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[Illustration]




SCIENTIFIC AMERICAN SUPPLEMENT NO. 401




NEW YORK, SEPTEMBER 8, 1883

Scientific American Supplement. Vol. XVI, No. 401.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.


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TABLE OF CONTENTS.

I.    CHEMISTRY.--On the Different Modifications of Silver Bromide
      and Silver Chloride.

      Analysis of New Zealand Coal.

      On the Determination of Manganese in Steel, Cast Iron,
      Ferro-manganese, etc.

      Manganese and its Uses.

      Ozokerite or Earth-wax. By WILLIAM L. LAY. A valuable
      and instructive paper read before the New York Academy of
      Sciences.--Showing the nature, sources, and applications of this
      remarkable product.

      On the Constitution of the Natural Fats.

II.   ENGINEERING AND MECHANICS.--Improved Spring wheel
      Traction Engine.--With two engravings.

      An Improved Iron Frame Gang Saw Mill.--With one large
      engraving.

      The Heat Regenerative System of Firing Gas Retorts.--Siemens'
      principle.--As operated at the Glasgow Corporation Works.--With
      two engravings.

      A New Gas Heated Baker's Oven.

III.  TECHNOLOGY.--How to Produce Permanent Photographic Pictures
      on Terra Cotta, Glass, etc.--With recipes and full directions.

      How to Make Paper Photo Negatives.--Full directions.

      Some of the Uses of Common Alum.

      An Improved Cloth Stretching Machine.--With an engraving.

      Purification of Woolen Fabrics by Hydrochloric Acid Gas.

      Apparatus for Preventing the Loss of Carbonic Acid in Racking
      Beer.--With an engraving.

IV.   ELECTRICITY.--Application of Electricity to the Bleaching of
      Vetable Textile Materials.--With figure of apparatus.

      Table Showing the Relative Dimensions, Lengths, Electrical
      Resistances, and Weights of Pure Copper Wires.

V.    ASTRONOMY.--The Solar Eclipse of 1883.--An interesting abstract
      from a report of C. S. HASTINGS (Johns Hopkins University), of
      the American Astronomical Exhibition to the Caroline Islands.

VI.   NATURAL PHILOSOPHY.--Recent Experiments Affecting the
      Received Theory of Music.--An interesting paper descriptive of
      certain experiments by President Morton, of Stevens Institute.

      The Motions of Camphor upon Water.--With an engraving.

VII.  ARCHITECTURE.--Suggestions in Village Architecture.--
      Semidetached villas.--Bloomfield crescent.--With an engraving.

      Specimens of Old Knocking Devices for Doors.--Several figures.

VIII. ARCHÆOLOGY.--A Buried City of the Exodus.--Being an account
      of the recent excavations and discoveries of Pithom
      Succoth, in Egypt.--With an engraving.

      The Moabite Manuscripts.

IX.   AGRICULTURE. HORTICULTURE, ETC.--The Queen Victoria
      Century Plant.--With an engraving.

      Charred Clover.

      A New Weathercock.--With one figure.

X.    MISCELLANEOUS.--New Monumental Statue and Landing Place
      in Honor of Christopher Columbus at Barcelona, Spain.--With an
      engraving.

      Scenery on the Utah Line of the Denver and Rio Grande Railway.

      Captain Matthew Webb.--Biographical sketch.--With portrait.

      The Dwellings of the Poor In Paris.

      Shipment of Ostriches from Cape Town, South Africa.--With one
      page of engravings.

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MONUMENT TO CHRISTOPHER COLUMBUS, AT BARCELONA, SPAIN.


The cultivated and patriotic city of Barcelona is about to erect
a magnificent monument in honor of Columbus, the personage most
distinguished in the historic annals of all nations and all epochs.
The City of Earls does not forget that here the discoverer of America
disembarked on the 3d of April, 1493, to present to the Catholic
monarchs the evidences of the happy termination of his enterprise. In
honoring Columbus they honor and exalt the sons of Catalonia, who also
took part in the discovery and civilization of the New World, among whom
may be named the Treasurer Santangel, Captain Margarit, Friar Benardo
Boyl, first patriarch of the Indies, and the twelve missionaries of
Monserrat, who accompanied the illustrious admiral on his second voyage.

In September, 1881, a national competition was opened by the central
executive committee for the monument, and by the unanimous voice of
the committee the premium plans of the architect, Don Cayetano
Buigas Monraba, were adopted. From these plans, which we find in _La
Ilustracion Española_, we give an engraving. Richness, grandeur, and
expression, worthily combined, are the characteristics of these plans.
The landing structure is divided into three parts, a central and two
laterals, each of which extends forward, after the manner of a cutwater,
in the form of the bow of a vessel of the fifteenth century, bringing to
mind the two caravels, the Pinta and Niña; two great lights occupy the
advance points on each side; a rich balustrade and four statues of
celebrated persons complete the magnificent frontage. A noble monument,
surmounted by a statue of the discoverer, is seen on the esplanade.

[Illustration: MONUMENTAL LANDING AND STATUE TO COLUMBUS, AT BARCELONA,
SPAIN.]

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The commission appointed in France to consider the phylloxera has not
awarded to anybody the prize of three hundred thousand francs that was
offered to the discoverer of a trustworthy remedy or preventive for the
fatal grape disease. There were not less than 182 competitors for the
prize; but none had made a discovery that filled the bill. It is said,
however, that a Strasbourg physician has found in naphthaline an
absolutely trustworthy remedy. This liquid is poured upon the ground
about the root of the vine, and it is said that it kills the parasites
without hurting the grape.

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SCENERY ON THE UTAH LINE OF THE DENVER AND RIO GRANDE.


Mr. R.W. Raymond gives the following interesting account of the
remarkable scenery on this recently opened route from Denver to Salt
Lake:

Having just made the trip from Salt Lake City to this place on the
Denver & Rio Grande line, I cannot write you on any other subject at
present. There is not in the world a railroad journey of thirty hours
so filled with grand and beautiful views. I should perhaps qualify this
statement by deducting the hours of darkness; yet this is really a
fortunate enhancement of the traveler's enjoyment; it seems providential
that there is one part of the way just long enough and uninteresting
enough to permit one to go to sleep without the fear of missing anything
sublime. Leaving Salt Lake City at noon, we sped through the fertile and
populous Jordan Valley, past the fresh and lovely Utah Lake, and up the
Valley of Spanish Fork. All the way the superb granite walls and summits
of the Wahsatch accompanied us on the east, while westward, across the
wide valley, were the blue outlines of the Oquirrh range. One after
another of the magnificent cañons of the Wahsatch we passed, their
mouths seeming mere gashes in the massive rock, but promising wild and
rugged variety to him who enters--a promise which I have abundantly
tested in other days. Parley's Cañon, the Big and Little Cottonwood, and
most wonderful of all, the cañon of the American Fork, form a series not
inferior to those of Boulder, Clear Creek, the Platte, and the Arkansas,
in the front range of the Rockies.

Following Spanish Fork eastward so far as it served our purpose, we
crossed the divide to the head waters of the South Fork of Price River,
a tributary of Green River. It was a regret to me, in choosing this
route, that I should miss the familiar and beloved scenery of Weber and
Echo cañons--the only part of the Union Pacific road which tempts one
to look out of a car window, unless one may be tempted by the boundless
monotony of the plains or the chance of a prairie dog. Great was my
satisfaction, therefore, to find that this part of the new road,
parallel with the Union Pacific, but a hundred miles farther south,
traverses the same belt of rocks, and exhibits them in forms not less
picturesque. Castle Cañon, on the South Fork of the Price, is the
equivalent of Echo Cañon, and is equal or superior in everything except
color. The brilliant red of the Echo cliffs is wanting. The towers
and walls of Castle Cañon are yellowish-gray. But their forms are
incomparably various and grotesque--in some instances sublime. The
valley of Green River at this point is a cheerless sage-brush desert,
as it is further north. To be sure, this uninviting stream, a couple of
hundred miles further south, having united with the Grande, and formed
the Rio Colorado, does indeed, by dint of burrowing deeper and deeper
into the sunless chasms, become at last sublime. But here it gives no
hint of its future somber glory. I remained awake till we had crossed
Green River, to make sure that no striking scenery should be missed by
sleep. But I got nothing for my pains except the moonlight on the muddy
water; and next time I shall go to bed comfortably, proving to the
conductor that I am a veteran and not a tender-foot.

In the morning, we breakfasted at Cimarron, having in the interval
passed the foot-hills of the Roan Mountains, crossed the Grande, and
ascended for some distance the Gunnison, a tributary of the Grande, the
Uncompahgre, a tributary of the Gunnison, and finally a branch, flowing
westward, of the Uncompahgre. A high divide at the head of the latter
was laboriously surmounted; and then, one of our two engines shooting
ahead and piloting us, we slid speedily down to Cimarron. It is in such
descents that the unaccustomed traveler usually feels alarmed. But the
experience of the Rio Grande Railroad people is, that derailment is
likely to occur on up-grades, and almost never in going down.

From this point, comparison with the Union Pacific line in the matter
of scenery ceases. As everybody knows, that road crosses the Rocky
Mountains proper in a pass so wide and of such gradual ascent that the
high summits are quite out of sight. If it were not for the monument to
the Ameses, there would be nothing to mark the highest point. For all
the wonderful scenery on the Rio Grande road, between Cimarron and
Pueblo, the Union Pacific in the same longitudes has nothing to show.
From an artistic stand-point, one road has crossed the ranges at the
most tame and uninteresting point that could be found, and the other at
the most picturesque.

At Cimarron, the road again strikes the Gunnison, and plunges into the
famous Black Cañon. In length, variety, and certain elements of beauty,
such as forest-ravines and waterfalls, this cañon surpasses the Royal
Gorge of the Arkansas. There is, however, one spot in the latter (I
mean, of course, the point where the turbulent river fills the whole
space between walls 2,800 ft. high, and the railroad is hung over it)
which is superior in desolate, overwhelming grandeur to anything on the
Gunnison. Take them all in all, it is difficult to say which is the
finer. I have usually found the opinion of travelers to favor the
Gunnison Cañon. But why need the question be solved at all? This one
matchless journey comprises them both; and he who was overwhelmed in the
morning by the one, holds his breath in the afternoon before the mighty
precipices of the other. To excuse myself from even hinting such folly
as a comparison of scenery, I will merely remark that these two cañons
are more capable of a comparison than different scenes usually are; for
they belong to the same type--deep cuts in crystalline rocks.

Between them come the Marshall Pass (nearly 11,000 ft. above sea-level),
over the continental divide, and the Poncha Pass, over the Sangre di
Cristo range. This range contains Harvard, Yale, Princeton, Elbert,
Massive (the peak opposite Leadville), and other summits exceeding the
altitude of 14,000 ft. To the east of it is the valley of the Arkansas,
into which and down which we pass, and so through the Royal Gorge to
Cañon City and Pueblo, where we arrived before dark on the day after
leaving Salt Lake.

Salt Lake, the Jordan Valley, Utah Lake, the Wahsatch, Castle Cañon, the
Black Cañon of the Gunnison, Marshall Pass, Poncha Pass, the Arkansas
Valley, the Royal Gorge--what a catalogue for so brief a journey! No
wonder everybody who has made it is "wild about it!" If enthusiastic
urgency of recommendation from every passenger has any influence (and I
know it has a great deal), this road will continue to be, as it is at
present, crowded with tourists. It furnishes a delightful route for
those who wish on the overland journey to see Denver (as who does not?)
and to visit Colorado Springs and Manitou. All this can be done _en
route_, without retracing the steps.

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PHOTOGRAPHY APPLIED TO TERRA-COTTA AND OPAL GLASS.


In the natural course of things it must necessarily have occurred to
practical men to utilize photography in the case of terra-cotta, as it
has already been employed in connection with so many other wares; but I
have not to this day known of its successful application to terra-cotta.
Now this is strange, if one considers how fashionable _plaque_ and plate
painting have become of late, and the good photographic results that
are easily obtained on these as on sundry articles of this same "burnt
earth." Portraits, animals, landscapes, seascapes, and reproductions are
one and all easily transferred, whether for painting upon or to be left
purely photographic. As a matter of business, too, one fails to see
that it would not be remunerative, but rather the contrary. It was with
something of this feeling that I was led to try and see what could be
done to attain the end in view, and as I knew of no data to go by, I had
to use my own experience, or rather experiment on my own account.

Since emulsion was constantly at hand in my establishment, in the
commercial production of my gelatine dry plates, it was but natural I
should first have turned to this as a mode of obtaining the desired
results; but, alas! all attempts in that direction signally failed--the
ware most persistently refused to have anything to do with emulsion. The
bugbear was the fixing agent or hypo., which not only left indelible
marks, but, despite any amount of washing, the image on a finished plate
vanished to nothing at the end of an hour's exposure in the show window.
There was nothing left but to seek other means for the attainment of my
object. I would not have troubled the reader as to this unsuccessful
line of experiment but that I wished to put him on his guard and save
him useless researches in the same direction. To cut matters short, the
method I found best and most direct was the now old but still excellent
wet collodion transfer. I will now proceed to detail my system of
working to facilitate the matter to the inexperienced in collodion
transfer.


TERRA-COTTA PHOTOGRAPHY IN PRACTICE.

The first and indispensable operation, in the preparation of the surface
to receive the transfer, is the "sizing of the surface." It simply
consists of a solution of gelatine chrome-alumed, as follows:

  Gelatine.                           10 grains.
  Water.                               1 ounce.
  A trace of chrome alum.

Coat with a soft camel's hair brush and let dry. It is needless to say
that numbers of _plaques_, plates, vases, etc., may be coated right off,
and will then be ready for use at any time.

Having settled on the subject and carefully dusted the negative, as well
as placed it _in situ_ for reproduction, the next thing required is a
suitable collodion, and the following will be found all that can be
desired:

  TRANSFER COLLODION.

  Cotton.                      3 drachms.
  Iodide of cadmium.          65 grains.
  Ammonium iodide.            25   "
  Bromide of cadmium.         19   "
  Ammonium bromide.           11   "
  Alcohol.                    15 ounces.
  Ether.                      15   "

The plate thoroughly cleaned and coated with the collodion is now
transferred to a bath, as follows:

Nitrate of silver (common) 25 grains to the ounce.

Made slightly acid with nitric acid.

After sensitizing, the plate is exposed in the usual way and taken to
the room where pictures are ordinarily developed, and _quantum suff_. of
the following poured into the developing cup to bring out the image:

  DEVELOPING SOLUTION.

  A Winchester of water, i.e.  80 ounces.
  Protosulphate of iron.      240 grains.
  Citric acid.                240   "

Or the following may be used:

  Pyro                          3 grains\
  Citric acid                   2   "    } per ounce of water.
  Glacial acetic acid          30 drops /

After perfect development the picture is well washed and then fixed in a
saturated solution of hypo.; after which it is thoroughly washed.

It will now be found that the picture is not altogether satisfactory; it
lacks both vigor and color. To improve matters recourse is now had to


TONING.

  Gold.    1 grain.
  Water.   5 ounces.

With this a very fine depth is soon attained, and a nice picture the
result. Leave out the toning, and only a poor, sunken-looking picture
will be the outcome; but directly the toning bath is employed richness
at once comes to the fore. I have, however, known of instances where the
picture needed no toning.


OPAL PRODUCTION IN PRACTICE.

This is still a secret with some in the profession. A limited number
of workers have succeeded in bringing out good opals, and their _modus
operandi_ is kept from the many. Now this is a pity, when one considers
the great charm attached to a good picture on opal, with pure whites and
rich blacks, and in many localities the demand that might be created for
them. Apart from their beauty, another charm attaches to opals--their
absolute permanence; and this, it must be allowed, is no trifle. What,
in fact, can be more painful to the worker who values his work, and sets
store by it, than to feel it must ere long fade and pass into oblivion!
A properly executed opal will no more fade than the glass pictures so
common at one time, and which, wherever taken care of, are as perfect
now as they were when first taken.

Now, excellent pictures are to be made on opals by means of emulsion;
but I propose first taking the transfer method (mainly applicable to
ground opal and canvas) as given above for pottery, since in practice
it is found very ready, easy of manipulation, and safe. The details are
much the same as above, and necessitate double transfer.

After the picture had been obtained on the plate (ordinary glass plate),
and after thoroughly fixing, washing, and toning, the picture (and this,
remember, is the case likewise with terra-cotta) then has to be loosened
from its support, and this is done with a solution of sulphuric
acid--one drachm to fifteen ounces of water--which is made to flow
between the image and the glass, after which perfectly wash and mount.
When the image is loosened a piece of tracing paper is put on the image,
evened out, raised (assisted by some one else to hold the two opposite
corners during the operation), and with the aid of the helper the
picture is carefully centered, gently pressed out or down, and the
transfer is so far effected. But what will happen, and does happen,
in the case of vignettes, is impurity of the whites, when the picture
becomes positively objectionable. Now the way to remedy this lies simply
in the application, to the dirty-looking parts, of a solution of iodine
dissolved in iodide of potassium to sherry color; after which, well wash
and apply a weak solution of cyanide of potassium, and wash well again.
This, by the way, is equally applicable to paper transfers; and it is
to be remembered that the toning comes last of all. It is a rather
difficult matter to clean a ground opal which has been used two or three
times, and acid must then be had recourse to (nitric acid is as good as
any); but by transferring from the support on the ground surface, all
stains are at once avoided.

On the flushed glass, or on the pot metal (unground), after well
cleaning the surface it should be covered with a substratum of egg. Then
the picture is taken direct, not transferred; that is, the plate is
exposed direct in the camera, regularly proceeded with, and, when dried,
varnished with a pale negative varnish, or with dead varnish if intended
for chalk or water-color. This, when a good negative is used, gives a
remarkably fine picture, not requiring a vestige of retouching, and
having likewise the invaluable advantage of being perfectly durable
if varnished with the negative varnish. Moreover, on that, effective
pictures may be made in oil with simply tinting.

A gentleman, who has a right to be considered a good judge in all art
matters, on looking at one of these pictures transferred on flushed
glass, said it was one of the finest productions of photography. He
urged that negatives _ad rem_ should be taken most carefully, and that,
like the picture I showed him, they should be full of half-tone and
detail, and yet have plenty of vigor. They should, he said, be robust in
the high lights, have perfectly clear glass in the few points of deep
shadows, and thus have powerful relief. Moreover, the negatives should
be retouched only by a competent hand, and care taken that the likeness
shall be in no way altered, which is so frequently the case now.

If done as thus suggested there is no doubt that remarkably fine
pictures are to be produced on opal, whether ground or not. Most
artistic results are to be obtained, and, with proper care, absolute
permanency. In this age of keen competition, all have to think of what
may be really recommended to one's _clientèle_, and likely to meet with
approbation from strangers and friends when the picture has once been
delivered; and I candidly think that the opal, of all, is the picture
most likely to meet with this general approbation.

I hope I have left it clearly to be understood that the class of opal
picture to which I have chiefly alluded is one that remains untouched
after the transfer--that is, absolutely unpainted upon. It is pure
photography in every sense of the word, and the resultant picture one
hardly to be surpassed in any way. I have rather laid a stress on this
point, well knowing how pictures are at times irretrievably ruined by
the barbarous hand of would-be artists, who by far exceed the true
artists in number; and the hint on retouching should not be lost sight
of, either, at a period when the tendency is to stereotype every one
in marble-like texture, or rather lack of texture, as if the face were
devoid of all fleshiness and as hard and rigid as cast-iron. It might
be wise to weigh this point carefully, and act upon it, before the
enlightened public have raised a cry against the pernicious practice
and made photographers smart for their want of applying timely remedial
measures to a decided evil.

On reading the above again, fearing lest any misconception should arise
in the mind of the reader, I deem it expedient, to clearly state that
for terra-cotta recourse is had to double transfer; that is, the picture
first taken is lifted from the support on tracing paper, put in
the right position on terra-cotta, and pressed down while wet with
blotting-paper, left to dry, and is then so far ready.

Respecting the production of pictures by means of emulsion, ground opal
being the best, the system I employ is as follows: After well cleaning
the glass, coat it with emulsion (which had better not be too thick).
When dry it is exposed and developed with the usual oxalate developer,
to which a little bromide of potassium has been added. The remainder of
the operations is as usual. Those varnished with dead varnish can be
tinted and worked up with colored crayons or black lead pencil and make
very pleasing pictures. It is needless to add that they are also to be
finished in water-colors if thought preferable.--_G. W. Martyn, in Br.
Jour. Photo_.

       *       *       *       *       *




PAPER NEGATIVES.


The process of A.C.A. Thiebaut is as follows: the paper has the
following advantages:

First. The sensitive coating is regular, and its thickness is uniform
throughout the entire surface of each sheet.

Second. It can be exposed for a luminous impression in any kind of slide
as usually constructed.

Third. It can be developed and fixed as easily as a negative on glass.

Fourth. The negative obtained dries quite flat on blotting paper.

Fifth. The film which constitutes the negative can be detached or peeled
from its support or backing easily and readily by the hand, without the
assistance of any dissolving or other agent. Thus this invention does
away with all sensitive preparations on glass, which latter is both a
brittle and relatively heavy material, thus diminishing the bulk and
weight of amateur and scientific photographers' luggage when traveling;
it produces photographic negatives as fine and as transparent as those
on glass, in so much that the film does not contain any grain; and,
lastly, it admits of printing from either face of the film, as regards
the production of positives on paper or other material, as well as
plates for phototypy and photo-engraving, which latter processes require
a negative to be reversed.

For the manufacture of my sensitized film paper:

First. A gelatinized sheet of paper is properly damped with cold water,
and when evenly saturated it is placed on a glass, to which it is
attached by means of bands of paper pasted partially on the glass, and
partially on the edges of the said sheet; in this state it is allowed to
dry, whereby it is stretched quite flat.

Secondly. I coat the dry sheet with a solution of ordinary collodion,
containing from one to two per cent. cubic measure of azotic cotton (1½
per cent. gives very good results) and from 1½ to 2½ per cent. of castor
oil (2 per cent. gives very good results); this coating is allowed to
dry; and,

Thirdly. The glass, with the prepared paper upward, is leveled, and then
it is coated, in a room from which all rays but red rays of light are
excluded, with a tepid emulsion of bromide of silver to the extent of
about one millimeter thick, and after leaving it in this position until
the gelatine has set (say) about five minutes, with the film paper still
attached, it is placed upright in a drying-room, where it should remain
about twelve hours exposed to a temperature of from 62 to 66 degrees
Fahrenheit; and,

Fourthly. The film paper is detached from the glass ready for exposure,
development, and fixing in the usual manner. For the purpose of
developing, oxalate of iron or pyrogallic acid answers equally well; for
the purpose of fixing, I have found that a mixture by weight, water,
1,000, hyposulphite of soda 150, and powdered alum 60, produces
excellent results, after being allowed to dry.

Fifthly. The film is peeled off the paper by hand, and can be
immediately used for producing negatives _recto_ or _verso_ as above
mentioned.

I claim as my invention:

First. The preparation or formation of gelatino-bromide film paper
for photographic negatives, in the manner and for the purposes above
described; and,

Secondly. The use for this purpose of castor oil, or any other analogous
oil, more especially with the view of peeling off the film from the
paper backing as above described.

       *       *       *       *       *




SOME OF THE USES OF COMMON ALUM.


A substance very much used by photographers of late years--in fact, so
much used that no well-appointed laboratory could be considered complete
without it--is the substance known is common alum, or potash alum, being
a double sulphate of alumina and potash; but it is interesting to note
that much of the commercial alum met with at the present time is ammonia
alum, or the double sulphate of alum and ammonia. It is quite a matter
of indifference to the photographer whether he uses potash alum or
ammonia alum.

Besides its great value to the autotype, Woodburytype, and mechanical
printers as an agent for hardening the gelatine films, it has been
recommended for all sorts of ailments photographic. The silver printer
adds a small portion to his sensitizing bath to keep it in working
order, and to prevent blistering of the albumen; then, again, silver
prints are soaked in a dilute solution of alum, having for its object
the thorough elimination of the last traces of the fixing salt. A very
good proportion to use for this latter purpose is four fluid ounces of a
saturated solution, diluted with one gallon of water, the prints being
well agitated during an immersion of ten minutes.

Of all the uses to which alum is put, perhaps not in any single instance
can so much satisfaction be derived as when it is used to
arrest frilling of gelatine plates. This it has the power to do
instantaneously, and many of the most careful workers, both amateur and
professional, or at least those who do net care to run any unnecessary
risks with negatives which have cost them a good deal of anxiety and
trouble to secure, but prefer to make assurance doubly sure--such
individuals may be numbered by the hundred--make it a point in every-day
practice to immerse all their plates in a solution of alum, either
before fixing, or immediately afterward. In fact, some operators have
two alum baths in use, one a normal bath, as above mentioned, for
immersing the plates in when of the ordinary printing intensity; and the
other a saturated solution strongly acidified by means of a vegetable
acid (such as citric) or a mineral acid (such as sulphuric), for use
when there is too much printing density, since it has been found
in practice that an acid solution of alum in contact with sodium
thio-sulphate on the gelatine image (after fixing, but before washing)
not only removes the color or stain caused by the alkaline or
pyrogallol, but perceptibly reduces the strength of the image. Moreover,
the color does not again reappear after washing, as it does sometimes
when the fixing salt has been partially washed away. In cases where
there is great tendency to frill--such, for instance, as when a soft
sample of gelatine has been employed, or old decomposed emulsion worked
in with the fresh emulsion--it will in such cases be safer to put the
plates in the normal-bath for a few minutes previous to immersing them
in the acid bath.

Potash alum is obtained tolerably pure in commerce in colorless
transparent crystalline masses, having an acid, sweetish, astringent
taste. It is soluble in 18 parts of water at 60° F., and in its own
weight of water at 212° F.; but the excess crystallizes out upon
cooling. The solution reddens litmus paper, and, when impure, usually
contains traces of oxide of iron. Upon the addition of either caustic
soda or potash, a white gelatinous precipitate is formed (hydrate of
alumina), which is soluble in excess of the reagent employed. The
precipitate thus obtained has much of the character of the opalescent
film sometimes observed on gelatine plates, when dry, which have been
soaked in alum, and not well washed afterward.

Alkaline carbonates--such as washing soda, for instance--precipitate
hydrate of alumina, which does not dissolve in an excess of the
reagents, and carbon dioxide is evolved.

Ammonia hydrate produces a precipitate in a much finer state of divison,
which does not dissolve in excess when examined in a test-tube, it
somewhat resembles thin starch paste.

The presence of traces of iron may be known by adding a few drops of
hydrochloric acid to a small quantity of a saturated solution of alum
in a test-tube, to which add strong liquid ammonia; should any iron be
present, the mixture will have a reddish-brown tinge when examined over
a sheet of white paper. Other alums exist, such as the double sulphate
of alumina and sodium, and sodium or aluminum and ammonium; but hitherto
their uses have been confined to the experimental portion of the
community rather than the practical.--_Photo. News_.

       *       *       *       *       *




CLOTH STRETCHING MACHINE.


As is well known, in the process of bleaching and dyeing, cotton cloths
become considerably contracted in the width, in consequence of carrying
on the operations when the cloth is in the form of a rope. The effect is
that, together with the tension, although slight, and the drying, the
weft partly shrinks and partly curls up, the latter, however, being
scarcely observable to the naked eye. It may almost be said that as
regards the width the shrinkage is due to a number of minute crumples
because the cloth is easily streatched again by the fingers almost to
its gray width. The main use of a stretching machine, therefore, is not
so much to make the cloth more than it is as to bring it again to its
normal or woven width after operations that tend to shrinkage have been
performed upon it. The stretching operation, therefore, is especially
useful to calico printers, as it enables them to obtain when desired a
white margin of even width, the irregularities due to bleaching being
corrected before printing.

[Illustration: IMPROVED CLOTH STRETCHING MACHINE.]

The machine now illustrated is one we have recently seen in operation in
a Salford finishing works. It is an improved form of another stretching
machine which had been turned out in considerable numbers by Mr.
Archibald Edmeston, engineer, of Salford, who makes a specialty of
calico printers' and finishers' machinery. The improvements consist
mainly of a simplification of the working parts and thoroughly
substantial construction of the machine. The principle adopted is a
well-known one. The selvages of the cloth, or more strictly the two
edges of the cloth, of a width of about two inches, are caused to pass
over and at the same time are held by the rims of two diverging pulleys.
The rims are further apart where the cloth leaves them than where they
seize it, hence the stretching is gradually, certainly, and uniformly
performed. The cloth is gripped by the pressure of an endless belt
acting against the lower half of each pulley, the edges being held
between them. In the engraving these stretching pulleys are indicated by
the letters AA; the endless leather band passes over the pulleys, CC, of
which there are a set of four provided for each stretching pulley. The
lower pair of pulleys in each case may be tightened up by a screw
for the purpose of imparting the requisite tension to the bands. The
stretching pulleys are mounted upon and driven by the same shaft, an
ingenious but simple swiveling joint in their bosses enabling them to
be set at any angle to the shaft and yet to revolve and be driven by it
without throwing any undue strain upon the working parts. The piece,
wound upon the ordinary batch shell, is placed upon the running-off
center, D; it is led off over the rails, EE, and then downward to the
nip of the bands and pulleys, AA. As explained, the selvages are here
gripped between the bands and stretching pulleys, the rims of which are
wider apart at the back than the front, and thus, in being conveyed
underneath, the piece is suitably stretched. Leaving the grip at the
back it passes over leading-off rollers, FF, and the scrimp or opening
rail, G, and thence downward to the winding-on center, which cannot be
seen. The winding-on center is driven by friction. As the batch fills
it and tends to wind faster than the machine delivers the cloth, the
driving slips. In addition to a capability of being set at an angle to
the shaft, the stretching pulleys, AA, may be slided upon, so as to
separate or bring them closer together, to allow for the treatment of
different widths of cloths. This adjustment is provided for by mounting
the stretching pulleys, AA, and the band pulleys, CC, etc., on frames,
BB, the ends of which rest, as shown, upon rails, at the back and front
of the machine. The adjustment either for width of piece or for the
angularity (extent of stretching) is easily made by the hand-wheel, L.
By the bevel wheels shown, two cross screws having nuts connected to the
ends of frames, BB, are actuated in such a way that as desired the space
between the back and front of the pulleys may be closed in or opened
out, or the two wheels, maintaining the same angularity, may be
separated or closed in, either adjustment being expeditiously made. The
wheels, HHH, are called center stretching wheels, the use of which is
sometimes advantageous. They act in conjunction with a set of stretching
pulleys, of which one, K, may be seen in illustration. By a proper
adjustment at the latter the piece is bent into a wavy form, where it
passes between the whole of them, the effect of the corrugation being
to loosen the center threads and to allow the piece to be more equally
stretched with those near the selvages and more easily. This part of the
machine may be used or not as required. The production, we observe, was
about 120 yards per minute. The machine is solidly built and well fitted
together, as was obvious to us from an inspection of some in course
of construction at the maker's works. It is also claimed to be of
considerable advantage to bleachers and finishers of white goods,
on account of the uniformity of the stretching causing but small
disturbance to the stiffening.--_Textile Manufacturer_.

       *       *       *       *       *




WOOLEN FABRICS PURIFIED BY HYDROCHLORIC ACID GAS.


All known methods for chemically purifying woolen stuffs from vegetable
fibers depend on the action of acids or substances of acid reaction.
The excessive temperature, hitherto unavoidable in the operation, acts
injuriously on the woolen fibers, especially during the formation of
hydrochloric acid, with which process especially the development of an
injuriously high temperature has been hitherto unavoidable. The best
method of absorbing the heat developed is in the evaporation of the
moisture naturally present in the wool. The patentees find agitation of
the fabric and the use of an exhauster during the process of material
assistance. The operation maybe successfully performed in two
ways--either by acting on the fabric at the ordinary pressure with
constant agitation, or by saturation without agitation in a vacuum. For
the first method the patentees employ a wooden cylinder with an aperture
at one end for inserting and removing the cloth, and having apertures
all round to allow free access of air. This cylinder rests on a hollow
axle, closed at one end and perforated with holes, through which the
acid gas is passed. By the rotation of the cylinder the gas is drawn
through the material and the latter exposed to the atmosphere, whereby
it gives up a quantity of aqueous vapor. An average temperature of 30°
Cent. is best suited to the operation, and it can be regulated according
to the supply of gas by opening or shutting a three-way cock between the
gas generator and the revolving cylinder. This process is assisted by
the use of an exhauster of the usual construction. When fully saturated,
the fabric is allowed to remain until the vegetable fibers are
sufficiently friable. The treatment _in vacuo_ is as follows:

The hydrochloric acid gas passes into a vessel of suitable material
provided with a perforated false bottom. From under this false bottom
a pipe connects with a second similar vessel connected itself with a
vacuum pump having a let-off pipe. As soon as the maximum vacuum is
attained, the gas is turned on through a three-way cock at a pressure of
40 mm. mercury. The gas fills the first vessel and saturates the cloth.
The warmth set free (about 500 calories per kilo, gas) is taken up
by the combined water in the wool, as, owing to the low pressure, a
quantity of vapor is formed sufficient to take up the heat. This vapor
streams through the second vessel at a temperature of 35° Cent.,
penetrates the material, and passes out through the pump. After
saturating the contents of the first vessel the gas passes into the
second. AS soon as this is one-quarter or one-third saturated the first
vessel is taken out and replaced by a third, which receives the overplus
from No. 2 in like manner, and so on. This plan of working prevents gas
passing through and damaging the pump. Instead of working under reduced
pressure, the desired low temperature can be maintained by passing
alternately with the gas currents of air which absorb heat in
evaporating the moisture of the material. The cloth, after saturation by
these processes, is left from six to twelve hours in the vessels, after
which it is freely exposed to the air until the vegetable particles
are friable. As soon as this occurs, the fabrics are washed. It is
advantageous to add to the wash water powdered carbonate of baryta,
strontia, magnesia, or preferably lime, and subsequently to rinse in
pure water. Phosphate of lime containing carbonate may also be employed
for neutralizing the acid, and the residue recovered and separated from
the organic residues mixed with it.--"_H. J.," Journal of the Society of
Chemical Industry._

       *       *       *       *       *




APPLICATION OF ELECTRICITY TO THE BLEACHING OF VEGETABLE TEXTILE
MATERIALS.


It is a recognized fact that chemical bodies in a nascent state are
characterized by peculiarly energetic affinities, and the results of
numerous experiments permit us to affirm that animal and vegetable
fibers are rapidly bleached when they are placed in contact with oxides
and chlorides which, when submitted to electrolysis, permit oxygen and
chlorine to disengage themselves in the nascent state.

The coloring matter that impregnates the majority of vegetable textile
substances, such as cotton, flax, and hemp, to cite only those most
generally known, is in fact completely destroyed only by the combined
action of oxygen and chlorine, which always act in the same manner,
whether the fibers be in a raw or woven state.

In the application of electrolysis to the bleaching of textile
materials, it is only necessary to have the electrodes of any
sufficiently powerful generator of electricity end in a vessel
containing in aqueous solution such decolorizing agents as the
hypochlorites in general, and chlorides, bromides, and iodides that are
capable of disengaging chlorine, and iodine or an iodide in a nascent
state. These gases perform the role of oxidizing or decolorizing agents.

The fibers that are immersed in the solution during the passage of the
electric current must necessarily remain therein for a greater or less
length of time, according to the nature of the material to be bleached,
and must, after this first operation, be washed, rinsed, and dried.

The use of an electric current for decomposing the metallic chlorides
and disengaging their elements is not new, and there have been specially
utilized for this purpose, up to the present time, the alkaline
hypochlorites that are obtained by well known processes.

In the latter case the metal is brought to the state of oxide in
presence of the water that is necessary for the reaction. But the
results obtained in practicing this method are deceiving, as far as
bleaching is concerned, and it is evidently more rational and economical
to endeavor to compound the hypochlorite directly by borrowing all its
elements from the metallic chloride itself, and from the water by means
of which such transformation is to be effected. This is a reversal of
the problem, and, _à propos_ thereof, we would call the attention of
the reader to an apparatus invented by Messrs. Naudin & Schneider for
effecting such synthesis in a simple and practical manner.

If a solution of chloride of sodium or kitchen salt, NaCl, be submitted
to electrolysis in a hermetically closed vessel containing the material
to be bleached, a formation of hypochlorite of soda is produced in the
following way:

2NaCl + 2 H_{2}O = NaCl + NaO, ClO + 4H.

In operating in this manner we shall have the advantage that results
from the nascent body through the electrical double decomposition of the
chloride of sodium and water, which puts the chlorine, the metal, the
hydrogen, and the oxygen simultaneously in presence. The chlorine and
oxygen will combine their action to decolorize the textile material.

While starting from this idea, it will nevertheless be preferable to
adopt Naudin & Schneider's arrangement.

The apparatus consists of a hermetically closed electrolyzer, A,
into the lower part of which enters the electrodes, E and F, of any
electrical machine whatever. The receptacle, A, is provided with a
safety-tube, T, that issues from its upper part and communicates with
a reservoir, B. A second tube, D, forms a communication between the
electrolyzer and the vessel, C. The liquid contained in this latter is
sucked up by a pump, P, and forced to the lower part of the vessel, A,
by means of the tubes, G and H.

The apparatus operates as follows:

The closed vessel, C, in which the material to be bleached is put, is
filled, as is also the electrolyzer, with a solution of chloride of
sodium. This solution is then submitted to the action of an electric
current, when, as a consequence of the chemical decomposition of
the chloride and the water, the elements in a nascent state form
hypochlorite of soda. When the partial or total conversion of the liquid
has been effected (this being ascertained by chlorometric tests), the
pump, P, is set rapidly in operation, and, as a consequence, draws up
the chloride of sodium from the bottom of the vessel, C, to the lower
part of the electrolyzer, A. The hypochlorite that has formed passes
through the tube, D (as a natural consequence of the elevation of the
level of the liquid in A brought about by the entrance of a new supply
of chloride), and distributes itself throughout the vessel, C, where it
acts upon the textile material.

[Illustration: APPARATUS FOR BLEACHING TEXTILE FIBERS BY ELECTRICITY.]

The safety-tube, T, which is attached to the electrolyzer, permits
of the escape of the hydrogen which is produced during the chemical
reaction, and fixes, through an alkaline solution contained in the
reservoir, B, the chloride whose escape might discommode the operator.

As may be conceived, the slow transfer of the saline solution from
the receptacle, C, to the electrolyzer, and its rapid conversion into
decolorizing chloride, as well as its prompt application upon the
materials to be bleached, presents important advantages.

While, in the present state of the industries that make use of bleaching
chlorides, the chloride of sodium is converted into hydrochloric acid,
which, in order to disengage chlorine, must in its turn react upon
binoxide of manganese, we shall be able, with this new method, to
utilize the chloride of sodium, which is derived from ordinary salt
works, and extract from it the constituent elements of the hypochlorite
by a simple displacement of molecules produced under the influence of an
electric current.

Another and very serious advantage of electric bleaching is that of
having constantly at hand a fresh solution of hypochlorite possessing a
uniform decolorizing power, which may be regulated by the always known
intensity of the current.

We must remark that the hypochlorites require a certain length of time
to permit the chlorine to become disengaged, and that, besides, all
chlorides, bromides, and iodides that are isomorphous are capable of
undergoing an analogous chemical transformation and of being employed
for the same purpose. This is especially the case with the chlorides
of potassium or barium, the bromides of strontium or calcium, and the
iodides of aluminum or magnesium. On another hand, as sea water contains
different chlorides, it results that it might serve directly as a raw
material for bleaching textile fibers. Then, when the solution of
chloride of sodium has been deprived of its chlorine by electrolysis,
there remains a solution of caustic soda which may be utilized for
scouring fibers.--_H. Danzer, in Le Génie Civil_.

       *       *       *       *       *




IMPROVED SPRING TRACTION ENGINE.


Messrs. J. & H. McLaren, of the Midland Engine Works, Hunslet, Leeds,
England, for several years past have devoted considerable attention to
the question of mounting traction engines on springs. The outcome of
this is the engine in question, the front end of which is carried by a
pair of Timmis spiral springs, resting on the center pin of the front
axle, which is on Messrs. McLaren's principle, which enables it to
accommodate itself to the inequalities of the road without throwing any
undue strain on the front carriage. The chief difficulty hitherto has
been to mount the hind end on springs without interfering with the spur
gearing, which must be kept perfectly rigid to prevent breakage of the
cogs. This is entirely provided for by the new arrangement, whereby all
the spring is allowed for in the spokes of the wheel itself, which will
be clearly seen on reference to the illustrations, in which Fig. 1 is a
perspective view of the engine, while Fig. 2 shows a detail view of the
wheel. The rim of the wheel is built up in the ordinary way of strong
T-iron rings, with steel crossplates riveted on. The nave of the wheel
has wrought-iron ribs to which the spokes are bolted. These spokes are
made of the best spring steel, specially manufactured and rolled for the
purpose, 9 inches wide and ½ inch thick. They are bent in a pear shape,
with the narrow ends fastened to the nave, and the crown resting upon
the rim of the wheel, where they are divided, and held in their places
by means of clip fastened with bolts. When the weight of the engine
comes on these spokes, those nearest the ground are compressed and
those, at the top are elongated a little. In order to avoid any of the
driving strain passing through the springs, a strong arm is fixed on the
differential wheel and attached to the rim as shown in Fig. 2, so that
the springs have really no work to do beyond carrying the weight of the
engine. Messrs. McLaren naturally felt a certain amount of diffidence
in placing their invention before the public until they had thoroughly
tested it in practical work. This, we are informed, they have done, with
the most satisfactory results, during the last five or six months; and
they have a set of springs which ran during that time between 2,000 and
3,000 miles, besides which there are several of these spring engines in
daily use.--_Iron_.

[Illustration: FIG 1. IMPROVED SPRING TRACTION ENGINE.]

[Illustration: FIG. 2]

       *       *       *       *       *




TABLE SHOWING THE RELATIVE DIMENSIONS, LENGTHS, RESISTANCES, AND WEIGHTS
OF PURE COPPER WIRE.


         DIAMETER    |         AREA
                     |
B.W.G  Inch. Milli-  | Circu-  Square      Square
No.          metres  | lar     inches.     Milli-
                     | Mils.               metres.
                     |
0000   .454  11.5313 | 206116  .161883     10.4435
 000   .425  10.795  | 180625  .141862      9.152
  00   .38    9.6518 | 144400  .113411      7.3165
   0   .34    8.6358 | 115600  .0907922     5.8573
   1   .3     7.620  |  90000  .070686      4.5602
   2   .284   7.2134 |  80656  .0633472     4.0867
   3   .259   6.5784 |  67081  .0526854     3.3989
   4   .238   6.0451 |  56644  .0444881     2.8701
   5   .22    5.5879 |  48400  .0380133     2.4523
   6   .203   5.1561 |  41209  .0323655     2.088
   7   .18    4.5719 |  32400  .0254469     1.6417
   8   .165   4.1909 |  27225  .0213825     1.3794
   9   .148   3.7591 |  21904  .0172034     1.1098
  10   .134   3.4035 |  17956  .0141026      .9096
  11   .12    3.0479 |  14400  .0113097      .7296
  12   .109   2.7701 |  11881  .00933133     .60199
  13   .095   2.4129 |   9025  .0070882      .4573
  14   .083   2.1082 |   6889  .00541062     .34906
  15   .072   1.8288 |   5184  .00407151     .2486
  16   .065   1.6510 |   4225  .00331831     .21407
  17   .058   1.4732 |   3364  .0026421      .17045
  18   .049   1.2446 |   2401  .00188574     .12165
  19   .042   1.0668 |   1764  .00138544     .0894
  20   .035   0.8890 |   1225  .000962115    .06207
  21   .032   0.8128 |   1024  .00080425     .05188
  22   .028   0.7112 |    784  .000615753    .03972
  23   .025   0.635  |    625  .00049087     .03167
  24   .022   0.5588 |    484  .000380133    .02452
  25   .02    0.508  |    400  .00031416     .02027

  26   .018   0.4571 |    324  .000254469    .01642
  27   .016   0.4064 |    256  .000201062    .01297
  28   .014   0.3556 |    196  .000153938    .00993
  29   .013   0.3302 |    169  .000132732    .00856
  30   .012   0.3048 |    144  .000113097    .007296

LENGTH AND WEIGHT

B.W.G  Pounds      Pounds       Pounds      Pounds      Feet       Yards        1.000 feet  Miles
No.    per         per          per 1.000   per         per lb.    per lb.      per lb.     per lb.
       foot.       Yard         ft.         mile.

0000   .623924     1.871772     623.924     3294.32       1.60276     .534253    .00160276  .00303553
 000   .54676      1.64028      546.76      2886.89       1.82895     .60965     .00182895  .0034639
  00   .437105     1.311315     437.105     2307.92       2.28777     .76259     .00228777  .004333
   0   .349928     1.049784     349.928     1847.62       2.85773     .9525766   .00285773  .0054124
   1   .272435      .817305     272.435     1438.43       3.6706     1.22353     .0036706   .0069519
   2   .244151      .732453     244.151     1289.11       4.0958     1.365266    .0040958   .0077573
   3   .203058      .609174     203.058     1072.15       4.9247     1.641566    .0049247   .009327
   4   .171463      .514395     171.465      905.333      5.8321     1.944033    .0058321   .0110457
   5   .14651       .43953      146.510      773.56       6.8255     2.275166    .0068255   .012927
   6   .124742      .374226     124.742      658.638      8.0165     2.672166    .0080165   .015183
   7   .098076      .294228      98.076      517.844     10.1962     3.39873     .0101962   .019311
   8   .082411      .247233      82.411      435.135     12.1345     4.04483     .0121345   .022981
   9   .066305      .198915      66.305      350.089     15.0818     5.027266    .0150818   .028564
  10   .054354      .163062      54.354      286.99      18.398      6.13266     .018398    .034845
  11   .04359       .13077       43.590      230.152     22.9413     7.6471      .0229413   .04345
  12   .035964      .107892      35.964      189.893     27.805      9.2683      .027805    .05266
  13   .027319      .081957      27.319      144.245     36.6046    12.20153     .0366046   .069326
  14   .020853      .062559      20.853      110.1088    47.954     15.98466     .047954    .09082
  15   .015692      .047076      15.692       82.855     63.7267    21.24223     .0637261   .12069
  16   .012789      .038367      12.789       67.5276    78.1902    26.0634      .0781902   .14809
  17   .0101828     .0305484     10.1828      53.7665    98.202     32.734       .098203    .18589
  18   .00726795    .02180388     7.26796     38.3748    137.590    45.8633      .137590    .260587
  19   .00533972    .01601916     5.33972     28.1937    187.276    62.4253      .187276    .35469
  20   .00370815    .01112445     3.70815     19.579     269.676    89.892       .2696676   .51075
  21   .00309972    .00929910     3.09972     16.3665    322.610   107.5366      .322610    .61100
  22   .00237312    .00711936     2.37312     12.5301    421.384   140.4613      .421334    .798078
  23   .0018910     .0056757      1.8919       9.9892    528.570   176.190       .528570    .100108
  24   .0014650     .0043950      1.4650       7.7357    682.55    227.5166      .68255     .129271
  25   .00121082    .00363246     1.21082      6.39315   825.880   275.2943      .825883    .156417
  26   .00098077    .00294231      .98077      5.17844  1019.61    339.870      1.01961     .193108
  27   .00077492    .00232476      .77492      4.0916   1290.44    430.1466     1.29044     .24440
  28   .0005933     .0017799       .5933       3.13264  1685.48    561.8266     1.68548     .31922
  29   .000511571   .001534713     .511571     2.7011   1954.76    651.5866     1.95476     .370220
  30   .0004359     .0013077       .4359       2.30152  2294.13    764.710      2.29413     .434496

LENGTH AND RESISTANCE

B.W.G  Feet         Yards        1.000 feet   Miles      Ohms         Ohms          Ohms        Ohms
No.    per Ohm.     per Ohm.     per Ohm.     per Ohm.   per foot.    per yard.     per 1.000   per mile.
                                                                                    foot.

0000   19966.5      6655.5       19.9665      3.7815     .000050684   .00156252       .050084      .264443
 000   17497.15     5832.3833    17.49715     3.31385    .0000571522  .0001714566     .0571522     .301763
  00   13988.64     4662.68      13.98804     2.64925    .000071489   .000214467      .071489      .377465
   0   11198.17     3732.7333    11.19817     2.12086    .0000893002  .0002679006     .0893002     .471505
   1    8718.30     2906.10       8.71830     1.6512     .00011470    .0003441        .114701      .60562
   2    7813.50     2604.50       7.81350     1.47973    .00012799    .00038397       .12799       .67580
   3    6498.14     2166.0466     6.49814     1.23071    .00015389    .00046167       .15389       .81254
   4    5487.107    1829.0357     5.487107    1.03923    .000182245   .000546735      .182245      .962256
   5    4688.51     1562.8366     4.68851      .887975   .000213287   .000639861      .213287     1.12616
   6    3991.91     1330.6366     3.99191      .756045   .000250506   .000751518      .250506     1.32267
   7    3138.59     1046.1966     3.13859      .59443    .000318614   .000955842      .318614     1.68228
   8    2637.29      879.0966     2.63729      .499486   .000379177   .001137531      .379177     2.00206
   9    2121.84      707.280      2.12184      .401864   .000471289   .001413867      .471289     2.488405
  10    1739.40      579.80       1.73940      .329432   .000574911   .001724733      .574911     3.03553
  11    1394.93      464.9766     1.39493      .264191   .000716882   .002150646      .716882     3.78514
  12    1150.91      383.6366     1.15091      .217976   .000868875   .002606625      .868875     4.58766
  13     874.252     291.4173      .874252     .165578   .00114383    .00343149       1.14383     6.03945
  14     667.338     222.446       .667338     .12639    .00149849    .00449547       1.49849     7.91203
  15     502.175     167.39166     .502175     .095109   .00199134    .00597402       1.99134    10.5142
  16     409.276     136.42533     .409276     .077514   .00244334    .00733002       2.44334    12.9008
  17     325.871     108.62366     .325871     .061718   .0030687     .0092061        3.0687     16.20274
  18     232.585      77.52833     .232585     .04405    .0042995     .0128985        4.2995     22.7014
  19     170.879      56.95966     .170879     .032363   .0058521     .0175563        5.8521     30.8991
  20     149.3915     49.797166    .1493915    .022475   .00842703    .02528109       8.42703    44.4947
  21      99.195      33.065       .099195     .018787   .01008110    .03024348      10.08116    53.2285
  22      75.9461     25.315366    .0759461    .014384   .0131672     .0395016       13.1672     69.5230
  23      60.54377    20.181256    .06054377   .011467   .0165170     .0495510       16.5170     87.2096
  24      46.8851     15.628356    .0468851    .0088798  .02132874    .06398622      21.32874   112.616
  25      38.748      12.916       .038748     .0073386  .025808      .077424        25.808     136.265
  26      31.3859     10.461966    .0313859    .0059443  .03186144    .09558432      31.86144   168.229
  27      24.79873     8.266243    .02479873   .0046967  .0403246     .1209738       40.3246    212.914
  28      18.98653     6.328843    .01898653   .0035959  .05266892    .15800676      52.66892   278.092
  29      16.3710      5.4570      .0163710    .0031006  .0610834     .1832502       61.0834    322.521
  30      13.9493      4.649766    .0139493    .0026419  .07168825    .21506475      71.68825   378.514

RESISTANCE & WEIGHT

B.W.G  Ohms           Lbs.
No.    per lb.        per Ohm.

0000      .000080272  12457.5
 000      .000104529   9566.7
  00      .000163553   6114.24
   0      .000255196   3918.58
   1      .00042102    2375.18
   2      .00052422    1907.59
   3      .00075786    1319.50
   4      .0010629      940.844
   5      .0014558      686.911
   6      .0020082      497.96
   7      .00324863     307.822
   8      .00460101     217.343
   9      .00710791     140.689
  10      .0105772       94.543
  11      .0164462       60.842
  12      .0241593       41.392
  13      .0418692       23.8839
  14      .0718583       13.9163
  15      .126788         7.8872
  16      .191045         5.2344
  17      .301355         3.31835
  18      .59157          1.6904
  19     1.09596           .912445
  20     2.27254           .44003
  21     3.25229           .30748
  22     5.54843           .18023
  23     8.73035           .11454
  24    14.5579            .068691
  25    21.3142            .046917
  26    32.4863            .030782
  27    52.0367            .019217
  28    88.7724            .011265
  29   119.404             .008375
  30   164.4762            .0060804

PURE COPPER weighs 555 lbs. per cubic foot. The Resistance of 1 mil.
foot at 60° Fahr. is, according to Dr. Matthiessen, 10.32311 ohms. Upon
these data the above Table has been calculated.

The _Resistance_ of Copper varies with the temperature about 0.38 per
cent. per degree Centigrade, or 0.21 per cent. per degree Fahrenheit.

STRANDED WIRES.--With a conductor of a definite lenght, made of
_Stranded_ Wires, the total _weight_ is _greater_, and the _Resistance
less_ than is a similar length of Conductor with Wires _not_ Stranded.

  To convert--Inches to Millimetres multiply by 25.3994
              Feet to Metres            "         .3048
              Yards to Metres           "         .9144
              Miles to Kilometres       "         .6214
              Pounds to Kilogrammes     "         .45359

PEPARED BY WALTER T. GLOVER & CO., ELECTRICAL WIRE AND CABLE MAKERS, 25,
BOOTH STREET MANCHESTER.

       *       *       *       *       *




IRON FRAME GANG MILLS.


The gang mill is regarded as possessing material advantages in the rapid
and economical manufacture of lumber. Among the recent improvements
tending to perfect such mills, those which are shown in the iron frame
stock gang, manufactured by Wickes Bros., East Saginaw, Mich., are
eminently valuable. Our large engraving represents one of these mills,
constructed to be driven by belt, friction, or direct engine, as may be
desired. The important requisite in this class of mills is such design
and proportion of parts as will insure durability and continued movement
at the highest speed, safely increasing the quantity and improving the
quality of work done at a lesser feed, and admitting the use of thinner
saws than is practical in the slower moving sash. These are among the
advantages gained in the iron frame machine, overcoming the necessity
of an expensive mill frame, saving time and expense in setting up, and
avoiding the liability of decay or change of position.

[Illustration: IMPROVED IRON FRAME GANG SAW MILL.]

Many improvements have been made in the mechanism of oscillation, and
from these the builders of this mill have adopted what is known as the
Wilkin movement, which oscillates the top and bottom slides. The top
slides are pivoted at the top end, and the bottom ones from the bottom
end, both being operated by one rock shaft from the center. This
movement when properly adjusted gives an easy clearance and the easiest
cut yet obtained. It adds no extra weight to the sash, and avoids the
cumbrous rock shaft and its attendant joints, usually weighing from
three hundred to five hundred pounds, which have been found so
objectionable in many other movements. The feed is continuous, and is
made variable from ¼ to 1¼ inch to each stroke, controllable by the
sawyer. Power is applied to the press rolls in the double screw form
with pivot point, also operated by the same hand. A special feature of
this machine is the spreading of the lower frame so that its base rests
upon an independent portion of the foundation from the main pillow block
or crank shaft. The solidity of the whole structure is thus increased,
both by the increased width at the base and the prevention of connecting
vibrations, which necessarily communicate when resting upon the same
part, as in other forms of such machines heretofore in use.

The mill shown in the perspective view is one of twenty-six saws 4½ feet
long, sash 38 inches wide in the clear, and stroke 20 inches, capable
of making 230 strokes per minute. The crank shaft is nine inches in
diameter, of the best forged iron. The main pillow block has a base
6½ feet long by 21 inches bearing, weighing 2,800 pounds. The cap
is secured by two forged bolts 3½ inches in diameter, and by this
arrangement no unequal strain upon the cap is possible. A disk crank is
used with suitable counterbalance, expressly adapted to the weight and
speed of sash; a hammered steel wrist pin five inches in diameter, and a
forged pitman of the most approved pattern, with best composition boxes.
The iron drive pulley is 4 to 4½ feet in diameter and 24 inches face;
the fly-wheel six feet in diameter, and weighing 4,700 pounds, turned
off at rim. When a wider and heavier sash is required, a proportionate
increase is made in all these parts.

In the construction of the sash the stiles are made of steel; the lower
girt and upper heads are made in one solid piece, without rivets, giving
the greatest strength possible, with the least weight. The outfit also
includes eight iron rollers for the floor, 8½ inches in diameter, with
iron stands, and geared as live rolls when desired, a full set of
Lippencott's steel saw hangings, and gauges for one-inch lumber. The
weight of the machine here shown is 18½ tons. They are, however, built
in larger or smaller sizes, adapted to any locality, quality or quantity
of work desired.

       *       *       *       *       *

It is said that the St. Gothard Tunnel is diverting the bulk of the
Italian trade into the hands of the Belgians, Germans, and Hollanders
with startling rapidity. Without breaking bulk, early fruits are taken
from all parts of Italy to Ostend, Antwerp, and Rotterdam, whence they
are carried by fast steamers to London and other English ports. But, on
the other hand, Germany is sending into Italy large quantities of coal,
iron, machinery, copper, and other articles of which the latter received
nothing before. In two months alone, the Italians imported 1,446 tons of
paper.

       *       *       *       *       *




THE HEAT REGENERATIVE SYSTEM OF FIRING GAS RETORTS.


The system of heat regeneration in the firing of gas retorts, in
accordance with the principle which Dr. C.W. Siemens has worked out in
such a variety of ways in the industrial arts, has lately been applied
with very marked success at the Dalmarnock Station of the Glasgow
Corporation Gas Works. Notwithstanding the fact that a period of about
twenty years has elapsed since Dr. Siemens successfully adapted his
system to the firing of retorts at the Paris Gas Works, it seems to have
made but little progress up to the present time; for what reasons it is
perhaps difficult to explain. It is certain, however, that so-called
regenerator furnaces of various forms have, from time to time, been
brought into use at gas works for the purpose in question both on the
Continent and in this country; and in recent years the subject has
received much attention from gas engineers, the general opinion
eventually being that the adoption of such a system of working would be
certain to result in so great an amount of economy as to put gas as an
illuminating agent on a more secure footing to compete successfully with
its modern and somewhat aggressive rival, the electric light. Of course,
it is now admitted that the mode of adapting the heat regenerative
principle at the Paris Gas Works was attended with a degree of
complexity in the structural arrangements that was so great and so
expensive as to place it practically beyond the reach of gas companies
and gas corporations generally, when the expense as well as the
scientific beauty and practical efficiency of the new mode of applying
and utilizing heat had to be considered. Fortunately, however, Dr.
Siemens was enabled two or three years ago to demonstrate that there was
no such thing as "finality" in that department of invention which he had
made almost exclusively his own. About the time mentioned he placed
his most advanced views on gas producers and on the regeneration and
utilization of heat before the world, and within that period a most
decided step in advance has been made, the structural arrangements
now required for gas producers and regenerator furnaces having been
immensely simplified and cheapened, while their practical utility has in
no way been interfered with.

Scarcely had Dr. Siemens announced his new form of gas producer and
regenerator than communication was opened with him by Mr. W. Foulis, the
general manager to the Glasgow Corporation Gas Trust, with the view of
entering into arrangements for its adoption on an experimental scale
at one of the stations under his charge. Encouraged by the hearty
co-operation of the gas committee, two or three of whose members were
well known engineers, Mr. Foulis very soon came to an understanding with
Dr. Siemens to have the regenerative system put to a thorough test at
the Dalmarnock Gas Works, situated in the extreme east end of the city,
and the largest establishment of the kind in Scotland, the total number
of retorts erected being about 750. The system in its most recent shape
was applied to four ovens, each of which had seven retorts, but which
number has since been increased to eight, owing to the space occupied
by the furnace in the ordinary settings being rendered available for
an additional retort in the new or "Siemens" setting. For each oven or
chamber of eight retorts there was erected a separate gas-producer,
so that even one set of eight retorts might alone be used if thought
necessary.

[Illustration: GAS RETORTS WITH REGENERATIVE FURNACES .--GLASGOW
CORPORATION GAS WORKS.]

In Figs. 1 and 2 of our illustrations, the general arrangement and the
relationship of the gas producer, the regenerators, and the retorts to
each other are clearly shown. It was a sort of _sine qua non_ of the new
method of firing the retorts that the producer should be in as close
proximity as possible to the place where the gaseous fuel was to be
used, and it was concluded that the most convenient situation would be
immediately in front of its own set of eight retorts, and with its top
on a level with the working floor of the retort house. To place it
in such a position meant a good deal of excavation, which was also
required, however, for the regenerator flues. The excavation was carried
down to a depth of 10 ft. below the level of the retort house floor, and
as a matter of course the operation of underpinning had to be resorted
to for the purpose of carrying down the foundations of the division
walls, which, together with the main arches and the hydraulic main, were
in no way otherwise disturbed. As in most new inventions, a good deal
of difficulty was experienced at first in connection with these gas
producers and heat regenerator furnaces; but by dint of application and
by the adoption of modifications made here and there in the arrangements
from time to time, as also by a determination not to be beaten, although
often disheartened, Mr. Foulis was ultimately rewarded with complete
success. The new system of firing being made so simple that there was
scarcely any possibility of failure likely to arise in ordinary practice
if it was superintended with but a moderate amount of care.

[Illustration: _Fig. 3._]

The results which were obtained in course of time with four ovens, or a
total of 32 retorts, were so exceedingly promising that it was forthwith
resolved to extend the new mode of firing to the whole of a double bench
of twelve ovens, now containing 96 retorts; and all the improvements
which had suggested themselves during the working experiments with the
four ovens were adopted from the first in the reconstruction of the
remaining eight ovens in the bench. More recently the regenerator system
has been applied to other 22 ovens, or 176 additional retorts, being the
whole of one of the main divisions of the retort house; and during the
very depth of the present winter, when the demand for gas was at its
greatest height, all the retorts of the converted or "Siemens" settings,
amounting to 272, were in full working activity, in which condition they
still remain. It is intended to make another very considerable extension
of the heat regenerative system of firing during the ensuing spring and
summer. The reconstruction of the present year will extend to the ovens
of seven retorts each, giving in this case eighty gas fired retorts; and
to twenty ovens of five retorts each, which will become sixteen ovens,
each having eight retorts, making 128 retorts in this division, and the
total being 208 retorts in place of 170 in the same amount of space. It
is confidently anticipated, therefore, that by the month of August of
the present year, 480 full sized retorts will be available for working
out the new method at the Dalmarnock Gas Works. Furthermore, the
confidence which has been inspired in the minds of the members of the
Glasgow Corporation Gas Committee and their engineer regarding the
actualities and possibilities of the Siemens system of firing gas
retorts, in its most improved state, is such that arrangements are
being made for starting shortly to apply it throughout at the Dawsholm
Station, which is situated in the suburban burgh of Maryhill, and some
four or five miles distant from the Dalmarnock Works in a northwestern
direction. The station just named, which is also a very large one, will
probably require two years for its conversion.

We shall now give some account of the structural arrangements adopted
for producing cheap gaseous fuel, and for turning that fuel to the
greatest advantage in firing the retorts for the purpose of carbonizing
the cannel coal used as the source of the gas.

The gas producer, which is represented in vertical section in Fig. 2, is
a cylinder of brickwork inclosed in a casing of malleable iron. It is 7
ft. 6 in. deep, and 3 ft. in diameter, which becomes reduced to 20
in. above, where it is closed by means of a cast-iron lid, which is
continuous with the floor of the retort house. There are no firebars
at the bottom, so that the fuel rests on a floor of firebrick. At the
bottom of the walls of the producer there are several holes about 1 ft.
in length by 6 in. in height. By means of these openings any clinker
that may form and the ashes of the spent fuel can readily be withdrawn.
They also allow of the admission of air to maintain the combustion in
the lower portion of the mass of fuel; and at each opening there is a
malleable iron tube for delivering a jet of steam direct from a steam
boiler. We shall subsequently explain the functions performed by the
steam.

The fuel employed is the coke or char resulting from cannel coal when it
has yielded up its hydrocarbons and other gases during the process of
carbonization in the gas retorts. Being entirely made from Scotch cannel
the coke is very poor in quality, as it contains a large percentage of
mineral matter or ash relatively to its fixed carbon. The retorts are
worked with three-hour charges, but the producer is only charged once in
every six hours For each set of eight retorts the charge of raw cannel
is about 18 cwt., and it is found in practice that the coke drawn from
five of the retorts is quite sufficient to fill up the producer to the
top. Formerly a set of seven retorts fired in the ordinary way from a
furnace underneath, required from 60 to 75 per cent. of the coke made,
but now, with eight retorts in each oven, the quantity has been reduced
to about 30 per cent., or less than one-half of what it formerly was.
Before the retorts are drawn the lid is removed from the top of the
producer, and any fuel still remaining unconsumed is touched up a bit by
way of leveling it on the surface, and as soon as it has been filled up
to the constricted portion a shovelful of soft luting is spread over the
top of the coke, and the lid is laid upon it and driven home, thereby
making a perfectly air-tight joint. The contents of the other three
retorts, as also the contents of the whole of the retorts at each
alternate drawing, are taken to the coke heap in the yard. We have
already spoken of a charge of cannel as being about 18 cwt. for each set
of eight retorts, but in connection with that matter we should mention
that it was formerly about 13 cwt. per oven containing seven retorts,
and that there is every prospect of it being increased without
increasing the length of time occupied in carbonizing the cannel of each
charge.

It may be worth while now to notice briefly what takes place among the
mass of coke in the gas producer. The atmospheric air admitted at the
several openings previously spoken of ascends through the lower layers
of the incandescent coke, the carbon of which burns to carbonic acid
gas at the expense of the oxygen of the air. Among the middle and upper
layers of the incandescent coke the carbonic acid gas takes up a further
quantity of the fixed carbon, and becomes transformed into carbonic
oxide gas (CO_{2}+C=2CO), which is an inflammable body, and possesses
considerable calorific power. Unless the carbonic acid gas is very
completely "baffled" in its ascent through the coke in the producer, a
quantity of it passes into the furnace along with the carbonic oxide,
the efficiency of which is diminished in proportion as the former
increases in quantity. Of course, also, the nitrogen associated with
the oxygen in the air admitted to the gas generator passes on with the
carbonic oxide gas, this nitrogen acting as a dilutant and being of
course absolutely useless as a generator of heat. The steam which
we previously spoke of serves two good purposes. In contact with
incandescent coke it suffers decomposition, its oxygen uniting with some
of the fixed carbon to form carbonic oxide, while the hydrogen which
is set free passes onward, and mixes with the other gases to be
subsequently consumed with them. The admission of the steam thus causes
the absorption of heat in the gas generator where the decomposition
takes place, this heat being again evolved on the subsequent combustion
of the hydrogen. Then, again, as the steam is delivered in among the
coke in a jet, or a series of jets, it has the effect of almost entirely
preventing any clinkering or slagging of the earthy and silicious
materials, which form such a large portion of the substance of the coke
obtained from Scotch cannels, sometimes as much as from 15 to 20 per
cent. It is scarcely necessary for the stokers to go down below to the
bottom of the producers to remove the ash above once in every six hours.
Referring to the composition of the gaseous fuel obtained from cannel
coke in one of these gas producers, we give the following typical
analysis on the authority of Dr. William Wallace, F.R.S.E., gas
examiner, and one of the public analysts for the city of Glasgow:

                     Per cent.
  Hydrogen             8.7
  Carbonic oxide      28.1
  Carbonic acid        3.5
  Oxygen               0.4
  Nitrogen            59.3
                     -----
                     100.0

By again referring to Fig. 2, it will be observed that an opening is
provided for the passage of the gaseous matter as it is formed into the
mass of brickwork, the upper half of which is occupied by the retorts of
the setting and the lower by the regenerators.

Before following the gas we may first direct attention to the
arrangements for dealing with it, and with the air that has to be
admitted for the combustion of so much of it as is of a combustible
nature. It will be seen by reference to Fig. 1 that the oven proper is
occupied by eight [Inline Illustration] shaped retorts. These are 9 ft.
long (set back to back) by 18 in. by 13 in., and they are placed on
arches which are 8 ft. 6 in. wide. Underneath the level of the retort
oven there are two regenerators or regenerator chambers, which differ
very materially in form from the regenerators formerly applied by Dr.
Siemens to gas retort ovens, and which are still employed for high
temperature furnaces like those used for steel and glass melting. In
the case of these latter the regenerators are on the alternating
system--that is to say, a mass of brickwork is heated by the waste heat
of the effluent gases, and when that is made sufficiently hot, the
current of waste gases is turned into a second mass of brickwork, while
air is admitted to pass through the brickwork already heated. The system
thus briefly described entails a certain amount of attention on the part
of the workmen in the altering of the valves or dampers to reverse the
currents. The regenerator now adopted consists of an arrangement of six
zigzag flues, three on each side of the setting. These flues run the
whole length of the setting. As indicated by the arrows pointing
downward in Fig. 3, the waste gases on their way to the chimney stack
pass to and fro through the side flues, thus giving up a large portion
of their contained heat by the process of conduction or contact to the
central flue through which the incoming air passes. The air necessary
for combustion is first admitted into a large chamber in the center, and
then it is divided into two currents, which pass right and left into the
central passages of the two regenerators. As the air flue is at a very
bright heat for a considerable distance before the air leaves it, the
temperature of the air must be equally great, or nearly so. In its most
improved form one of these heat regenerative furnaces provides an amount
of heating surface extending to 234 square ft., which is exposed to the
air on its way to the combustion chamber.

Passing from the producer through the flue provided for it, the gas
enters the retort setting underneath the side retorts, where it meets
the air coming from the regenerator. It enters the setting, not by a
number of small openings, but by one large opening on each side, and
meets the air entering also by a large opening, the effect of which is
to avoid the localization of intense heat, as all the retorts of the
setting become enveloped in an intensely heating flame, due to the
combustion of the carbonic oxide and hydrogen gases.

There are various advantages attending this system of firing gas
retorts. First of all, there is already a saving of fuel to the extent
of one-half, and not unlikely there will soon be a further very decided
increase in the saving of fuel to record, inasmuch as it has been
experimentally determined within the past two or three weeks that, by
increasing its diameter to 3 ft. 4 in., one producer can be made to
provide a sufficient amount of gaseous fuel to fire two sets of eight
retorts. By the arrangement just hinted at the relative amount of fuel
used will be still further reduced. Then, again, an additional retort
can well be placed in each oven, as it occupies the position of the fire
in ordinary settings. In the third place, by the greater heat which is
obtained, the charges can be more rapidly distilled; or heavier charges
can be carbonized in a given space of time. When all the gains are put
together, the amount of coal carbonized is increased by about 40 per
cent. over any specified time. Of course, in the new or regenerator
settings there is much greater regularity of heat; and as the gaseous
fuel is perfectly free from all solid matter, and burns without any
trace of smoke, there is a total absence of deposit on the outside of
the retorts. From these two circumstances combined it is but natural to
expect that there should be greater durability of the retorts--which
is really the case. Another advantage is that, as the fuel used in
the furnaces is wholly gaseous, choking of the flues cannot by any
possibility arise. It is the confident opinion of Mr. Foulis that the
system in question can be applied with advantage to all sizes of gas
works, and that it is certainly well adapted for all works where the
summer consumption of gas is sufficiently large to give employment to
eight retorts.

As this is the first instance of the new form of gas producer and
regenerator having been adopted in any gas works, a very great amount
of scientific and practical interest attaches to it. Many persons have
visited the Dalmarnock Gas Works during their reconstruction, in order
to see the system in operation, and doubtless many more will go and do
likewise when they learn of the numerous advantages which it possesses,
and which are likely to increase rather than diminish.--_Engineering_.

       *       *       *       *       *




A NEW GAS-HEATED BAKER'S OVEN.


During the past few weeks, a highly interesting experiment--and one,
moreover, destined to materially influence the development of the uses
of gas in a fresh field--has been in progress, under the guidance of Mr.
Booer, at a baker's shop in the Blackfriars Road, London. The experiment
in question is nothing less than the application of gas for heating
bakers' ovens, in a manner not hitherto attempted, and such as to bring
the system within the means of the poorest tradesman in all but the
smallest towns. It will be remembered that the success of the gas-heated
muffles for burning tiles and glass led to the attempted construction of
a model baker's oven, heated by the same fuel, which was shown in action
at the Smoke Abatement Exhibition at South Kensington in the winter
of 1881-82. This model attained considerable success; but its design
demanded either a new structure in every case, or considerable
alteration of any existing oven. In the proposed system, moreover,
the oven was heated wholly from without--a condition supposed to be
necessary to meet the objections of the bakers. It is evident, however,
that there must be considerable waste of gas in heating a mass of tiles
and brickwork, such as go to the construction of a common baker's oven,
from the outside; and the objection to handicapping such a costly fuel
as gas in this manner becomes more apparent when it is remembered that
in the usual way the oven is always heated by an internal coal fire.
When it is further considered that the coal commonly used by bakers is
of the most ordinary quality, full of dirt that would condemn it in the
estimation of a gas manager, the sentimental objection to allowing a
purified gas flame to burn in a place which this rubbish is permitted to
fill with foul smoke becomes supremely ridiculous. Consequently, when
Mr. Booer, whose work in connection with the gas muffle is well known
in England and America, seriously addressed himself to construct, upon
altogether new lines, a cheap and practical baker's oven, he wisely put
the gas inside.

There are many other conditions which Mr. Booer, after consultation with
practical bakers and others, set himself to fulfill, the observance
of which lends to the present Blackfriars experiment much of its
interesting character. Thus it was observed that, while it is not
difficult to build an oven in a given spot, and bake bread in it, this
cannot truly be called a _baker's_ oven. By this term must be understood
in particular an oven in an ordinary bakehouse, set in the usual style
and worked by a man with his living to get by it. Before the problem of
extending gas to bakers' ovens could be considered solved, it had to be
attacked from this aspect. Mr. Booer, to do him full credit, seems to
have early appreciated this fact in all its bearings. He not only saw
that it was necessary to save gas, as much as possible, by putting it
inside the oven; but he was told that, in order to meet with any general
success, the cost of converting an oven to the gas system must be
rigidly kept down to about ten or twelve guineas. The latter seems
a particularly hard condition, when it is remembered that the only
improved baker's oven in practical use at the present day is the steam
oven invented by Mr. Perkins, which costs two or three hundred pounds to
erect. Mr. Booer also had in mind the necessity that everything possible
for a coal oven must likewise be performed by a gas oven; and in this
respect he set himself to surpass the costly Perkins oven, which will
not bake the common "batch" or household bread, generally the principal
article of sale, more especially in populous and poor neighborhoods. The
peculiar efficacy of the common coal fire in this respect proceeds from
the essential principle of action of a brick oven, which is found simply
in the fact that the work is done entirely by heat previously imparted
to the tile bottom, roof, and sides of the oven, and thence radiated to
the bread. No other kind of heat will bake batch-bread--i.e., loaves
packed in contact with one another--which requires to be thoroughly
soaked by a radiant heat in a close atmosphere of its own steam. Now,
as a coal fire is eminently qualified to impart, by radiation and
otherwise, this necessary store of heat to the brickwork, it is plainly
a difficulty to effect the same purpose with a fuel which, of
itself, can scarcely radiate heat at all. The system of the gas
cooking-oven--the utilization of the heat of the combustion products as
formed--is clearly inapplicable here; for a different kind of heat is
needed, under conditions that would not sustain continuous combustion.
Therefore, there is nothing for it but to heat the bottom and sides
of the brick oven by the direct contact of powerful gas-flames; thus
supplanting the coal fire, but leaving the actual work of baking to be
done afterward by stored-up heat in the regular way.

Having settled the general principles of a system of this kind, there
still remain a number of scarcely less important details, in the dealing
with which lies the difference between practical success and failure.
Thus it is not merely sufficient to heat an oven for bread baking; it is
also necessary to heat it within the times and according to the habits
of work to which the baker has been accustomed. Work in town bakeries
begins at about midnight, or shortly after, and the condition of the
oven must conform to the requirements of the dough, which vary from day
to day and from season to season. In order to master all these niceties,
as far as a knowledge of them is necessary to his purpose, Mr. Booer
has spent many nights in the bakehouse in the Blackfriars Road; and has
thereby obtained a command over the technicalities of the work which has
served him in good stead, not merely for adjusting his gas heat, but in
answering the innumerable objections always raised when a revolution in
an immemorial trade is threatened. It is with considerable satisfaction
that we are enabled to declare, after duly weighing all the conditions
as to first cost and otherwise imposed by himself and others, that Mr.
Booer has succeeded, upon these terms, in vindicating the claims of gas
to be a cheap, efficient, and cleanly fuel for heating ovens under the
control and according to the methods of working of the baker himself.

The oven with which this success has been achieved is one of two in the
bakehouse of Mr. Loeber, of 161 Blackfriars Road. It measures 7 feet by
6 feet internally; being what is technically termed a 6 bushel oven. The
alterations made by Mr. Booer consist in the first place in the removal
of the flooring tiles, and the laying down of a new bottom, under which
run a number of flues radiating from the side furnace. The throat of the
furnace, where it enters the angle of the oven, is bricked up, and eight
pieces of ¾-inch gun-barrel tubing project above this dwarf wall,
and radiate fan-shaped under the dome of the roof. These are the
gas-burners, which are supplied from a 1½-inch pipe led into the old
furnace. The same pipe supplies the similar burners which are inserted
in the flues under the oven bottom. This is really all the plant
required. It should be remarked that these bottom flues are carried to
different points of the side walls, and the products of combustion are
allowed to rise upward into the oven through gaps left for the purpose.
A supplementary supply of heated air is provided to help the combustion
of the gas in these flues, which would otherwise be languid. When the
gas is turned on from the main cock in the furnace either to the top or
the bottom set of burners, a long match is used to light them from
the same point. This is effected without risk of firing back, by the
adoption of a specially constructed atmospheric nipple and shield, the
pattern of which is registered. The flame from the top burners unites in
a sheet of fire, which spreads out all over the crown of the oven, at
the same time that the burners below are doing their work, and the
products of combustion flow together through the oven to the chimney,
which is the same that was used for coal. At first, as might be
expected, there was considerable difficulty in finding the most suitable
position of the chimney damper, aggravated in this case by the fact that
the other oven worked with a coal fire into the same shaft. Finally,
however, the two flues were disconnected with the happiest results.
During the past fortnight the oven has been in regular use, and the
bread has been sold over the counter in the ordinary course of trade.
Two and three batches of bread have been baked in one day in this oven;
the economy of its use, of course, increasing with the number of loaves
turned out. As a rule the gas is lighted for about an hour before the
oven is wanted, and about 250 cubic feet are used. Then the cocks are
shut and the oven is allowed to stand closed up for ten minutes, in
which time it ventilates itself, and the heat spreads over it. Then the
batch is set, and the baking occupies from an hour to an hour and a
half, according to the different classes of loaves. Two batches are
baked with a consumption of about 620 cubic feet of gas; costing, at 2s.
10d. per 1000 cubic feet, just 11d. each batch for fuel. This cannot be
considered costly. But the system possesses many other advantages. In
the first place, it is much more cleanly than coal; for the oven never
requires wiping out, which is usually done with a bundle of old rope
called a "scuffle" and the operation is attended with a most unpleasant
odor. Then there is no smoke--a great advantage from the point of
view of the Smoke Abatement Institution. More to the purpose of the
journeyman baker, however, is the fact that there is no stoking to be
done, and he can therefore take his repose at night without having to
attend to the furnace. Besides this the master has the satisfaction of
knowing that the oven will always be hot enough if he simply attends to
the time of lighting the gas--a consideration of no small moment. It is
no mean testimony to the reality of Mr. Booer's success that Mr. Loeber,
having seen his difficulties and troubles from the beginning, and marked
how they have been overcome, is content to acknowledge that even this
first example is capable of turning out bread in a condition to be sold
over the counter. There is a good opening in this direction, for there
are 6,000 bakeries in London alone, to every one of which Mr. Booer's
system might be applied with advantage to the tradesman and his
customers. And what may be done with gas at about 3s. per 1,000 cubic
feet may certainly be done to still greater advantage in many towns
where the price is lower. Mr. Booer has entered upon his work in a
proper spirit. He has begun at the beginning, with the necessities of
the baker; and has gone plodding on quietly, until he has achieved a
noteworthy success. It may be hoped he will receive the reward which his
perseverance merits.--_Jour. of Gas Lighting_.

       *       *       *       *       *




CAPTAIN MATTHEW WEBB.


Who was drowned on July 24 in attempting to swim through the whirlpool
and rapids at the foot of the Falls of Niagara, was born at Irongate,
near Dawley, in Shropshire, January 18, 1848. He was 5 feet 8 inches in
height, measured 43 inches round the chest, and weighed about 14½ stone.
He learnt to swim when about seven years old, and was trained as a
sailor on board the Conway training-ship in the Mersey, where he saved
the life of a fellow seaman. In 1870 he dived under his ship in the Suez
Canal and cleared a foul hawser; and, on April 23, 1873, when serving on
board the Cunard steamer Russia, he jumped overboard to save the life of
a hand who had fallen from aloft, but failed, and it was an hour before
he was picked up almost exhausted. For this he received a gold and
other medals. He became captain of a merchant ship, but soon after he
relinquished the sea and devoted himself to the sport of swimming.

At long distance swimming in salt water he was _facile princeps_, but he
did not show to such advantage in fresh water. In June, 1874, he swam
from Dover to the North-East Varne Buoy, a distance of 11 statute miles.
On July 3, 1875, he swam from Blackwall Pier to Gravesend Town Pier,
nearly 18 statute miles, in 4 hours 52 minutes. On the 19th of the same
month he swam from Dover to Ramsgate, 19¼ statute miles, in 8 hours 45
minutes. On August 12, 1875, he tried to cross from England to France,
and although he failed, owing to the heavy sea, he compassed the
distance from Dover to the South Sand Head, 15½ statute miles, in 6
hours 48 minutes. On the 24th of the same month he made another attempt,
which rendered his name famous all over the English-speaking world.
Starting from Dover, he reached the French coast at Calais, after being
immersed in the water for 21 hours 44 minutes. He had swum over 39
miles, or, according to another calculation, 45½ miles, without having
touched a boat or artificial support of any kind. Subsequently he swam
at the Lambeth Baths, and the Westminster Aquarium, and last year, at
Boston, U.S., he remained in a tank nearly 128½ hours. Latterly he had
suffered from congestion of the lungs, and his health had become much
impaired.

[Illustration: CAPT. MATTHEW WEBB.]

The story of his final and fatal effort needs here but a brief
description. At two minutes past four, on July 24, Webb dived from the
boat opposite the Maid of the Mist landing, and, amid the shouts and
applause of the crowd, struck the water. He swam leisurely down the
river, but made good progress. He passed along the rapids at a great
pace, and six minutes after making the first plunge passed under the
Suspension Bridge. Immediately below the bridge the river becomes
exceedingly violent, and as the water was clear every movement of Webb
could be seen. At one moment he was lifted high on the crest of a wave,
and the next he sank into the awful hollow created. As the river became
narrower, and still more impetuous, Webb would sometimes be struck by a
wave, and for a few moments would sink out of sight. He, however, rose
to the surface without apparent effort. But his speed momentarily
increased, and he was hurried along at a frightful pace. At length he
was swept into the neck of the whirlpool. Rising on the crest of the
highest wave, he lifted his hands once, and then was precipitated into
the yawning gulf. For one moment his head appeared above the angry
waters, but he was motionless, and evidently at the mercy of the waves.
He was again drawn under the water, and was seen no more alive. Some
days later his body was found four miles below the fatal Rapids. It bore
tokens of the fearful violence of the struggle which he had undergone.
His bathing drawers were torn to fragments, and there was a deep wound
in his head. An inquest was held, and the jury returned a verdict of
"Found drowned."

Captain Webb was married about three years ago, and leaves a widow and
two children. It is understood that he risked his life in this last
fatal attempt to obtain money for the support of his family.--_London
Graphic_.

       *       *       *       *       *




SEMI-DETACHED VILLAS, BROMFIELD CRESCENT, HEADINGLEY.


These houses are situated in a pleasant part of Headingley, which is
the favorite residential suburb in the locality of Leeds. As regards
accommodation, the ground-floor of each house comprises good-sized
drawing and dining rooms, each with bay windows; well-lighted entrance
halls, opening upon wooden verandas; kitchen, pantry, and scullery; on
first floor are three good bedrooms, a bathroom, and other necessary
accommodation; on second floor are two additional bedrooms. The basement
contains coal-place and larder.

In these houses an attempt has been made to produce conveniently-planned
and well-arranged habitations, combined with a pleasing and picturesque
exterior, without involving a large outlay of money. The materials used
are brick of a deep red color for facings, red terra-cotta from Messrs.
Wilcock & Co., of Burmantofts, for moulded strings, sills, etc., and a
very sparing use of stone from the Harehills Quarries. The front gables
are constructed of timber in solid scantlings, well framed, and pinned
together with oak pegs, filled in and well backed behind with brickwork;
the panels faced with cement, which, together with the cored cornice,
are finished in vellum color. The whole of the woodwork of exterior is
painted a neutral shade of peacock blue, forming an admirable contrast
with the deep red of the bricks, the sashes and casements only being
finished in cream color. The whole of the chimneypieces in the interior
are carried out from the architect's special design; those in the
drawing-rooms being of mahogany, finished in rosewood color, and those
in dining-rooms of oak, stained with ammonia and dull wax polished.

[Illustration: SUGGESTIONS IN ARCHITECTURE.--SEMI-DETACHED VILLAS,
BROMFIELD CRESCENT, HEADINGLEY, LEEDS.]

The houses, with outbuildings and boundary walls, which have been
erected for Mr. John Hall Thorp, of Bromfield, Headingley, have cost
£1,450, or thereabouts, this amount not including the price of
land. They have been carried out from the designs and under the
superintendence of Mr. William H. Thorp, A.R.I.B.A., architect, of St.
Andrew's Chambers, Park Row, Leeds.--_The Architect_.

       *       *       *       *       *




THE DWELLINGS OF THE POOR IN PARIS.


In view of the possible approach of cholera, and the sanitary
precautions that even the most neglectful of authorities are constrained
to take, it is of some interest to us, says the _Building News_, to know
how the poor are housed in the city of Paris, which contains, more than
any city in the world, the opposite poles of luxurious magnificence
and of sordid, bestial poverty. The statistics of the Parisian working
classes in the way of lodgings are not of an encouraging nature, and
reflect great discredit on the powers that be, who can be stern enough
in the case of any political question, but are blind to the spectacle
of fellow creatures living the life of beasts under their very eyes. In
1880, the Prefect of Police gave licenses to 21,219 arrivals in the city
of French origin, and to 7,344 foreigners. In the succeeding year,
the former had increased to 22,061, while the latter had somewhat
diminished, being only 5,493. There was a census taken in 1881, from
which it appeared that Paris contained 677,253 operatives and 255,604
employes and clerks, while out of every 1,000 inhabitants, 322 only
were born in the city, and 565 came from the departments or the French
colonies. The foreign element in the working classes has increased
very rapidly, numbering 119,349 in 1876, to which by 1881 there was an
addition of 44,689. To every 1,000 inhabitants, Paris now numbers 75
foreigners, though in 1876 the proportion was only 60. It may not be
amiss to state that the annual increase of the Paris population is at
the rate of 56,043 persons, and that in the five years 1876-81, the city
received 280,217 additional mouths. The total population of the capital
is 2,239,928, of whom 1,113,326 are males.

Returning to the poorer classes, we find that in 1872 they were
estimated at 100,000; but that in 1873 they had risen to 113,733, and
in 1880 to 123,735. It is unfortunate to be obliged to say that the
majority of these people are housed worse in Paris than in almost any
other great city in the world. There are two classes of lodgings for the
poor--the one where the workman rents one or more rooms for his family,
and, perhaps, owns a little furniture; the other, a single room tenanted
for the night only by the unmarried man who pays for his bed in the
morning and gets his meals anywhere that he can. Readers will remember
how, under the auspices of M. Haussmann, western Paris was almost pulled
down and transformed into a series of palatial boulevards and avenues.
While the work lasted the Paris workman was well pleased; but he did
not like it quite so much when the demon of restoration and renovation
invaded his own quarters, such as the Butte des Moulins, and all that
densely populated district through which the splendid Avenue de l'Opera
now runs. The effect of all this was to drive the workman into the
already crowded quarters at the barriers, such as La Gare, St. Lambert,
Javel, and Charonne, where, according to the last statistics of the
_Annuaire_, the increase was at the rate of 415 per 1,000. Of course the
ill health that always pervaded these quarters increased also; and, from
the reports of Dr. Brouardel and M. Muller, the number of deaths from
typhoid and diphtheria were doubled in ten years. Dr. Du Mesnil, in
making his returns for 1881 of convalescents from typhoid, remarked that
the most unsanitary arrondissements were the 4th, 11th, 15th, 18th, and
19th--precisely those to which the principal migrations of laborers had
taken place. The 18th arrondissement, which in 1876 had only 601 lodging
houses with 8,933 lodgers, had, in 1882, over 850, with 20,816 inmates.
In the 19th arrondissement there were 517 houses in 1876, with 9,074
lodgers, and 752 in 1882, with 17,662 inhabitants.

It is not only the crowded condition of the poor quarters that is such a
standing menace to the health of the city, but also the shocking state
of the rooms, which the unhappy lodgers are obliged to put up with. The
owners of the property are, as happens in other places besides Paris,
unscrupulous and grasping to the last degree, and have not only divided
and subdivided the accommodation wherever possible, but have even raised
the rental in nearly all cases. Whole families are crowded into a small
apartment, icy cold in winter, an oven in summer, the only air and
daylight which reaches the interior coming from a window which looks on
to a dirty staircase or a still fouler court reeking with sewage. There
are at the present time in Paris 3,000 lodgings which have neither stove
nor chimney; over 5,000 lighted only by a skylight; while in 4,282 rooms
there are four children in each below 14 years of age; 7,199 with three
children; and 1,049 with four beds in each. The Parisian population has
augmented only 15 per cent. in seven years; but the district of poor
lodging houses has increased by twenty per cent., and the number of
lodgings by about 80 per cent. It is true that a law was passed in 1850
to provide for the sanitary supervision of this class of property; but
in Paris the law is a dead letter, and, although it is now active in the
provinces and in places like Marseilles, Lyons, Bordeaux, and Nantes, it
is applied, even there, in a jerky and intermittent manner.

Perhaps the worst of the abominable dogkennels called houses was the
group known as the Cité des Kroumirs, in the 13th arrondissement, which,
by a strange irony, was built on land belonging to the Department of
Public Assistance, which was let out by that body to a rich tenant, who
sublet it to these lodging-house owners. This veritable den of infection
and misery has now been demolished; but there are plenty of others quite
as bad. Notably, there is the Cite Jeanne d'Arc (a poor compliment to
have named it after that sturdy heroine), an enormous barrack of five
stories, which contains 1,200 lodgings and 2,486 lodgers. No wonder that
it was decimated in 1879 by smallpox, which committed terrible ravages
here. The Cité Dore is grimly known by the poor-law doctors as the
"Cemetery Gateway." The Cite Gard, in the Rue de Meaux, is inhabited
by 1,700 lodgers, although it is almost in ruins. The Cite Philippe is
tenanted by 70 chiffonniers, and anybody who knows what are the contents
of the chiffonnier's basket, or _hotte_, may easily guess at the
effluvia of that particular group of houses. A large lodging-house in
the Rue des Boulangers is tenanted by 210 Italians, who get their living
as models or itinerant musicians. Both house and tenants are declared to
be unapproachable from the vermin.

It is some satisfaction to know that these houses have lately awakened
the apathy of some of the public bodies, and that more than one
scheme is being put forward with a view of erecting proper industrial
dwellings. The Municipal Council is negotiating with the Credit Foncier
for the erection of a certain number of cheap houses, which, for the
space of twenty years, will be exempt from all taxes, such as
octroi, highway, door and window tax, etc. There are also one or
two semi-private companies, which are occupying themselves with the
question, and it is to be hoped that the rumors of the pestilence in
Egypt may hasten the much-needed reform.

       *       *       *       *       *

There can be no doubt, says the _Engineer_, that the inventor who could
supply in a really portable form a machine or apparatus that could give
out two or three horse power for a day would reap an enormous fortune.
Up to the present time, however, nothing of the kind has been placed
in the market. Gas is laid on to most houses now, and gas engines are
plenty enough, yet they do not meet the want which a storage battery may
be made yet perhaps to supply.

       *       *       *       *       *




RECENT EXPERIMENTS AFFECTING THE RECEIVED THEORY OF MUSIC.


To prove the incorrectness of Helmholtz's statement that beats do not
colesce into musical sounds, but that the ear will distinguish them as a
rumbling noise, even when their number rises as high as 132 vibrations
per second, Rudolph Koenig has constructed a series of tuning forks,
recently presented by President Morton to the Stevens Institute of
Technology. The following table exhibits the number of vibrations per
second of these forks, the ratios of their vibrations when two are
sounded together, the number of beats produced, and the resultant sound:

  Vibrations per second.         Ratio.        Beats.        Sounds.

  3840           :4096           15:16         128            Ut_{2}
  3904           :  "            61:64          96           Sol_{1}
  3936           :  "           123:128         80            Mi_{1}
  3968           :  "            31:32          64            Ut_{1}
  3976           :  "           497:512         60            Si_{-1}
  3989.3         :  "           187:192         53.3          La_{-1}
  4000           :  "           125:128         48           Sol_{1}
  4010.7         :  "            47:48          42.7          Fa_{-1}
  4016           :  "           251:256         40            Mi_{-1}
  4024           :  "           503:512         36            Re_{-1}
  7936           : 8192          31:32         128            Ut_{2}
  8064           :  "            63:64          64            Ut_{1}
  8096           :  "           253:256         48           Sol_{-1}
  8106.7         :  "            95:96          42.7          Fa_{-1}
  8112           :  "           507:512         40            Mi_{-1}
  8120           :  "          1015:1024        36            Re_{-4}
  8128           :  "           127:128         32            Ut_{-4}

On sounding two forks nearly in unison, the sound heard corresponds to
a number of vibrations equal to the difference of the numbers of
vibrations of the forks.

On sounding two forks, one of which is nearly the octave of the other,
the ear perceives a sound, which is that given by vibrations whose
number equals the difference in the number of vibrations of the higher
fork and the upper octave of the lower fork.

Koenig has also found out the laws of the resultant sounds produced
by other intervals than the octave, and has extended his researces to
intervals differing by any number of vibrations, as may be seen from the
above table.

His conclusion is that beats and resultant sounds are one and the same
phenomenon.

Thus, for example, the lowest number of vibrations capable of producing
a musical sound is 32 per second; in like manner, a clear musical sound
is produced by two simple notes of sufficient intensity which produce 32
beats per second.

Koenig also made a very ingenious modification of the siren for the
purpose of enabling Seebeck to sound simultaneously notes whose
vibrations had any given ratio. It is furnished for this purpose with
eight disks, each of which contains a given number of circles of
holes arranged at different angular distances. A description of this
instrument, which is also the property of the Stevens Institute, and of
Seebeck's experiments is thus given in a letter by Koenig himself.


I.

_Effects produced when the isochronism of the shocks is not perfect_.

A.

In order to produce a note, the succession of shocks must not deviate
much from isochronism.

If the isochronism is but little impaired, we obtain a note
corresponding to the mean interval of the shocks.

If the intervals between the shocks are alternately t and t', and if the
difference between t and t' is slight, we obtain the two notes t+t' and
(t+t')/2. If the intervals between the shocks are alternately t, t', and
t'', we obtain the two notes t+t'+t'' and (t+t'+t")/3.

Disk No. 1 has--

  On circle No. 1 12 holes, angular distances   t=30°
   "   "        2 24  "       "        "          15°
   "   "        3 36  "       "        "          10°
   "   "        4 36  "     at irregular distances.
   "   "        5 36  " distances t= 10½°, t'=l0°,t''=9½°
   "   "        6 36  "   "          11°      10°     9°
   "   "        7 36  "   "          16°      14°
   "   "        8 36  "   "          16½°     13½°

Circle No. 8 produces the two notes of circles 1 and 2; circle No. 7 the
same, but the low note is stronger than in 8.

Circle 6 produces the notes of circles 1 and 3, and so does circle 5,
but in the latter the low note is stronger than in 6.

Circle 4 produces a noise approximating only to the note of circle 3.

By pulling out one of the buttons of the wind chest, we admit the air
through eleven holes at a time, having an angular distance of 30° and
directing it against the corresponding circle of holes on the turning
disk. If the arrangement of holes is not repeated identically twelve
times on the same circle, we cannot, of course, make use of the above
arrangements of holes of the wind tube, and we must then employ one of
the movable brass tubes, which communicate with the interior of the wind
chest by means of rubber tubes and stopcocks. The experiment with disk
1, circle 4, for example, requires the use of one of these two tubes,
while the perforated wind tube of the wind chest may be used with all
the other circles of the same disk.

B.

If t is much less than t', while t' is a multiple of t, the note
(t+t')/2 disappears, and the notes t+t' and t are heard.

Disk No. 2 has--

  On circle No. 1 12 holes,  distances 30°
   "   "        2 36  "       "        10°
   "   "        3 48  "       "        7½°
   "   "        4 60  "       "         6°
   "   "        5 24  "       " t= 5°, t'=25°
   "   "        6 24  "            6°     24°
   "   "        7 24  "            7½°    22½°
   "   "        8 24  "           10°     20°

Circle 8 produces the notes of circles 1 and 2; circle 7, those of 1 and
3; circle 6, those of 1 and 4; and circle 5, the note of circle 1 and of
its sixth harmonic.

C.

If the same circular arc is divided into m and n equal parts; that is to
say, if mt=nt', we obtain the notes m and n.

Disk No. 3 has--

                                                       Distances.
  On circle No. 1 24 holes, distances 15°
   "   "        2 24   "        "     15° & 27 holes,   13-1/3°
   "   "        3 24   "        "     15° " 30   "      12°
   "   "        4 24   "        "     15° " 32   "      11-1/4°
   "   "        5 24   "        "     15° " 36   "      10°
   "   "        6 24   "        "     15° " 40   "       9°
   "   "        7 24   "        "     15° " 45   "       8°
   "   "        8 24   "        "     15° " 30, 36, & 48 holes

Circle 1 produces a single note, circle 2 a second, circle 3 a third,
circle 4 a fourth, 5 a fifth, 6 a sixth, 7 a seventh, and 8 a perfect
chord.


II.

_Experiments to prove that the shocks may proceed from two or several
different places to conspire in the formation of a note, provided that
the isochronism of the shocks is sufficiently exact, and that the shocks
are produced in the same direction_.

Disk No. 4 has--

  On circle 1 24 holes.
   "    "   2 36   "
   "    "   3 23   "
   "    "   4 12 at an angular distance of 10° from the holes
                  of circle 3.
   "    "   5 12 holes at an ang. dist. of 20° from those of circle 3
   "    "   6 12   "          "     "       0°        "
   "    "   7 12   "          "     "      15°        "
   "    "   8 12   "          "     "      15°        "

1. If from the same side two currents of air at an angular distance of
15° are directed against circle No. 8 of 12 holes, we obtain the octave
of the note produced by the same circle if only one current is used.

The wind-chest is provided with a special arrangement for this
experiment. By pulling out button 8, we give vent to 12 currents of air
spaced like the twelve holes of the disk; on pulling out button 9 we
also produce 12 currents, but they are situated just between the first.
Each of these two buttons pulled out alone will produce the same note
corresponding to 12 holes, but drawn together they produce the octave,
or the note of circle 1.

2. If two currents of air are directed against two similar circles whose
holes are situated on the same radii, we obtain the same result.

In this experiment, circles 7 and 8 are sounded by pulling out buttons 7
and 9.

3. When two currents of air are directed on the same radius against two
circles of similar holes arranged alternately, these circles sounded
simultaneously will produce the octave of the note which one of them
would give alone.

This experiment is performed by sounding circles 6 and 7 and pulling out
buttons 6 and 7.

4. If we direct three currents of air on the same radius against three
similar circles having holes alternating by a third of the distance
between two holes of the same circle, the three circles together produce
the fifth of the octave (Note 3) of a single circle.

Circles 3, 4, and 5 sounded together emit the note of circle 2.

(By sounding only two circles, 3 and 4, or 4 and 5, we make the same
experiment with two circles as disk No. 2 enabled us to make with
circle 8 alone; also, by sounding circle 3 alone, we obtain the note
corresponding to 12 holes; then pulling out button 4, the notes
corresponding to 12 and 36 holes are heard suddenly and very strongly;
but as soon as circle 5 is sounded also, the note of 12 disappears
completely, and we have left only that corresponding to 36 holes.)


III.

_Effects of interference produced by shocks in opposite directions_.

1. If we direct against a circle of holes two currents of air in
opposite directions, the note obtained with a single current is very
much weakened, if the two currents reach the holes simultaneously.
If the impulses are not isochronous, the intensity of the note is
increased.

2. If the two currents are directed against two circles of the same
number of holes, the effect is the same as for the two preceding cases.

3. If two currents of air are directed against two circles, one of which
has twice as many holes as the other, we obtain only the low note if
every shock of one is isochronous with every shock of the other.

We obtain the notes of both circles, one of which is the octave of the
other, if there is no isochronism between the shocks.

Disk No. 5 has three circles of 36, 36, and 72 holes. The air currents
are directed against the circles of holes through the movable tubes,
made so that they can be detached at pleasure. All these experiments
require great precision in the arrangement of these wind tubes. To make
sure that the tubes are simultaneously before two holes of the disk, it
is well to put little rods through the holes, reaching into the wind
tubes, and to remove them only when the tubes are firmly attached. The
experimenter should be careful also to place the two tubes exactly
at the same distance from the turning disk. It is clear that
notwithstanding all these precautions we never obtain perfect
interference, but only the weakening of notes that ought to disappear
entirely if all the arrangements were made with mathematical exactness,
and also if the ear could have absolutely the same position with regard
to impulses produced in opposite directions.


IV.

_Beats_.

Disk No. 6 has--

8 circles of holes to the number of 1, 2, 23, 24, 25, 47, 48, 49.

Circles 3 and 4, 4 and 5, 6 and 7, and 7 and 8 ought to produce as many
beats as circle 1 produces simple shocks; and circles 3 and 5, 6 and 8,
as many beats as circle 2 produces simple shocks; but we must content
ourselves in these experiments with a much less perfect result, for the
following reasons: The disk never being rigorously plane, alternately
approaches the single wind pipe and recedes from it. No matter how
slight this deviation is, every sound given by a single circle is heard
with periodical intensities which complicate the phenomenon. This
inconvenience could be avoided by placing several wind-pipes around the
circle; but while we can extend the period of the holes in two circles
(whose difference is 1) around the whole circle by blowing through a
single wind tube, we would be compelled to limit it to the distance
between two wind tubes, and it would become too short; for, when the
disk rotates with a velocity sufficient to produce notes high enough and
intense enough, the beats become too numerous to be easily perceived.

Besides these provisions, which sufficiently illustrate the points to
which we desire to call especial attention, Koenig also furnishes two
more disks.

The seventh contains 8 circles having 48, 54, 60, 64, 72, 80, 90, and
96 holes respectively. The 1st, 3d, 5th, and 8th will produce a perfect
chord when the air is admitted through the 11 holes in the wind chest;
with one wind tube the entire gamut may be obtained.

Finally the eighth disk contains 8 circles of holes, whose numbers are
in the ratio of 1:2:3:4, etc., and which may be used to illustrate
harmonics. C. F. K.

       *       *       *       *       *




THE MOTIONS OF CAMPHOR UPON THE SURFACE OF WATER.

[Footnote: Continued from SUPPLEMENT No. 391, page 6240.]


To have these movements occur in a constant and invariable manner upon
the surface of water, and especially upon mercury, it is necessary to
take precautions in regard to cleanliness, this being something that
we have purposely neglected to mention to our readers. For we wished,
through this voluntary omission, to stimulate their sagacity by bringing
them face to face with difficulties that they will perhaps have
succeeded in overcoming, with causes of error that they will have
perceived, and the principal one of which is the want of absolute
cleanliness in the water, vessels, and instruments that they may have
used for the experiments.

Thus, very probably, they will have more than once seen the camphor
remain immovable when placed in vessels in which they had hoped to
be able to see it undergo its gyratory and other motions. Their
astonishment will have been no less than our own was when we noticed
the sudden cessation of the camphor's motions under the influence of
vitreous or metallic objects, such as glass rods or tubes, pieces of
gold, silver, or copper coin, table knives, etc., dipped into the liquid
in which such motions were taking place before the immersion of the
objects under consideration.

The instantaneously _sedative_ power of the human fingers, or of a hair,
will have, perhaps, reminded them of some sort of sorcery, or of some
diabolic art worthy of the great Albert.

[Illustration: APPARATUS FOR THE STUDY OF THE MOTIONS OF CAMPHOR.]

As for ourself, we confess that, after repeating the curious experiments
of Mr. Dutrochet day after day, and scrupulously following his
directions, we have, in the presence of our results, that were exactly
identical with his, almost been tempted to believe ourself to be the
victim of some occult power, or at least of some optical illusion,
the true cause of which remained a mystery to us. Finally, after
many fruitless attempts to find a key to the enigma that engaged our
attention, the light finally dawned upon us, and then shone straight in
our eyes.

In comparing the last results of our experiments with those that we had
obtained previously, we saw, for example, that the camphor moved in the
test glasses at a level that was notably higher than that at which its
gyration took place the day before, or the day before that. And yet we
had always used the same vessels, the same water, and particles detached
from the same lump of camphor.

To what, then, could be due the difference observed between the two
levels at which we had, in the first and last place, seen the
camphor execute its movements? In the absence of any answer that was
satisfactory, we finally suspected that the difference that we had
noticed was ascribable to the fact that, after the numerous washings
that the apparatus had been submitted to in having water poured into
them to repeat the experiments, they had gradually been freed from
impurities of whatever nature they might have been, and which, unbeknown
to us, might have soiled their sides.

Starting with this idea, which was as yet a hyphothetical one, we began
to wash our hands, glasses, etc., at first with very dilute sulphuric
acid, and then with ammonia. Afterward we rinsed them with quantities of
water and dried them carefully with white linen rags that had been used
for no other purpose; and finally we plunged them again into very clean
water. We thus cut the Gordian knot, and were on the right track.

In fact, on again repeating Mr. Dutrochet's experiments, with that
minute care as to cleanliness that we had observed to be absolutely
necessary, we saw crumble away, one after another, all the pieces of
the scaffolding that this master had with so much trouble built up. The
camphor moved in all our vessels, of glass or metal, and of every form,
at all heights. The immersed bodies, such as glass tubes, table knives,
pieces of money, etc., had lost their pretended "sedative effect" on a
pretended "activity of the water," and on the vessels that contained
it. The so-called phenomenon of habit "transported from physiology into
physics," no longer existed.

The likening of the apparatus employed to obtain motions of camphor
upon water, with the entirely physiological apparatus by means of which
nature effects a circulation of the liquid contained in the internodes
of _Chara vulgaris_, had proved a grave error that was to be erased from
the science into which it had been introduced by its author with entire
good faith. The true cause of _life_ had not then been unveiled, and the
new agent designated as _diluo-electricity_ vanished before the very
simple and authentic fact that camphor moves rapidly upon the surface
of very pure mercury, in which no one would assuredly suppose that that
volatile substance could dissolve.

Mr. Dutrochet attaches great importance to the manner in which the water
is poured (with or without agitation) into the vessel with which
the experiment is performed. The matter is in fact of little or no
importance, and to prove this, it is only necessary to employ a test
glass (see figure) provided with a lateral tube, A, that terminates in a
lower tubulure, B, above which there is a contraction, C. Upon pouring
water into the lateral tube until the level reaches D, and placing
a particle of camphor on its surface, the camphor will be seen to
continually move about, even when the liquid has reached the upper
edge of the vessel. To reduce the level to various heights, it is only
necessary to revolve the tube in the cork through which it is fitted to
the tubulure. In proceeding thus, agitation or _collision_ of the water
is avoided; and yet if the test glass is very clean, the camphor will
continue to move at every level of the water.

But, some one will doubtless say, how do you explain the stoppage in the
motions of the camphor on the surface of water contained in vessels that
are not perfectly clean? Before answering this question, let us say in
the first place that the cause of the motions under consideration is due
to nothing else but the evaporation of this concrete oil--to effluvia
that escape from all parts and that exert upon the body whence they
emanate a recoiling action exactly like that which manifests itself in
an ælopile mounted upon a brasier, or, better yet, in the explosion of
a sky-rocket. A portion of these camphory vapors, as well as a small
portion of the camphor itself, dissolves in the water and forms upon its
surface an oily layer which is at first very slight, but the thickness
of which may increase in time until it becomes (especially if the vessel
is narrow) a mechanical obstacle to the gyration of the small fragments
of camphor that it imprisons, and whose evaporation it prevents. Now,
as this layer of volatile oil may and does evaporate, in fact, after a
certain length of time, the camphor then resumes its gyratory motions;
but there is not the least reason in the world for saying on that
account that it "has _habituated_ itself to the cause which had at first
influenced it, and that, too, in modifying itself in such a way as to
render null the influence of a cause that has not ceased to be present"
(Dutrochet, _l.c._., p. 50).

We have been enabled to convince ourself of the existence of this oily
layer of camphor when it was of a certain thickness by introducing under
the water on which it, had formed, a few drops of sulphuric ether whose
sudden evaporation produced sufficient cold to instantaneously congeal
the layer in question and thus render it perfectly visible to the eye.
The slight layer of greasy matter that habitually lines the sides of
vessels from whence no effort has been made to remove it, produces
effects exactly like those of the oil of camphor, that is to say, that
in measure as it becomes thicker it likewise arrests the motions of the
concrete volatile essence.

This is precisely what happens in a test-glass in which we see the
camphor in motion become immovable if the level of the water be raised a
few centimeters, and, more especially, if it be raised to the upper edge
of the apparatus. In its slow ascent the liquid _licks_ up, so to speak,
the oily layer that lines the inner surface of the vessel, and this
material spreads over the surface of the water and forms thereupon a
layer which, in spreading over the bit of camphor itself, prevents its
evaporation, and, consequently, its motions. The existence of the layer
under consideration cannot be doubted, since it is made to disappear by
causing the water to-overflow from the edges of the vessel, and, more
easily still, by spreading a piece of filtering paper over the liquid in
which the camphor is in a state of rest. As soon as the paper is
removed (without the water being touched by the fingers, it should be
understood), the camphor resumes its motions and afterward continues
them at all levels.

The fingers themselves, provided they are very clean, have no power to
stop the gyration. The following experiment, which is easy to repeat, is
an unquestionable proof of this.

Wash carefully the middle finger with aqua ammonia, and afterward with
plenty of water, and then dip it into a drinking glass in which a
fragment of camphor is rapidly moving, and the gyration will not be
stopped. But it will be made to stop instantly if the finger in
its natural state (that is, covered with the fatty substances that
ordinarily soil the fingers, especially in summer) be dipped into this
same glass.

_Movements of Camphor upon Mercury_.--In order to study the motions of
camphor, mercury possesses, as compared with water, a great advantage,
and that is that we can easily assure ourselves of the degree of
cleanliness of this metal by means of the condensed breath. The
vapory-deposits thereon in a uniform manner if the mercury is perfectly
clean, but forms variously shaded and more persistent spots if it is
soiled by foreign bodies But it is extremely difficult to clean mercury
completely. To do so Mr. Boisgiraud and I take distilled mercury and
leave it for a long time in contact with concentrated sulphuric acid,
taking care to often shake the mixture. Then, after removing the greater
part of the acid, we throw the metal into a vessel containing quick lime
in powder, and finally pass it through a filter containing a few holes
in its lower part.

Purified by this process, mercury not only permits of the motions of
camphor on its surface, but renders visible the traces of the vapors
that escape from it, and which resemble small tadpoles with a long tail
that are endowed with very great agility. Nothing is more curious than
to see the particle of camphor successively ascend and descend the
strongly pronounced curves presented by the mercury near the sides of
the vessel that contains it. On raising the temperature of the metal
slightly, the motions of the camphor on its surface are accelerated, and
the same effects occur with water that has been slightly heated.

The experiments that we have just called attention to show what
importance slight impurities may have upon certain results. "They
prove," says our learned colleague Mr. Daquin, "that there exists upon
polished substances an imperceptible coating of those fatty matters
which serve to-day to explain Moser's images." We find therein also a
manifest proof and a rational explanation of those grave errors into
which the presence of these fatty matters, that have hitherto been
scarcely suspected, led so clever and so distinguished a scientist as
the illustrious discoverer of endosmosis.--_N. Joly, in La Nature_.

       *       *       *       *       *




CARBONIC ACID IN BEER.


We present a diagram, on exposition at the last Brewers' Convention in
Detroit, of the racking device, devised by J. E. Siebel in 1872, and
used at that time in the brewery of Messrs. Bartholomae & Roesing, in
Chicago. The object of the apparatus is to retain as much carbonic acid
in the beer as possible while racking the same off into smaller packages
from the storage vats. The importance of this measure is apparent to
every one who knows what pains are taken to preserve the presence of
this constituent in all the former stages of the brewing process. In the
method of racking off which is in present use in most breweries, the
beer is forced through a rubber hose from the cask in the store vault to
the barrels, kegs, and smaller packages in the fill room. Owing to the
excess of pressure in the beer as it enters the keg, it is evident that
a large amount of the carbonic acid gas must escape. The escape of
carbonic acid during the process of racking off is indeed so large that
even a small difference in the pressure of the atmosphere causes a
remarkable difference in this respect. It is, therefore, evident that if
a larger pressure can be maintained while racking off, a larger amount
of carbonic acid gas will remain in the beer. It is true that the
racking off will take a little longer time if done under pressure, but
this inconvenience is certainly insignificantly small, when compared
with the other labors and troubles daily undergone in a brewery, for the
sole purpose to preserve in the beer the carbonic acid in that form in
which it has been formed during the fermentation, and in which form it
has far more refreshing and other valuable properties than in any
other form in which it may be subsequently introduced into the beer by
artificial means. The apparatus designed in the accompanying cut is
calculated to artificially produce a higher pressure of the atmosphere,
at least within the keg which is to be filled with beer. For this
purpose, the beer from the store cask running through the pipe, B,
enters the keg through a hollow copper bung, fitting light into the bung
hole by means of a rubber washer. The air contained in the keg, being
replaced by the beer, is forced out by means of the hollow copper bung,
taking its course through the pipe, inscribed "Glass Gauge," until it is
allowed to escape in the standpipe, C, containing a column of water,
the height of which designates the pressure within the keg, and a
consequently increased retention of carbonic acid gas. If the keg or
barrel is filled with beer, the same becomes apparent from the beer
showing itself in the glass gauge; then the faucet, B, is closed, the
copper bung is lifted out of the bung hole, and the beer contained in
the pipe is just sufficient to completely fill the keg, which is then
bunged up, while the apparatus is transferred to the next keg. Should
the attendant carelessly neglect to close the faucet in proper time, the
surplus beer will not necessarily be wasted, but will be collected in
the vessel, D, whence it can be drawn off through e.--_Chemical Review_.

[Illustration]

       *       *       *       *       *




ON THE DIFFERENT MODIFICATIONS OF SILVER BROMIDE AND SILVER CHLORIDE.


Hermann W. Vogel has made a comparative study of the properties of
silver bromide, obtained by precipitation in an aqueous solution of
gelatin, and those of the same compound prepared by precipitation in an
alcoholic solution of collodion. In 1874 Stas called attention to six
modifications of silver bromide. One of these, granular bromide of
silver, obtained by boiling the flocculent precipitate for several days
with water, he stated, was the most sensitive to light of all substances
known; exposure for two or three seconds to the pale blue flame of a
Bunsen burner being sufficient to blacken it. Important as this fact was
for photographers it was not applied for years, and it was only in
1878, when, it having been found that silver bromide precipitated in
a gelatine solution and boiled for several hours becomes much more
sensitive to light, that the remarks of Stas was recalled. Today these
observations have become of the greatest importance to practical
photography. They have led to the preparation of the silver bromide
gelatin emulsion and the silver bromide gelatin plates, which are twenty
times more sensitive than the silver iodide collodion plates, and have
become indispensable when impressions are to be taken in a dim light.

The extraordinary sensitiveness of silver bromide in gelatin seemed the
more remarkable since it was known that silver bromide in collodion is
only moderately sensitive. The explanation was sought for in various
directions, but as the result of numerous investigations it appears
that the chief cause of the difference is the presence of different
modifications of silver bromide. From a consideration of the work
already done on the subject, Vogel suspected that silver bromide
precipitated in an aqueous colloidal liquid would have notably different
properties from silver bromide precipitated in an alcoholic colloidal
solution. Silver bromide was prepared in many different ways. Emulsions
were made in bromide solutions containing gelatin or collodion (the
former aqueous, the latter alcoholic), some with the aid of heat, others
without. Part of the emulsion was then poured upon plates kept at a
moderate temperature and dried. The remainder was boiled or treated with
ammonia before being applied to the plates. He also precipitated silver
bromide in dilute gelatin or collodion solutions, allowed it to settle
completely, washed the precipitate, and mixed it with a new portion
of gelatin or collodion before applying it to the plates. Finally he
precipitated pure silver bromide, in the absence of all colloids, by
means of pure aqueous or alcoholic solutions of bromides and attempted
to bring this upon plates, using gelatin or collodion as a cement.
The result of all these experiments is that there are essentially two
modifications of silver bromide, the one being obtained by precipitation
in aqueous, the other in alcoholic solutions. The first, on account of
the position of the maximum of sensitiveness for the solar spectrum, he
calls blue sensitive, the other, for the same reason, indigo sensitive.

It is of no consequence whether the aqueous or alcoholic solution in
which the silver bromide is formed contains gelatin or collodion, or
whether the precipitation is effected with excess of bromide or of
silver nitrate. It makes no difference whether the solution is hot or
cold, or whether the silver bromide is treated with ammonia or
whether it is boiled or not. The only necessary condition is that in
precipitating indigo sensitive silver bromide the solutions must contain
at least 96 per cent of alcohol. From aqueous alcoholic solutions blue
sensitive silver bromide is precipitated.

Besides the difference of sensitiveness toward the solar spectrum, these
modifications of silver bromide exhibit other characteristic differences
in properties which indicate beyond a doubt that they are two
essentially different modifications of the same substance. Among these
are, 1st. Their unequal divisibility in gelatin or collodion solutions.
The indigo sensitive silver bromide cannot be distributed through a
gelatin solution, while the blue sensitive modification does so very
readily. 2d. Their unequal reducibility; the blue sensitive silver
bromide being reduced with much greater difficulty than the indigo
sensitive variety. 3d. Their different action toward chemical and
physical sensitizers. 4th. Their different action toward photographic
developers. 5th. Their different action under the influence of heat.
The blue sensitive variety if heated under water has its sensitiveness
perceptibly increased, while the other is not changed by such treatment.

A direct transformation of one modification into the other has not yet
been accomplished. The effect of the light upon these substances is
incipient reduction, and we might hence suppose that the more reducible
indigo sensitive variety would be the more sensitive to light. But
this is not the case, because it is not chemical reducibility, but the
absorption power for light that is of the greatest importance. Now the
blue sensitive silver bromide has a greater absorption power than the
indigo sensitive variety, and hence its greater sensitiveness. Silver
chloride prepared by methods similar to those used in making the two
forms of bromides was also found to exist in two modifications. One is
designated as ultra violet sensitive, the other as violet sensitive
silver chloride.--_Amer. Chem. Jour_.

       *       *       *       *       *




ANALYSIS OF A SAMPLE OF NEW ZEALAND COAL.

[Footnote: Read before the Society of Public Analysts on the 28th June,
1883.]

By OTTO HEHNER


Some discussion having recently taken place as to the value of New
Zealand coal as a fuel, the following results of a somewhat full
analysis may be worthy of being placed on record.

The sample to which the results refer consisted of large brownish
black lumps, many of which showed woody structure; the fractures were
conchyloid, the surface shiny and highly reflecting. It was interspersed
with a considerable amount of an amber colored resin. When powdered it
appeared chocolate brown. It burned readily, the flame being bright and
very smoky. Its ash was light and reddish brown.

It consisted of--

  Water (loss at 212° F.)        20.09
  Organic and volatile matter    75.19
  Ash                             4.72
                                ------
                                100.00

The organic and volatile constituents had the following percentage
composition--

  Carbon                         71.26
  Hydrogen                        5.62
  Oxygen                         21.58
  Nitrogen                        1.06
  Sulphur                         0.48
                                ------
                                100.00

The ash was composed of--

  Silica                         27.26
  Alumina                        26.48
  Oxide of iron                  12.98
  Lime                           20.19
  Magnesia                        3.42
  Sulphuric acid                  9.47
  Alkalies and loss               0.20
                                ------
                                100.00

From these figures the composition of the coal itself calculates as
under--

  Water                          20.09
  Carbon                         53.58
  Hydrogen                        4.23
  Oxygen                         16.23
  Nitrogen                        0.80
  Sulphur                         0.36
  Silica                          1.29
  Alumina                         1.25
  Oxide of iron                   0.61
  Lime                            0.95
  Magnesia                        0.16
  Sulphuric acid                  0.44
  Alkalies                        0.01
                                ------
                                100.00

One ton furnished 8,458 cubic feet of gas and 8 cwt. of coke.

The very high proportion of water contained in the sample is very
remarkable. It was so loosely combined, that even at ordinary
temperature it gradually escaped, the coal crumbling to small pieces.
The large amount as well as the high percentage of oxygen characterize
the so called coal as a _lignite_, with which conclusion the physical
characters of the sample are in perfect harmony.

The resin to which I have referred has not been further analyzed. It was
found to be insoluble in all ordinary menstrua, such as alcohol, ether,
carbon disulphide, benzene, or chloroform, and neither attacked by
boiling alcoholic potash nor by fusing alkali. On heating it swells up
considerably and undergoes decomposition, but does not fuse.

The coal may be valuable as a gas coal and for local consumption, but
the large proportions of water and of oxygen militate against its use as
a steam producer, only 58 per cent. of it being really combustible.

       *       *       *       *       *




DETERMINING MANGANESE IN STEEL, CAST IRON, FERRO-MANGANESE, ETC.

By E. RAYMOND.


The method in question is recommended as easy, expeditious, and
accurate. It consists in precipitating all the manganese in the state of
peroxide, dissolving it in a ferrous solution so as to bring back the
manganese to the manganous slate, and determining volumetrically, by
means of potassium permanganate, the quantity of ferrous salt which
has been converted into ferric. The method of rapidly precipitating
manganese peroxide is peculiar. If we act upon cast-iron or steel with
nitric acid and potassium chlorate in certain proportions, and boil
the mixture, the manganese is completely precipitated in the state of
peroxide insoluble in nitric acid, but retaining a small quantity of
ferric oxide. Suppose that we have a sample of steel or manganiferous
cast-iron containing less than 7 per cent of manganese. Three grammes
are treated in a small flask with 40 c. c. of nitric acid, of sp. gr.
1.20, added little by little. The liquid is stirred, and ultimately
heated to complete solution. It is withdrawn from the fire, and 15
grammes potassium chlorate are added, and then 20 c. c. of nitric acid
at sp. gr. 1.40. It is boiled for about fifteen minutes, until the
escape of chlorine ceases; all the manganese is found thrown down
as peroxide; hot water is added, the mixture is filtered, and the
precipitate washed with boiling water. To dissolve the manganese
peroxide thus obtained we measure exactly 50 c. c. of an acid solution
of ferrous sulphate, made up with 40 grammes ferrous sulphate to 750 c.
c. water and 230 c. c. sulphuric acid (full strength). The 50 c. c. are
poured into the flask in which the sample has been dissolved, and
to which a little peroxide adheres, and it is then poured upon the
precipitate and the filter in a Berlin-ware capsule. The manganese
peroxide dissolves very readily, transforming its equivalent of ferrous
sulphate into ferric sulphate. The liquid is then diluted to 100 or 150
c. c. for the next operation. We then take a solution of permanganate
formed by the same proportions as are used in determining iron by the
process of Margueritte (5.65 grammes of the crystalline salt per liter
of water), and determine its standard exactly. By means of this liquid
we determine volumetrically the quantity of ferrous sulphate remaining
in the solution of manganese. We take then 50 c. c. of the original
solution of ferrous sulphate diluted as above, and determine the total
ferrous salt.

The difference between the two determinations corresponds to the ferrous
salt which has been peroxidized by the manganese peroxide. The quantity
of iron thus peroxidized multiplied by 0.491 gives the quantity of
manganese contained in the portion operated upon. In the case of a
steel or cast iron containing but little manganese it is convenient to
dissolve the peroxide in 25 c. c. only of the ferrous solution. Small
Gay-Lussac burettes may then be used in the titration of only 0.010
meter internal diameter, and graduated into one-twentieth c. c., which
allows of great exactitude in the determination. For a spiegeleisen
not more than 1 gramme of the sample should be taken, and for a
ferro-manganese 0.3 gramme.

       *       *       *       *       *




MANGANESE AND ITS USES.


Manganese is one of the heavy metals of which iron may he taken as the
representative. It is of a grayish white color, presents a metallic
brilliancy, and is capable of a high degree of polish, is so hard as to
scratch glass and steel, is non-magnetic, and is only fused at a white
heat. As it oxidizes rapidly on exposure to the atmosphere, it should be
preserved under naphtha.

It occurs in small quantity in association with iron in meteoric stones;
with this exception it is not found native. The metal may be obtained by
the reduction of its sesquioxide by carbon at an extreme heat.

Manganese forms no less than six different oxides--viz., protoxide,
sesquioxide the red oxide, the binoxide or peroxide, manganic acid, and
permanganic acid. The protoxide occurs as olive-green powder, and is
obtained by igniting carbonate of manganese in a current of hydrogen.
Its salts are colorless, or of a pale rose color, and have a strong
tendency to form double salts with the salts of ammonia. The carbonate
forms the mineral known as manganese spar. The sulphate is obtained by
heating the peroxide with sulphuric acid till there is faint ignition,
dissolving the residue in water and crystallizing. It is employed
largely in calico printing. The silicate occurs in various minerals.

The sesquioxide is found crystallized in an anhydrous form in braunite,
and hydrated in manganite. It is obtained artificially as a black powder
by exposing the peroxide to a prolonged heat. When ignited it loses
oxygen, and is converted into red oxide. Its salts are isomorphous with
those of alumina and sesquioxide of iron. It imparts a violet color to
glass, and gives the amethyst its characteristic tint. Its sulphate is a
powerful oxidizing agent.

The red oxide corresponds to the black oxide of iron. It occurs native
in hausmannite, and may be obtained artificially by igniting the
sesquioxide or peroxide in the open air. It is a compound of the two
preceding oxides.

The binoxide, or peroxide, is the black manganese of commerce, and the
pyrolusite of mineralogists, and is by far the most abundant of the
manganese ores. It occurs in a hydrated form in varvicite and wad. Its
commercial value depends upon the proportion of chlorine which a given
weight of it will liberate when it is heated with hydrochloric acid, the
quantity of chlorine being proportional to the excess of oxygen which
this oxide contains over that contained in the same weight of protoxide.
When mixed with chloride of sodium and sulphuric acid it causes an
evolution of chlorine, the other resulting products being sulphate of
soda and sulphate of protoxide of manganese. When mixed with acids, it
is a valuable oxidizing agent. It is much used for the preparation of
oxygen, either by simply heating it, when it yields 12 per cent. of
gas, or by heating it with sulphuric acid, when it yields 18 per
cent. Besides its many uses in the laboratory, it is employed in the
manufacture of glass, porcelain, and kindred wares.

Manganic acid is not known in a free state. Manganate of potash is
formed by fusing together hydrated potash and binoxide of manganese. The
black mass which results from this operation is soluble in water,
to which it communicates a green color, due to the presence of the
manganate. From this water the salt is obtained _in vacuo_ in beautiful
green crystals. On allowing the solution to stand exposed to the air, it
rapidly becomes blue, violet, purple, and finally red, by the gradual
conversion of the manganate into the permanganate of potash; and on
account of these changes of color the black mass has received the name
of mineral chameleon.

Permanganic acid is only known in solution or in a state of combination.
Its solution is of a splendid red color, but appears of a dark violet
tint when seen by transmitted light. It is obtained by treating a
solution of permanganate of baryta with sulphuric acid, when sulphate of
baryta falls, and the permanganic acid remains dissolved in the water.
Permanganate of potash, which crystallizes in reddish purple prisms, is
the most important of its salts. It is largely employed in analytical
chemistry, and is the basis of Condy's Disinfectant Fluid.

Manganese is a constituent of many mineral waters, and is found in small
quantities in the ash of most vegetables and animal substances. It is
always associated with iron.

Various preparations of manganese have been employed in medicine. The
sulphate of the protoxide in doses of one or two drachms produces
purgative effects, and is supposed to increase the excretion of bile;
and in small doses, both this salt and the carbonate have been given
with the intention of improving the condition of the blood in cases of
anæmia. Manganic acid and permanganate of potash are of great use when
applied in lotions (as in Condy's Fluid diluted) to foul and fetid
ulcers. In connection with the medicinal applications of manganese it
may be mentioned that manganic acid is the agent employed in Dr. Angus
Smith's celebrated test for the impurity of the air.

It is the glass maker's soap of glass manufacture, and is used to
correct the green color of glass, which is owing to the presence of
protoxide of iron. This it converts into the comparatively colorless
peroxide.

It is also used in the Bessemer and similar processes, to decompose the
oxide of iron. Spiegeleisen, an iron which contains a natural alloy of
from 10 to 12 per cent. of manganese, is used for this purpose when
conveniently attainable.--_Glassware Reporter_.

       *       *       *       *       *




OZOKERITE, OR EARTH-WAX.

By WILLIAM L. LAY.

ON THE DEPOSITS OF EARTH WAX (OZOKERITE) IN EUROPE AND AMERICA.

[Footnote: Abstract from a paper read before the New York Academy of
Sciences.]


There exists a large mining and manufacturing industry in Austria, that
of ozokerite, or earth-wax, which has nothing like it in any other part
of the known world, an industry that supplies Europe with a part of its
beeswax, without the aid of the bees. It may not be generally known that
the mining of petroleum was a profitable industry in Austria long before
it was in this country. In 1852, a druggist near Tarnow distilled the
oil and had an exhibit of it in the first World's Fair in London.
In America, the first borings were made in 1859. Indeed, the use of
petroleum as an illuminator was common at a very early age in the
world's history. In Persia at Baku, in India on the Irawada, also in the
Crimea, and on the river Kuban in Russia, petroleum has been used
in lamps for thousands of years. At Baku the fire worshipers have a
never-ceasing flame, which has burned from time immemorial. The mines of
ozokerite are located in Austrian Poland, now known as Galicia. Near the
city of Drohabich, on the railway line running from Cracow to Lemberg,
is a town of six thousand inhabitants, called Borislau, which is
entirely supported by the ozokerite industry. It lies at the foot of
the Carpathian Mountains. About the year 1862, a shaft was sunk for
petroleum at that place. After descending about one hundred and eighty
feet, the miners found all the cracks in the clay or rock filled with
a brown substance, resembling beeswax. At first, the layers were not
thicker than writing paper; but they grew thicker gradually below, until
at a depth of three hundred feet they attained a thickness of three or
four inches. Upon examination, it was found that a yellow wax could be
made of a portion of this substance, and at once a substitute for wax
was manufactured.

The discovery caused an excitement like the oil fever of 1865 in
America. A large number of leases were made. When I saw the wells of
Pennsylvania, in 1879, there were more than two thousand. The owner
of the land received one-fourth of the product, and the miners
three-fourths. In the petroleum region, the leases at first were whole
farms, then they were reduced to 20, then 10, then 5, and at last to 1
acre, which is a square of 209 feet.

But in the ozokerite region of Poland, where everything is done on a
small scale, when compared with like enterprises in this country, the
leases were on tracts thirty-two feet square. These were so small that
the surface was not large enough to contain the earth that had to be
raised to sink the shaft; consequently the earth had to be transported
to a distance, and, when I saw it, there was a mound sixty or seventy
feet high. Its weight had become so great that it caused a sinking
of the earth, and endangered the shafts to such an extent that the
government ordered its removal to a distance and its deposit on ground
that was not undermined. The shafts are four feet square, and the sides
are supported by timbers six inches through, which leaves a shaft three
feet square. The miner digs the well or shaft just as we dig our water
wells, and the dirt and rock are hoisted up in a bucket by a rope and
windlass. But one man can work in the shaft at a time. For many years
no water was found; but, as there is a deposit of petroleum under the
ozokerite, at a depth of six hundred feet from the surface, the miners
were troubled with gas. This is got rid of by blowing a current of fresh
air from a rotary fan through a pipe extending down the shaft as fast as
the curbing of timber is put in place. The ozokerite is embedded in a
very stiff blue clay for a depth of several hundred feet; below, it is
interlaid with rock. [Specimens of crude and manufactured ozokerite were
on exhibition, through the kindness of Dr. J. S. Newberry.]

That part of the earth's surface has more miners' shafts to the acre
than any other part of the globe. As wages are very low in Poland,
averaging not more than forty cents a day for men and ten cents for
children, a very small quantity of ozokerite pays for the working. If
thirty or forty pounds a day is obtained, it remunerates the two men
and one or two children required to work each lease. When the bucket,
containing the earth, rock, and wax, is dumped in the little shed
covering the shaft, it is picked over by the children, who detach the
wax from the clay or rock with knives. The miners use galvanized wire
ropes and wooden buckets. When preparing to descend, they invariably
cross themselves and utter a short prayer. The business is not free from
danger, carelessness on the part of the boy supplying the fresh air, or
the caving in of the unsupported roof, causing a large number of deaths.
One of the government inspectors of the mines informed me that in one
week there had been eight deaths from accidents.

The ozokerite is taken to a crude furnace, and put into a common cast
iron kettle, and melted. This allows the dirt to sink to the bottom, and
the ozokerite, freed from all other solids, is skimmed off with a ladle,
poured into conical moulds, and allowed to cool, in which form it is
sold to the refiners, for about six cents per pound. The quantity
produced is uncertain, as the miners take care to understate it, for
the reason that the government lays a tax upon all incomes, and the
landowner demands his one-fourth of the quantity mined. The best
authority is Leo Strippelman, who states the quantity produced in
fifteen years at from 375,000,000 to 400,000,000 pounds, worth
twenty-four millions of dollars. As the owners of the land get
one-fourth of the sum, they received six millions. This is at the rate
of four hundred thousand a year, a rather valuable crop from some two
hundred acres of land.

The miners do not support the earth by timber or pillars, as they
should; the result is that the whole plot of about two hundred acres is
gradually sinking, and this will eventually ruin the industry in that
part of the deposit. In another part of the same field, a French company
has purchased forty acres, and it is mining the whole tract and hoisting
through one shaft by steam power. In that shaft they have sunk to a
depth of six hundred feet, and are troubled with water and petroleum.
These they pump out very much the same way as in coal and other mines,
worked in a scientific manner. The thickest layer of ozokerite found is
about eighteen inches, and this layer or pocket was a great curiosity.
When first removed at the bottom of the shaft, it was found to be so
soft that it was shoveled out like putty. During the night it oozed
into the space that had been emptied the day before; this continued for
weeks, or until the pressure of the gas had become too weak to force it
out.

I have been occupied in the petroleum region of Pennsylvania since 1860,
have seen all the wonderful development of the oil wells, and was very
much interested in contrasting the Austrian ozokerite and petroleum
industry with the American. It is a good illustration of the difference
between the lower class of Poles and Jews and the Yankee. Borislau,
after twenty years' work, was unimproved, dirty, squalid, and brutal. It
contained one school house, but no church nor printing office. None of
its streets were paved, and, in the main road through the town, the mud
came up to the hubs of the wagon wheels for over a mile of its length.
In places, plank had to be set up on edge to keep the mud out of the
houses, which were lower than the road. It contained numerous shops,
where potato whisky was sold to men, women, and children. It depends on
a dirty, muddy creek for its supply of water. Its houses were generally
one-story, built of logs and mud.

On the other hand, Oil City, a town of the same age and size, contained
eight school houses (one a high school building), twelve churches, and
two printing offices. It has paved streets, which, in 1863, were as deep
with mud as those in Borislau in 1879. It has no whisky shops where
women and children can drink. Many of its houses are of brick, two,
three, four, and five stories high. Its water works cost one hundred and
fifty thousand dollars. All this has been done since 1860, when it did
not contain forty houses.

I saw in the market place of Borislau women standing ankle deep in the
mud, selling vegetables. One woman really had to build a platform of
straw, on which to place a bushel of potatoes; if the straw foundation
had not been there, the potatoes would have sunk out of sight. Borislau
is three miles from Drohobich, a city of thirty thousand inhabitants;
between the two places, in wet weather, the road was impassable. For a
third of the way, it was in the bed of the creek; and I had to wait a
day for the water to fall so as to navigate it in a wagon. On inquiring
why they did not improve the road, I found the same difficulty as the
Arkansas settler encountered with his leaky roof; when it rained he
could not repair it, and when it was dry it did not need repair: so with
the road to Borislau.

Ozokerite (from the Greek words, "Ozein," to smell, and "Keros," wax) is
found in Turkistan, east of the Caspian Sea; in the Caucasian Mountains,
in Russia; in the Carpathian Mountains, in Austria; in the Apennines,
in Italy; in Texas, California, and in the Wahsatch Mountains, in the
United States. Commercially, it is not worked anywhere but in Austria;
although, I believe, we have in Utah a larger deposit than in any other
place. I made two journeys to examine the deposits in the Wahsatch
Mountains. For a distance of forty miles, it crops out in many places,
and on the Minnie Maud, a stream emptying into the Colorado, I found
a stratum of sand rock, from ten to twelve feet thick, filled with
ozokerite.

No systematic effort has been made to ascertain the quantity of
ozokerite in Utah. I saw a drift of some fourteen feet at one place, and
a shaft twenty-three feet deep at another. In this shaft, the vein was
about ten inches wide; and it could be traced along the slope of the
hill, for several hundred feet. The largest vein of pure ozokerite is
seen on Soldiers' Fork of Spanish Cañon, which enters Salt Lake Valley
near the town of Provo. This vein is very much like the ozokerite of
Austria, and contains between thirty and forty per cent. of white
ceresin (which resembles bleached beeswax), about thirty per cent. of
yellow ceresin (which resembles yellow wax), and twenty per cent. of
black petroleum; the residue is dirt. Dr. J. S. Newberry, of Columbia
College, and Prof. S. B. Newberry, of Cornell University, made
examinations of the ozokerite found in Utah; those who are interested
in the subject will find the papers published in the _Engineering and
Mining Journal_ for the year 1879.

A deposit of white ozokerite occurs on the top of the Apennine
Mountains, in Italy, of which a specimen is here exhibited. An
interesting story is told of its discovery. A church at Modena was
robbed; among other articles taken was a quantity of wax candles. A
short time afterward, a woman brought to a druggist a quantity of wax
and offered it for sale. The druggist bought it and afterward suspected
it consisted of the stolen candles melted down. Soon after ward she
brought another lot. He had her arrested. When questioned by the
magistrate, she said she found the wax in the clay on her farm, about
twenty miles from the city. This story confirmed him in the belief that
she had stolen the candles, or was the receiver of the stolen goods; for
such a thing as a deposit of wax in the soil was unheard of. She was
therefore remanded to jail. On three several days, she was brought
before the court, and, when questioned, told the same story. She was a
member of the church, and requested the priest to be sent for. He came,
and, after an interview between them, he said it was easy to disprove
her story, if it was a lie, by sending her home, in company with an
officer, to investigate. The court sent the priest, who was the only one
who believed her. On coming to her house, she took her pick and shovel,
and going to the place at the top of the hill, she dug out of the clay
a quantity of while ozokerite, proved her case, and was at once set at
liberty. She performed the same service for me, and I saw her dig the
specimen and heard her tell the story as I have told it to you. The hill
was composed of loose clay and stones. It appeared as if it had been
forced up by gas or some power from below the surface. The quantity that
could be gathered, by one person, laboring constantly for a week, was
only twenty-five or thirty pounds. An attempt had been made to sink a
shaft; but, at a depth of fourteen feet, the pressure of the clay was
sufficient to break the boards that held up the sides. The earth caved
in, and the shaft was abandoned.

It is not necessary here to describe the various processes of
manufacture; it will be sufficient to enumerate some of the forms of
ozokerite, and the uses to which it is put. At Borislau, there are
several refineries, where candles, tapers, and lubricating oils are
made. In Vienna, there are five factories; in one of these, they make
white wax, wax candles, matches, yellow beeswax, black heel-ball,
colored tapers, and crayon pencils. In Europe, large quantities of the
yellow wax are used to wax the floors of the houses, many of the finer
ones being waxed every day. It is a curious fact that the Catholic
Church does not allow the use of paraffine, sperm, or stearine candles;
at the same time nearly all the candles used in the churches in Europe
are made from ozokerite, which is a natural paraffine, made from
petroleum in nature's laboratory. In the United States, the only
uses made of ozokerite, so far as I know, are chewing gum and the
adulteration of beeswax. In this the Yankee gives another illustration
of the ruling passion strong in money making, which gives us wooden
nutmegs, wooden hams, shoddy cloth, glucose candy, chiccory coffee,
oleomargarine butter, mineral sperm oil made from petroleum, and beeswax
made without bees.

After this paper was written, the following translation from a pamphlet,
published by the First Hungarian Galician Railway Company, in 1879, came
to my notice. The writer's name is not published:

"Mineral wax, in the condition in which it is taken from the shafts,
is not well adapted for exportation, since it occurs with much earthy
matter; and, at any rate, an expensive packing in sacks would be
necessary. It is therefore first freed from all foreign substances by
melting, and cooled in conical cakes of about 25 kilos. weight, and
these cakes are exported. There are now, in Borislau, 25 melting works,
which, in 1877, with 1 steam and 60 fire kettles, produced 95,000 metric
centners (9,500,000 lb.).

"The melted earth wax is sent from Borislau to almost all European
countries, to be further refined. Outside of Austro-Hungary, we may
specially mention Germany, England, Italy, France, Belgium, and Russia
as large purchasers of this article of commerce.


"PRODUCTS AND THEIR APPLICATIONS.

"The products of mineral wax, are:

"(a.) _Ceresine_, also called ozocerotine or refined ozokerite, a
product which possesses a striking resemblance to ordinarily refined
beeswax. It replaces this in almost all its uses, and, by its cheapness,
is employed for many purposes for which beeswax is too dear. It is much
used for wax candles, for waxing floors, and for dressing linen and
colored papers. Wax crayons must be mentioned among these products. The
house of Offenheim & Ziffer, in Elbeteinitz, makes them of many colors.
These crayons are especially adapted to marking wood, stone, and iron;
also, for marking linen and paper, as well as for writing and drawing.
The writings and drawings made with these crayons can be effaced neither
by water, by acids, nor by rubbing.

"Concerning the technical process for the production of ceresine, it
should be said that, when the industry was new (the production of
ceresine has been known only about eight years, since 1874), it was
controlled by patents, which are kept secret. This much is known, that
the color and odor are removed by fuming sulphuric acid.

"From mineral wax of good quality about 70 per cent. of white ceresine
is obtained. The yellow ceresine is tinted by the addition of coloring
matter (annatto).

"(b.) _Paraffine_, a firm, white, translucent substance, without odor.
It is used, chiefly, in the manufacture of candles, and also as a
protection against the action of acids, and to make casks and other
wooden vessels water-tight, for coating corks, etc., for air-tight
wrappings, and, finally, for the preparation of tracing paper. There
are several methods of obtaining paraffine from ozokerite (see the
Encyclopedic Handbook of Chemistry, by Benno Karl and F. Strohmann, vol.
iv., Brunswick, 1877).

"The details of the technical process consists, in every case, in the
distillation of the crude material, pressure of the distillate by
hydraulic presses, melting, and treating by sulphuric acid.

"In the manufacture of paraffine from ozokerite, there are produced from
2 to 8 per cent. of benzine, from 15 to 20 per cent. of naphtha, 36
to 50 per cent. of paraffine, 15 to 20 per cent. of heavy oil for
lubricating, and 10 to 20 per cent. of coke, as a residue.

"(c.) _Mineral oils_, which are obtained at the same time with
paraffine, and are the same as those produced from crude petroleum,
described above. The process consists, as in the natural rock oils,
besides the distillation, in the treatment of the incidental products
with acids and alkalies.

"Of the products of ozokerite, manufactured in Galicia, the greater part
goes to Russia, Roumania, Turkey, Italy, and Upper Hungary. The common
paraffine candles made in Galicia--which are of various sizes, from
28 to 160 per kilo--are used by the Jews in all Galicia, Bukowuina,
Roumania, Upper Hungary, and Southern Russia, and form an important
article of commerce. Ceresine is exported to all the ports of the world.
Of late a considerable quantity is said to have been sent to the East
Indies, where it is used in the printing of cotton."

The President, Dr. J. S. Newberry, stated that ozokerite was undoubtedly
a product of petroleum. Little was known by the public concerning its
use and value. He exhibited specimens of natural brown ozokerite, of
yellow ozokerite, sold as beeswax, and of a white purified form, which
had been treated by sulphuric acid. Specimens from Utah had already been
shown before the Academy. There was no mystery as to its genesis in
either region, as it had been shown to be the result of inspissation of
a thick and viscid variety of petroleum. The term "petroleum" includes a
great variety of substances, from a limpid liquid, too light to burn,
to one that is thick and tarry. These differ widely also in chemical
composition: some yielding much asphalt by distillation, resembling a
solution of asphalt in turpentine; some containing so much paraffine
that a considerable quantity can be strained out in cold weather. The
asphalt in its natural form is a solid rock, to which the term "gum
beds" has been applied in Canada. These differences in constitution have
originated in the differences in the bituminous shales from which the
petroleum, ozokerite, etc., have been derived. In Canada, as excavations
are sunk through the asphalt, this becomes softer and softer, and
finally passes into petroleum. This is also the case in Utah.

       *       *       *       *       *

[Concluded from SUPPLEMENT No. 400, page 6390.]

[KANSAS CITY REVIEW.]




THE SOLAR ECLIPSE OF MAY 6, 1883.


Professor C. S. Hastings, of the Johns Hopkins University, also includes
many interesting details in his account of the trip:

The voyage from New York to Panama was pleasant with the exception of a
few hot days near Aspinwall. Somewhat further south the wind changed,
obliging them to call their overcoats from the bottom of their trunks to
keep out the cold when crossing the equator. During a short stop in
Lima the party had an opportunity of studying South American life. The
products of this country are fruits and photographs of the young women.
The party enjoyed both eating the former and bringing the latter home
for the admiration of their friends. The expedition really began at
Callao, where the party embarked on the United States man-of-war
Hartford. Few circumstances contributed more to the enjoyment of the
trip than the lucky chance which threw this vessel in their way. The
Hartford was fitted out last August as flag ship of the South Pacific
squadron. The admiral had not yet removed his flag to the vessel, but
the extra accommodations provided for him and his train condoned the
dignity lost by his absence. On March 22 they weighed anchor for a sail
of more than four thousand miles over the blue ocean which stretches
between Callao and their destination, Caroline Island. The southeast
trade winds favored them, and from the first day there was actually no
necessity for altering the position of a sail....

The inhabitants--five men, one woman and two children, according to
the eclipse census--are natives of Tahiti. The houses are one story
structures with clapboard sides, probably cut out in California and
brought out in ships, to be erected on this island. The island on which
they are built is about three-fourths of a mile in diameter and nearly
circular in outline. The edge, which rises from five to twenty inches
from the water, according to the tide's phase, goes down under the water
to an even table of coral running out many feet into the sea; and is
impossible to step on it with bare feet. At the end of this table the
reef goes down perpendicularly, a sheer precipice, into the unfathomable
sea. No vessel can anchor here, and to make a landing was an exciting
matter. The island was approached in small boats on the side sheltered
from the wind, and here, with the luck which characterized the trip, was
found the only opening in this barrier of coral. A long cleft, perhaps
eight feet wide, at the outer edge of the reef, ran in, narrowing to a
mere crack near the shore. Watching a favorable chance, the boats were
guided through the surf into a cleft as far as shoal water, when the
men jumped on to the reef and carried baggage and instruments ashore as
quickly as possible. The boats, which were new when they entered the
surf, came out much the worse for wear, and the boat in which Dr.
Hastings landed was stove in. Once on shore, life became a succession of
wonders, rivaling the tales of Gulliver, and needing the conscientious
descriptions of exact scientists to make them credible.

The members of the observing party took up their abode in the larger of
the three houses, sleeping in swinging cots slung from the verandas,
which afforded shade on three sides of the building. The second house
was occupied by the sailors, while the third was left to the natives.
These latter were sufficiently conversant with English to serve as
excellent guides. Each day the party bathed in a lagoon in the center of
the island. This lagoon was bordered by a beach of dazzling white coral
sand, and all through its water extended reefs of living coral of
the more delicate and elaborate kinds. These corals gave the lake a
wonderful variety of colors, forming a picture impossible to paint or
describe, and with the least ripple from a passing breeze the whole
scene changed to new groups of color. The water was very clear, and
in some places deep; in others so filled with coral that a boat could
barely skim over the surface without scraping the keel. After crossing a
long reef, one day, they entered on a sheet of water so deep that their
longest line would not reach the bottom, plainly visible beneath. Fish
swarmed here, and it was characteristic of them that every species, if
not brilliantly colored, was marked in the most peculiar manner. One
variety which frequented the shallow water, where it was heated to the
degree uncomfortable to the touch, was a pure milky white, with black
eyes, fins, and tail.

The French party arrived two days after the Americans. They had steamed
directly from Panama with the hope of anticipating the Americans.

It rained on the morning of the eclipse, but cleared off in good time,
and the definition was particularly good. Photographs occupied the time
of the English and French observers. Professor Holden and Dr. Dickson
searched for intra-mercurial planets; Mr. Preston took the times of
contact; Dr. Hastings and Mr. Rockwell devoted their attention to
spectroscopic observations of the corona. Dr. Hastings' observations
have led to the production of a new theory of the corona. Briefly
stated, the theory is that the light seen around the sun during a total
eclipse is not due to a material substance enveloping the sun, but is a
phenomenon of diffraction.

From his observation during the eclipse of 1878, made at Central City,
Dr. Hastings conceived the first idea of this explanation of the solar
corona. Further study served to convince him of the truth of this
theory, but he had no means of proving it. Before the present eclipse,
however, he devised a crucial test of his theory. This test is based on
the following already known phenomena: When the moon covers the face of
the sun, an envelope of light is seen all round it; the envelope is
not visible when the sun is shining, on account of the sun's greater
brightness; this light is called the corona; it is extremely irregular
in outline. According to the drawing of Mr. J. E. Keeler at the eclipse
of 1878, it enveloped the sun as a hazy glow, extending for a distance
of several minutes of arc from the sun's limb and at two nearly opposite
points is extended out in two long streamers feathering off into space.
The opinion has been that this light was due to an atmosphere extending
millions of miles from the sun. According to Dr. Hastings' view, it must
be light from the sun which has undergone refraction, i.e., which has
been bent from its regular course by the interposition of an opaque body
like the moon.

In order to make this perfectly plain, suppose the front of a surface
of waves of any sort to be striking an object which resists them. If
an organ of sense is placed in the resisting object, it will judge the
direction of the waves or the direction of the object producing them by
a line at right angles with the wave front. Now suppose a body is placed
between the body producing the waves and the sensitive organ. The waves
must go around this body and will produce an eddy behind it, so that the
wave front will have a different direction, and the organ of sense will
conceive the origin of the waves to lie in a direction different from
that before the body was interposed. Now consider the waves to be waves
of light, and their origin the sun. The organ of sense is the retina of
the eye. The moon is the opaque body interposed in the course of the
waves, and they, being bent, make the impression on the eye that the
light comes from beyond the edge of the sun. The moon covers the sun
during the eclipse and a little more, so that it can move for about five
minutes and still cover the sun entirely. This movement is very slight,
and if the corona consists of light from a solar atmosphere, it should
not change at all during this movement of the moon. But if diffraction
is the cause of the light, then the slightest change in the relative
positions of the sun and the moon should change the configuration of the
corona, i.e., the corona should not remain exactly the same during
a total eclipse. The character of the light as shown by a spectrum
analysis should change.

To determine this point Dr. Hastings invented the following instrument:
Two lozenge-shaped prisms of glass were fastened in the form of a letter
V, and so arranged that all the light falling within the aperture of
the V was lost, and that falling on the ends of the glass prisms was
transmitted by a series of reflections to the apex of the V, where the
prisms touched; here was placed a refracting prism, so that the light
could be analyzed. This instrument was attached to the eye piece of the
telescope, and the image of the eclipse reduced to such a size that the
moon just fitted into the aperture of the V, while opposite sides of the
corona were reflected through the prisms to the place where they came
together. In this way both sides of the corona were seen through the
eye-piece at the same time. On looking at the eclipse this is what Dr.
Hastings saw: The light of the corona was divided into its constituents.
Prominent among them was a bright green line, which is designated by the
number 1,474; to this line attention was directed. Its presence in the
spectrum has been an argument in favor of the view that the corona is
a solar atmosphere. If this is the case, the line should remain fixed
during the eclipse; but if the corona is due to diffraction, this line
should change. It should grow shorter in the light from one side of the
corona, and longer on the other. The observation was now reduced to
watching for a change in the relative length of two green lines.

At the beginning of totality the line from the west side was much the
longer, but as the eclipse progressed it shortened notably, while the
line from the east side, shorter by about one-third at the beginning of
the eclipse, grew longer. When the eclipse ended, the proportions of the
lines were exactly reversed. There had been a change equal to two-thirds
the length of the lines, while the sun and moon had only changed their
relative positions by an extremely small amount. The only way in which
this phenomenon can be accounted for is on the diffraction theory. The
material view of the corona will not answer for it. But there are other
discrepancies in the older view which have been known for some time.
The principal ones are: 1. It is known from study of the sun that the
gaseous pressure at the surface must be less than an inch of mercury,
and is probably less than one-tenth of an inch, but an atmosphere
extending to the supposed limits would cause an enormous pressure at the
sun's surface, especially since the force of gravity on the sun is very
much greater than on the earth. 2. The laws of gravitation would require
a solar atmosphere to be distributed symmetrically around the sun, while
the corona is enormously irregular in form. The sun is irregular in
outline, which would make its diffracted phenomena show the observed
irregularity, but it is symmetrical as regards density. 3. The most
interesting discrepancy of the theory of the solar atmosphere is the
fact that while it is supposed to extend for millions of miles from the
sun, the recent comet passed within two hundred thousand miles of the
sun, and yet its orbit was not affected in the least, as it would have
been if it had plowed its way through a material substance. In taking
photographs of the corona it is seen to be larger as the time of
exposure is longer. This shows that the corona extends indefinitely, and
it decreases in brilliancy in exact accordance with the mathematical
laws of diffraction. These laws involve very complicated mathematics,
but by them alone Dr. Hastings has proved that there must be diffraction
where the corona is, and that it must follow the same laws as those
observed. There is a small envelope around the sun, but in the opinion
of Dr. Hastings it does not extend beyond what is known as the
chromosphere.

       *       *       *       *       *

The question seems to be settled, with considerable certainty, that
nothing exists inside of Mercury large enough to be dignified by
the name of planet. There may be, and there probably are, for the
perturbations of Mercury indicate it, multitudes of small masses
circulating around the sun like the planets, being fragments of comets
or condensations of primitive matter, whose combined luster is seen in
the zodiacal light.

The other results of the work of the Commission, so far as now known,
are connected with the structure of the corona, the solar appendage
which extends out for millions of miles from the sun's disk. In the
photographs of the Egyptian eclipse of last summer these streamers can
be traced back of each other where they cross; no better proof of their
extreme tenuity could be given.

The duration of an eclipse of the sun depends on three things, the
distance of the sun from the earth, the distance of the moon from the
earth, and the distance of the station from the equator. All of these
were favorable to a long eclipse in the case of the recent one, and the
six minutes of totality gave opportunities for deliberate work not often
enjoyed.

       *       *       *       *       *




A BURIED CITY OF THE EXODUS.


The excavations at Tell-el-Maskhutah, of which illustrations are given,
have resulted in some of the most interesting and important discoveries
that have ever rewarded the labors of archæologists. The idea of
founding an English society for the purpose of exploring the buried
cities of the Delta originated with Miss A. B. Edwards, the well-known
authoress of "One Thousand Miles up the Nile," and was carried into
effect mainly by her own efforts and the energy and zeal of Mr. Reginald
Stuart Poole, of the British Museum, aided by the substantial support of
Sir Erasmus Wilson, without whose munificent donations the work could
never have been accomplished. The "Egypt Exploration Fund," thus founded
and maintained, was fortunate in securing the co-operation of M.
Naville, the distinguished Swiss Egyptologist, who set out for Egypt
in January of this year with the object of conducting the explorations
contemplated by the society. After a consultation with M. Maspero, the
Director of Archæology in Egypt, who has throughout acted a friendly
part toward the society's enterprise, M. Naville decided to begin his
campaign by attacking the mounds at Tell-el-Maskhutah, on the Freshwater
Canal, a few miles from Ismailia. The mounds of earth here were known to
cover some ancient city, for some sphinxes and statues had already
been found; but what city it could be, archæologists were at a loss to
determine; though some, with Professor Lepsius at their head, believed
it to be none other than the Rameses or "Raamses," which the Children of
Israel built for Pharaoh, and whence they started on their final Exodus.
Any identification, however, of the sites of the Biblical cities in
Egypt was so far merely speculative. Practically nothing definite was
known as to the geography of the Israelite sojourn, except that the Land
of Goshen was undoubtedly in the eastern part of the Delta, and that
Zoan was Tanis, whose immense mounds are to form the next subject of
the society's operations. The route of the Exodus was as uncertain as
everything else connected with Israel's sojourn in Egypt. What sea they
crossed, and where, and by what direction they journeyed to it, remained
vexed questions, although Dr. Brugsch had set up a plausible theory, in
which the "Serbonian Bog" played an important part.

[Illustration: THE EXCAVATIONS PITHOM-SUCCOTH]

Six weeks of steady digging at Tell-el-Maskhutah, under M. Naville's
skillful direction, placed all these speculations in quite a new light.
The city under the mounds proved to be none other than Pithom, the
"store" or "treasure city" which the Children of Israel "built for
Pharaoh" (Exod. i. 11). Its character as a store place or granary is
seen in its construction; for the greater part of the area is covered
with strongly built chambers, without doors, suitable for the storing of
grain, which would be introduced through trap doors in the floor
above, of which the ends of the beams are still visible. These curious
chambers, unique in their appearance, are constructed of large, well
made bricks, sometimes mixed with straw, sometimes without it, dried in
the sun, and laid with mortar, with great regularity and precision. The
walls are 10 ft. thick, and the thickness of the inclosing wall which
runs round the whole city is more than 20 ft. In one corner was the
temple, dedicated to the god Tum, and hence called Pe-tum or Pithom, the
"Abode of Tum." Only a few statues, groups, and tablets (some of which
have been presented to the British Museum) remained to testify to its
name and purpose; the temple itself was finally destroyed when the
Romans turned Pithom into a camp, as is shown by the position of the
limestone fragments and of the Roman bricks. The statues, however, and
especially a large stele, are extremely valuable, since they tell the
history of the city during eighteen centuries. From a study of these
monuments, M. Naville has learned that Pithom was its sacred, and Thukut
(Succoth) its civil, name; that it was founded by Rameses II., restored
by Shishak and others of the twenty-second dynasty; was an important
place under the Ptolemies, who set up a great stele to commemorate the
founding of the city of Arsinoë in the neighborhood; was called Hero or
Heroöpolis by the Greeks (a name derived from the hieroglyphic _ara_,
meaning a "store house"), and Ero Castra by the Romans, who occupied it
at all events as late as A.D. 306. Indications are also found of the
position of Pihahiroth, where the Israelites encamped before the
passage of the "Reedy Sea," and of Clysma. All these data are directly
contradictory to preconceived theories: Pithom, Succoth, Heroöpolis,
Pihahiroth, and Clysma had all been hypothetically placed in totally
different positions. The identification of Pithom with Succoth gives us
the first absolutely certain point as yet established in the route of
the Exodus, and completely overthrows Dr. Brugsch's theory. It is now
certain that the Israelites passed along the valley of the Freshwater
Canal and not near the Mediterranean and Lake Serbonis. The first
definite geographical fact in connection with the sojourn in the Land of
Egypt has been established by the excavations at Pithom. The historical
identification of Rameses II. with Pharaoh the oppressor also results
from the monumental evidence. One short exploration has upset a hundred
theories and furnished a wonderful illustration of the historical
character of the Book of Exodus. The finding of Pithom (Succoth)
is, however, only the beginning, we hope, of a series of important
discoveries. When enough money has been collected for the proposed
exploration of Zoan (Tanis), results of the highest interest to students
alike of the Bible and of Egyptian antiquities may, with certainty, be
predicted.

The uppermost view shows a portion of the diggings; a workman is
bringing up a barrow-load of soil from one of the deep store chambers
which the Children of Israel built more than three thousand years ago.
In the foreground lie the fragments of a fallen granite statue, the head
and face of which are intact. The other illustration is taken from the
temple end of the excavations. The sculptured group of Rameses the Great
seated between divinities is one of a pair that adorned the entrance;
its companion and the sphinxes that guarded the pylon are at Ismailia.
Beyond this group, and a little to the left, is seen the great Stele of
Pithom, set up by Ptolemy Philadelphus and Arsinoë, and containing a
mass of important information in its long hieroglyphic inscriptions.
Behind this, and on either side, the massive brick walls of the store
chambers and the inclosing wall of the temple can be traced; while on
the right hand, in the middle distance, is a heap of limestone blocks,
already collected by Rameses II. for the completion or enlargement of
the temple. The excavations were photographed for M. Naville, by Herr
Emil Brugsch, of the Boulak Museum, and our illustrations are taken from
these photographs, supplemented by sketches.--_S.L.P., in Illustrated
London News_.

       *       *       *       *       *




THE MOABITE MANUSCRIPTS.


The surprises of archæology are magnificent and apparently
inexhaustible. It is continually bringing forth things new and old, and
often it happens that the newest are the oldest of all. Whether this
or the exact converse is the case in regard to the latest discovery of
Biblical archæology is a question not to be determined offhand; but the
interest and importance of the question can hardly be overrated. There
are now deposited in the British Museum fifteen leather slips, on the
forty folds of which are written portions of the Book of Deuteronomy
in a recension entirely different from that of the received text. The
character employed in the manuscript is similar to that of the famous
Moabite stone and of the Siloam inscription, and, therefore, the mere
palæographical indication should give the probable date of the slips as
the ninth century B. C., or sixteen centuries earlier than any other
clearly authenticated manuscript of any portion of the Old Testament.
The sheepskin slips are literally black with age, and are impregnated
with a faint odor as of funeral spices; the folds are from 6 to 7 inches
long and about 3½ inches wide, containing each about ten lines, written
only on one side.

So far as they have yet been deciphered, they exhibit two distinct
handwritings, though the same archaic character is used throughout.
In some cases the same passages of Deuteronomy occur in duplicate on
distinct slips, as though the fragments belonged to two contemporary
transcriptions made by different scribes from the same original text. At
first sight no writing whatever is perceptible; the surface seems to
be covered with an oily or glutinous substance, which so completely
obscures the writing beneath that a photograph of some of the
slips--which we have had an opportunity of examining side by side with
the slips themselves--exhibits no trace of the text. But when the
leather is moistened with spirits of wine the letters become momentarily
visible beneath the glossy surface.

These extraordinary fragments were brought to England by Mr. Shapira,
of Jerusalem, a well known bookseller and dealer in antiquities.
Mr. Shapira's name will be remembered in connection with certain
archæological problems which have been solved by some scholars in a
manner not altogether creditable to his sagacity.

The Moabite pottery which reached Europe through Mr. Shapira's agency
and is deposited in the Museum at Berlin is now commonly regarded as a
modern forgery; but of this forgery, if it be one, it is asserted that
Mr. Shapira was the dupe and not the accomplice. The leathern fragments
now produced by Mr. Shapira were, as he alleges, obtained by him from
certain Arabs near Dibon, the neighborhood where the Moabite stone was
discovered. The agent employed by him in their purchase was an Arab
"who would steal his mother-in-law for a few piastres," and who would
probably be even less scrupulous about a few blackened slips of ancient
or modern sheepskin. The value placed by Mr. Shapira on the fragments
is, however, a cool million sterling, and at this price they are offered
to the British Museum, where they have been temporarily deposited for
examination.

Dr. Ginsburg, the well-known Semitic scholar--whose receipt of a grant
of £500 from the Prime Minister toward the production of his important
work on the "Massorah" we announced with much satisfaction yesterday--is
now busily engaged in deciphering the contents of the fragments and
examining their genuineness. On this latter question we refrain from
pronouncing an opinion. When Dr. Ginsburg's report appears, we shall be
able to judge whether these extraordinary fragments are really 2,500
years old, or have been compiled within the last few years.

No complete account of the contents of the fragments can yet be given.
To decipher them is a work of time and of infinite patience and skill,
as will readily be inferred from the account we have given above of the
appearance and condition of the slips. But enough has been deciphered to
show that the text employed in them exhibits discrepancies of the most
remarkable and important character as compared with that of the received
version of the Mosaic books.

In the first verse of the ninth chapter of Deuteronomy, where the
received version reads, "Thou art to pass over Jordan this day, to go in
to possess nations greater and mightier than thyself," the corresponding
passage of the fragments substitutes the plural for the singular, "Ye"
for '"Thou," while for "_g'dôlîm_," the word translated "greater," it
reads "_rabbîm_." But a far more complete idea of the variations of text
and signification may be obtained from a comparison of the text of the
Decalogue as it appears in the received version in the sixth chapter of
Deuteronomy with that contained in the fragments so far as they have yet
been deciphered. The version of the fragments, literally rendered, runs
as follows:

"I am God, thy God, which liberated thee from the land of Egypt, from
the house of bondage. Ye shall have no other gods. Ye shall not make to
yourselves any graven image, nor any likeness that is in heaven above or
that is in the earth beneath, or that is in the waters under the earth.
Ye shall not bow down to them nor serve them. I am God, your God.
Sanctify ... in six days I have made the heaven and the earth, and all
that is therein, and rested on the seventh day, therefore rest thou
also, thou and thy cattle and all that thou hast: I am God, thy God.
Honor thy father and thy mother ...: I am God, thy God. Thou shall not
kill the person of thy brother: I am God, thy God. Thou shalt not commit
adultery with the wife of thy neighbor: I am God, thy God. Thou shalt
not steal the property of thy brother: I am God, thy God. Thou shalt not
swear by my name falsely, for I visit the iniquity of the fathers upon
the children unto the third and fourth generation of those who take
my name in vain: I am God, thy God. Thou shalt not bear false witness
against thy brother: I am God, thy God. Thou shalt not covet the wife
... or his manservant, or his maidservant, or anything that is his: I am
God, thy God. Thou shalt not hate thy brother in thy heart: I am God,
thy God. These ten words (or commandments) God spake."

Several points may be noted in this version. The singular refrain "I
am God, thy God"--which does not appear at all in the received
version--occurs ten times, being, as it were, a solemn ratification of
the Divine sanction given at the end of each separate precept. If this
be so, the first two commandments, as they are commonly reckoned, are
here fused into one, and the tenth place is taken by a commandment which
does not appear in the received version of the Decalogue.

It will further be observed that the distinctive Jewish name for the
Almighty, "Jehovah," or "the Lord," does not appear at all, the familiar
phrase of the received version, "the Lord thy God," being replaced
throughout by "God, thy God."

On the many variations in arrangement and detail we need not dwell;
they speak for themselves. But we have quoted enough to show that these
fragments present problems of the utmost importance and interest both to
criticism and exegesis, unless, indeed, they are to be regarded as
the ingenious fabrications of some Oriental Ireland, who, knowing the
interest felt by scholars in variations of the Sacred Text, has set
himself, with infinite pains and skill, to forestall a growing demand.
Until this preliminary question is resolved to the satisfaction of all
competent scholars, no further questions need be raised. In any case
the _primá facie_ presumption must be held to be enormously against
the genuineness of the fragments. Such a presumption rests on the
improbability of finding manuscripts older by at least sixteen centuries
than any extant manuscripts of the same text, on the comparative ease
with which such fragments can be forged, and on the powerful motives
to such forgery attested by the price placed by Mr. Shapira on his
property.

All that we know of the _provenance_ of the fragments is that Mr.
Shapira obtained them from an Arab of doubtful character; and that
Arabs of doubtful character have driven a splendid trade in Moabite
antiquities ever since the discovery of the Moabite stone. On the other
hand, the forger, if forgery there be, is assuredly no clumsy and
ignorant bungler, as the makers of the Moabite pottery were confidently
alleged to be by those who disputed its genuineness. It is, of course,
part of his craft, and not, perhaps, much more than the 'prentice part,
to give to the sheepskins on which the text is inscribed an appearance
of immemorial antiquity. But a good deal more than the skill required to
make a new sheepskin look like an old one has gone to the production of
Mr. Shapira's fragments. If they are forged, the fabricator must have
known what scholars would be likely to expect in genuine fragments,
and have set himself to fulfill their expectations. In these days of
scientific palæography and minute textual scholarship no forger of
ancient manuscripts could hope to take in scholars unless he were a
scholar himself. Variations of text would be looked for as a matter of
course; palæographical accuracy would be exacted to the minutest turn
of a letter. Now, to vary a text so as to furnish a different recension
without betraying ignorance or solecism requires scholarship of no mean
order, while it is very far from an easy thing to write currently in an
archaic and unfamiliar character in such a manner as to deceive experts
in palæography. But the fabricator of these fragments, if fabricated
they are, has attempted and accomplished a good deal more than this.
He has in some cases produced two identical texts written in different
hands, both preserving unimpaired the archaic character of the letters.
This implies either the employment of two scribes or else an almost
incredible skill in the single scribe employed, and in either case
it doubles the probability of detection. If, moreover, the supposed
fabricator is also himself the scribe, it is evident that he is not only
a very ingenious artist, but also a very accomplished scholar, and one
can only regret that he has engaged in an industry which has placed him
at the mercy of an Arab who would steal his mother-in-law for a few
piastres, and is likely, therefore, to enrich no one but Mr. Shapira. We
should expect to find, however, that his extraordinary ingenuity has at
some point or another overreached itself. Familiar as he must be with
the labors of modern Biblical critics--for otherwise he would hardly
have ventured to impose upon them--it would be strange if he were not
betrayed into some more or less suspicious coincidences with them. In
any case, the problem presented by the fragments is one of profound
interest, and the whole world of letters will resound with the
controversy they are certain to excite.--_London Times_.

       *       *       *       *       *

[Illustration: SPECIMENS OF OLD KNOCKING DEVICES FOR DOORS.--_From the
Building News_.]

       *       *       *       *       *




SHIPPING OSTRICHES FROM CAPE TOWN TO AUSTRALIA.


Since the failure last August of the Cape Commercial Bank there has been
much depression in South Africa. Ostrich farming, in common with
other enterprises, has suffered. Before the crisis a pair of breeding
ostriches have been sold for 350 l., now they would not realize 50 l.

The resolution of the Government of South Australia to encourage ostrich
breeding came in very opportunely for the Cape dealers, and one or two
cargoes of birds have been shipped for Adelaide. The climate of the two
colonies is very similar, and the locality selected for the imported
birds (the Musgrave Ranges) resembles in dryness and temperature their
native _habitat_.

The first sketch opposite represents the ostriches bidding farewell
to their South African home. "The dear old farm where we were reared,
good-by!"

One of the boxes, while being slung from the cart to the hold, got into
a slanting position. This frightened one of the two inmates, a fine
cock. He kicked so hard that he burst open the door of his cage, which
was, of course, instantly lowered on deck. Fortunately there was there
a gentleman who understood how to handle ostriches. He instantly seized
him before he could do himself or the bystanders any injury, and after
a brief struggle prevailed on him to re-enter his box. When released in
the hold he became quite quiet, and ate his first meal on board ship
with a relish.

After being taken out of their boxes the birds are allowed to take a
little exercise just to make themselves at home, and are then arranged
in wooden kraals, of which there are two hundred on board the vessel.
The ostriches are induced to move from one place to another by catching
hold of their bodies, and using a little gentle force.

The last sketch represents their first meal on board after a fast of
thirty hours. Apple melons were chopped up for them by their "steward,"
who was to accompany them to Australia. It was curious to see a bird
swallow a great lump and then to watch the lump working slowly down
the animal's long neck. On the voyage they would be fed with maize or
mealies, onions, apple melons, and barley. They require very little
water; however, there were five large iron tanks on board in case they
would feel thirsty. Our engravings are from sketches by Mr. Dennis
Edwards, of Hoff Street, Capetown,

[Illustration: SHIPPING OSTRICHES FROM CAPE TOWN TO AUSTRALIA.

1. Ostriches on the South African Farm Where They Were Reared.--2.
Attempted Escape and Recapture of an Ostrich on Board Ship.--3. Lowering
the Birds Into the Hold.--4.A Queer Dinner Party--Ostriches Eating Apple
Melons.]

       *       *       *       *       *




A NEW WEATHERCOCK.


An ordinary weathercock provided with datum points may, in the majority
of cases, suffice for the observation of the wind during the day;
but recourse has to be had to different means to obtain an automatic
transmission of the indications of the vane to the inside of a building.
The different systems employed for such a purpose consist of gearings,
or are accompanied by a friction that notably diminishes the
sensitiveness of the apparatus, especially when the rod has to traverse
several stories. Mr. Emile Richard, inspector of the Versailles
waterworks, has just devised an ingenious system which, while
considerably reducing the weight of the movable part, allows the
weathercock to preserve all its sensitiveness. This apparatus consists
of two principal parts--one fixed and the other movable. The stationary
part is designated in the accompanying figure by the letters A and B and
by cross-hatchings. This forms the rod or support. An iron tube, T, with
clamps, P, at its lower extremity forms the base of the apparatus, and
is hidden, after the mounting of the apparatus, by the ornamental zinc
covering, Z. The upper part of the tube carries a shoulder-piece,
upon which rests a bronze platform, E, and which is slightly inclined
outwardly to prevent the accumulation of water on it. Over the platform
there move three crystal balls, which are held and guided by a
horizontal disk movable around the stationary tube.

The movable portion, designed to receive the action of the wind and to
indicate its direction, is designated by the letters C D and coarse
lines. It consists of (1) a zinc tube, K, provided at intervals with
copper rings, and entering the rod, A B, which serves as a guide for it;
(2) of a bronze disk covered by an external ornament, O, fixed to the
tube and resting on the balls; (3) of the vane, G, properly so called;
and (4) of the cap, C, provided with bayonet catch, crowning the tube
and covering the point of attachment of the wire of transmission.
This latter consists of a simple brass or galvanized iron wire, f f,
perfectly taut, and made fast in the top of the tube. After traversing
as many stories as necessary this wire terminates, in the interior of
the room where the observations are made, in a copper rod to which is
fastened a horizontal arrow, F. The wire traverses the floorings through
small zinc tubes; and, in the rooms through which it passes, it is
protected by iron tubes. To the ceiling of the observing room there is
affixed a wind-rose, R, on which the arrow reproduces all the motions of
the vane.

[Illustration: RICHARD'S WEATHERCOCK.]

This apparatus is now in operation in the different stations that the
Versailles waterworks has established near the reservoirs of the plateau
of Trappes, and it is also installed in several primary normal schools,
where it is giving very good results.--_La Nature_.

       *       *       *       *       *




CHARRED CLOVER.


A correspondent of the _Ohio Farmer_ reports an experiment in curing
clover, showing how he just missed breeding fire in his barn, and
illustrating the importance of ventilating hay mows:

In 1861 I used a horse fork for the first time. The haying season was
not a bright one, and our clover was drawn a little greener than usual,
and went into the mow in large and compact forkfuls. The result was
intense heating, and consequently very rapid evaporation and sweating of
the mow. On a bay holding ordinarily twenty tons we put at least thirty
tons, as every load at the top seemed to make room for another. The barn
was rather open, which allowed quite free evaporation on all sides as
well as at the top. The result was that I had very bright and excellent
hay at the bottom, top, and sides of that mow, but severals tons in the
center were as completely charred as though burned in a coal pit. What
prevented combustion has always been a mystery to me. Since that escape
from a conflagration, I have not deemed it prudent to put clover in so
green as to cause intense heating, or to fill a mow too rapidly. If we
haul six loads per day to one mow, weighing thirty hundred each, which
will shrink during the sweating process to one ton each, we have three
tons of water to be thrown off by evaporation.

If we continue to put on six loads per day until the mow is full, the
principal part of that moisture must rise through the entire mass. To
relieve the hay of moisture, I deem it best to have several places of
storage, and change daily or semi-daily from one to the other, thus
giving time for a share of the moisture to pass off. To facilitate this
evaporation and prevent the hay from reabsorbing it and becoming musty,
the best of ventilation is necessary. Ventilation above a clover mow is
as necessary as it is above a sugar or fruit evaporator. If there is
not open space and draught sufficient to carry away the moisture, it is
returned to the mow, and mould is the inevitable result. No ordinary
amount of drying will prevent hay from becoming musty if ventilation is
shut off during the sweating process. If a hole is cut through the floor
at the bottom of the mow near the center and under a ventilator in the
roof and a barrel placed over it and drawn up as the hay is mowed in,
thus leaving a hole from bottom to top, evaporation will be facilitated
and the quality of the hay improved. Salt thrown on, as the clover is
put in, to the amount of two or three quarts to the ton, will make it a
relish with stock.

       *       *       *       *       *




THE QUEEN VICTORIA CENTURY PLANT.

(_Agave victoriæ-reginæ_.)


This beautiful Agave is now in blossom in the garden here, and I am
happy to be able to send you photographs of it. This is the first time
it has ever blossomed in cultivation, and it has never been seen in
flower in a wild state. It is a mature native-grown specimen, dense in
habit, and perfectly semi-spherical in form, and the leaves are arranged
in spiral fashion with as much regularity as those of a screw pine. The
circumference of the plant is 5 ft. 1 in., and it has 268 leaves. Its
flower-stem appeared about the middle of June, grew rather fast till it
was 7 ft. high, then rather slowly till it reached its full development.
The scape is now 10 ft. 4 in. high above the plant, 6½ in. in
circumference at the base, or 5¼ in. at a foot above the base; from
there it tapers very gradually till near the apex. The flower-spike is
exceedingly dense, and 5 ft. 8 in. long; the lower or naked portion, 4
ft. 8 in. long, is prominently marked by abortive flower buds, with,
near the base, some bristle-like scales 3½ in. to 4 in. long. The
flowers are regularly arranged in parcels of three, all the three being
equal in size and opening together; they are greenish white in color, 1½
in. long, or, including the stamens, some 2¾ in. to 3 in. long.

[Illustration: AGAVE VICTORIÆ-REGINÆ.]

The first flowers opened on August 3, and they have continued to open
in succession, a belt about 3 in. wide opening each day. They remain in
good condition for two days; on the third day the stamens wilt and drop
down, but the pistil remains erect till the fourth day. On the first day
of opening the pistil is not so long as the stamens by ¾ in.; on the
second it has grown to be as long as the stamens, but it is not in
condition to receive the pollen till after noon of the second day.
Although the flowers on some eighteen inches of the spike have already
blossomed, none of the ovaries have been fertilized; they are dropping
off, but I am rather sanguine regarding those about the middle of the
spike. So great is the superfluity of nectar contained in the flowers,
that on the afternoon of the second day it often drops from the cups,
and the least shake to the scape brings it down in a shower. The main
beauty of the inflorescence consists in the dense bottle-brush-like mass
of bright yellow anthers. This plant, together with several smaller
ones, was contributed to this garden by Dr. Edward Palmer, who collected
them in their native wilds--the mountains of Northern Mexico--some three
years ago. He found them growing in a limited and rather inaccessible
locality in gravelly and rocky soil some miles from Monterey. In
addition to those he sent here he also sent a quantity to the garden of
the Agricultural Department at Washington, and some to Dr. Engelmann,
the eminent botanist at St. Louis. To Dr. Engelmann he also sent a piece
of an old flower stem and some dried capsules which he found upon an
old plant, and it was from these specimens in 1880 that the doctor
was enabled to describe for the first time the inflorescence of this
Agave.--_The Garden_.

       *       *       *       *       *




ON THE CONSTITUTION OF THE NATURAL FATS.

By J. ALFRED WANKLYN and WILLIAM FOX.


In the course of an investigation in which we are at present engaged we
have arrived at some results which appear to us to be very interesting.
We find that the generally received view that the fats are ethers of
glycerin is partially correct, and that instances of a different kind of
structure occur among the natural oils and fats.

Ethers of iso-glycerin, or of homologues of iso-glycerin, appear to
occur. Iso-glycerin has this structure:

  C(OH)_{2}
  CH
  CH_{3}

It exists in its ethers, but cannot be isolated, and should be resolved
into:

  COOH + H_{2}O
  CH_{2}
  CH_{3}

Ethers of iso-glycerin, or ethers of homologues of iso-glycerin, yield
no glycerin when saponified.--_Chemical News_.

       *       *       *       *       *

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