ---- ---- gauges, 207
  ---- ---- velocities, 121
  Ross, Col. Justin, 77
  Rudolf, Lake, 16
  Ruenzori, Mountain, 16, 21, 29

  S

  Salaama river, 13, 45
  Sandstone, Nubian, 24, 112, 114
  Sayce, Rev., Professor, 79
  Schweinfurth, Dr., 36, 39, 85
  Scott-Moncrieff, Sir Colin, 3, 74
  Scour and deposit of silt, 44, 92, 95, 99
  Semliki river, 12, 29
  Sennaar, 14, 44
  Semna Cataract, 47
  Sesostris, 66
  Settit river, 13, 45
  Silsila, 21, 74, 112
  Slopes, 14, 47, 48, 49, 53, 120, 157
  Sobat River, 12, 13, 15, 23, 35, 36, 37, 56, 61, 82, 84, 119, 129,
  134, 139-141
  ---- ---- discharge table, 145
  ---- ---- gauges, 175, 176
  ---- ---- slopes, 120
  ---- ---- velocities, 121
  ---- ---- tributaries, 37
  Soil analysis, 45, 61, 63, 64, 100, 101
  Sparkes, Col., 40
  Speke and Grant, 11
  Strabo, 78
  Storage, see Projects
  Suakin-Khartoum railway, 100
  Subject matter, 7, 8
  Subsoil water, 63, 67
  Sudan, 88, 100, 102, 103, 105, 106
  Sudd region, 13, 16, 33, 34, 35, 37, 38, 39, 41, 56, 57, 58, 82, 83

  T

  Temperatures, 19, 20, 21, 214-220
  Tewfikieh, 41, 134, 139, 140, 141
  ---- discharge table, 146
  ---- gauge, 177
  Thebes, 67
  Tributaries of Lake Albert, 31
  ---- ---- the Albert Nile, 31, 32, 34
  ---- ---- ---- Atbara, 45
  ---- ---- ---- Blue Nile, 44
  ---- ---- ---- Lake Edward, 29
  ---- ---- ---- Gazelle river, 36
  ---- ---- ---- Sobat river, 36
  ---- ---- ---- Lake Victoria, 28
  ---- ---- ---- Victoria Nile, 29
  Trough of the Nile, cubic contents, 155
  Tsana Lake, 13, 15, 43, 45, 88, 103, 129
  Tumat river, 44

  U

  Uganda, 29, 130

  V

  Velocities, 14, 33, 45, 49, 121
  Victoria, Lake, 11, 12, 14, 17, 18, 26
  ---- ---- discharge table, 143
  ---- ---- gauges, 167
  ---- ---- tributaries, 28
  Victoria Nile, 12, 14, 15, 22, 28, 130, 139, 140, 141
  ---- ---- discharge table, 143
  ---- ---- gauges, 167
  ---- ---- distances, 127
  ---- ---- slopes, 120
  ---- ---- tributaries, 29
  ---- ---- velocities, 121
  Vœlcker, Dr., 64

  W

  Wadelai, 16, 31, 90, 139-141
  ---- discharge table, 144
  ---- gauges, 168
  Wad Medani, 20, 44, 136, 137, 215
  ---- ---- discharge table, 147
  ---- ---- gauges, 179-182
  Wady Halfa, 14, 15, 48, 139-141
  Wadi Halfa discharge table, 151
  Wady Natrûn, 115
  Wady Rayan, 74, 76, 77, 80, 81, 85, 87, 88
  Water, Analysis of, 62, 63, 67
  Watersheds, 16
  Webb, Mr. A., 89
  Weeds, 29
  Wells, 108
  Werne, M., 38
  Western, Lt.-Col. J. H., 74, 77
  White Nile, 12, 13, 15, 16, 18, 19, 23, 32, 36, 38, 41, 43, 46, 56,
  60, 61, 84, 119, 129, 134, 135, 139-141
  ---- ---- distances on 126
  ---- ---- discharge tables, 146
  ---- ---- gauges, 177, 178
  ---- ---- slope, 120
  ---- ---- velocities, 121
  Whitehouse, Commander, 26
  Whitehouse, Mr. Cope, 74
  Winds, 19, 20, 27, 214-220

  Y

  Yei river, 34

  Z

  Zeraf river, 13, 33, 34, 36-40, 84, 92, 94, 129, 133
  ---- discharges, 36, 133




  Transcriber’s Notes

  Inconsistent, archaic and unusual transcriptions, spelling,
  hyphenation, punctuation, use of accents, etc. (including in names)
  and repeated information have been retained (even when occurring on
  the same page or in the same sentence), except as mentioned below. The
  use of periods, mid-level decimal points and commas in numbers has not
  been standardised.

  Plate II: the data as mentioned in the errata have not been corrected
  in the Plate.

  Page 51-52, table, last column: 199 and 1877 are not in the range of
  years under consideration.

  Page 97, table header: the years are out of order, possibly
  erroneously.

  Page 203: the table header does not appear to agree with the contents;
  presumably, the first group of rows refers to 1876.

  Page 209, column Pic 16, row 14: 4·11 does not fit with the other data
  and may be an error for 8·11

  In the source document, the Plates are not always printed in numerical
  order (see also the List of Plates), this has not been changed.

  Unless mentioned below under “Changes Made”, all (tabulated or text)
  data and calculations are presented as printed in the source document,
  even when there are obvious errors or inconsistencies in these data or
  calculations.


  Changes made

  Some footnotes, tables and illustrations moved; some tables re-
  arranged.
  Some minor obvious typos have been corrected silently.
  R.L. and R. L. have been standardised as R. L., spaces between numbers
  and percent signs have been removed where present.
  Appendices: the numbering of some of the tables has been corrected,
  some minor lay-out inconsistencies have been resolved.
  page 12: Afrika’s Ströme and Flüsse changed to Afrikas Ströme und Flüsse
  page 32: Fort Barkeley changed to Fort Berkeley as elsewhere
  page 36: 15. The Sobat River changed to 16. The Sobat River
  page 70, Section 30: italics changed to bold as with other headings
  page 72, calculations: Total materials taken out of category Materials
  not paid for
  page 74: Mehemet Aly changed to Mehemet Ali as elsewhere
  page 119: Absynian Hills changed to Abyssinian Hills
  page 128, table header: column 2, Gondokoro changed to Khartoum;
  column 3, Khartoum changed to Rosaires
  page 129-130: these pages were reversed in the printed book
  page 145: Dulab Hilla changed to Dulaib Hilla as elsewhere
  page 160: Sobagia changed to Sohagia; Shekha changed to Shekhia
  pages 168, 175-178, 188-189, 194, 202-203, 207-208 table headings:
  names of months have been abbreviated
  Index (to conform to text): Kashm changed to Khasm as in text (several
  times); Emim Pasha changed to Emin Pasha.