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[Illustration]




SCIENTIFIC AMERICAN SUPPLEMENT NO. 363




NEW YORK, DECEMBER 16, 1882

Scientific American Supplement. Vol. XIV, No. 363.

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.    ENGINEERING AND MECHANICS.--The New York Canals.--
      Their history, dimensions, and commercial influence

      Cottrau's Locomotive for Ascending Steep Grades.--1 figure

      Bachmann's Steam Drier--3 figures

      H. S. Parmelee's Patent Automatic sprinkler.--2 figures

      Instrument for Drawing Converging Straight Lines.--10 figures

      Feed Water Heater and Purifier. By GEO. S. STRONG.--2 figures

      Paper Making "Down East."

      Goulier's Tube Gauge.--1 figure.-Plan and longitudinal and
      transverse sections

      Soldering Without an Iron

      Working Copper Ores at Spenceville

II.   TECHNOLOGY AND CHEMISTRY-New Method of Detecting
      Dyes on Yarns and Tissues. By JULES JOFFRE.--Reagents.--Red
      colors.--Violet colors

      Chevalet's Condenso-purifier for Gas.--2 figures.--Elevation and
      plan

      Artificial Ivory

      Creosote Impurities. By Prof P. W. BEDFORD

III.  ELECTRICITY. ETC.--Sir William Thomson's Pile--2 figures

      Siemens' Telemeter.--1 figure.--Siemens electric telemeter

      Physics Without Apparatus.--Experiment in static electricity.--
      1 figure

      The Cascade Battery. By F. HIGGINS.--1 figure

      Perfectly Lovely Philosophy

IV.   ASTRONOMY, ETC.--The Comet as seen from the Pyramids
      near Cairo, Egypt.--1 figure

      Sunlight and skylight at High Altitudes.--Influence of the
      atmosphere upon the solar spectrum.--Observations of Capt.
      Abney and Professor Langley.--2 figures

      How to Establish a True Meridian

V.    MINERALOGY.--The Mineralogical Localities in and Around
      New York City, and the Minerals Occurring Therein. By NELSON
      H. DAKTON. Part III.--Hoboken minerals.--Magnesite.--Dolomite.
      --Brucite.--Aragonite.--Serpentine.--Chromic iron--Datholite.
      --Pectolite.--Feldspar.--Copper mines, Arlington, N.J.-Green
      malachite.--Red oxide of copper.--Copper glance.--Erubescite

VI.   ENTOMOLOGY.--The Buckeye Leaf Stem Borer

      Defoliation of Oak Trees by _Dryocampa senatoria_ in Perry
      County, Pa.

      Efficacy of Chalcid Egg Parasites

      On the Biology of _Gonatopis Pilosus_, Thoms

      Species of Otiorhynchadae Injurious to Cultivated Plants

VII.  ART, ARCHITECTURE, ETC.--Monteverde's Statue of Architecture.
      --Full page illustration, _Lit Architectura_.
      By JULI MONTEVERDE

      Design for a Gardener's Cottage.--1 figure

VIII. HYGIENE AND MEDICINE.--Remedy for Sick Headache

IX.   ORNITHOLOGY.--Sparrows in the United States.--Effects of
      acclimation, etc.

X.    MISCELLANEOUS.--James Prescott Joule, with Portrait.--A
      sketch of the life and investigations of the discoverer of the
      mechanical equivalent of heat. By J. T. BOTTOMLEY

      The Proposed Dutch International Colonial and General Export
      Exhibition.--1 figure.--Plan of the Amsterdam Exhibition

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THE COMET FROM THE PYRAMIDS, CAIRO


Some centuries ago, the appearance of so large a comet as is now
interesting the astronomical world, almost contemporaneously with our
victory in Egypt, would have been looked upon as an omen of great
portent, and it is a curious coincidence that the first glimpse Sir
Garnet Wolseley had of this erratic luminary was when standing, on
the eventful morning of September 13, 1882, watch in hand, before the
intrenchments of Tel-el-Kebir, waiting to give the word to advance.
As may be seen in our sketch, the comet is seen in Egypt in all its
magnificence, and the sight in the early morning from the pyramids (our
sketch was taken at 4 A.M.) is described as unusually grand.--_London
Graphic_.

[Illustration: THE COMET AS SEEN FROM THE GREAT PYRAMIDS, NEAR CAIRO,
EGYPT.]

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[NATURE.]




JAMES PRESCOTT JOULE.


James Prescott Joule was born at Salford, on Christmas Eve of the year
1818. His father and his grandfather before him were brewers, and the
business, in due course, descended to Mr. Joule and his elder brother,
and by them was carried on with success till it was sold, in 1854.
Mr. Joule's grandfather came from Elton, in Derbyshire, settled near
Manchester, where he founded the business, and died at the age of
fifty-four, in 1799. His father, one of a numerous family, married a
daughter of John Prescott of Wigan. They had five children, of
whom James Prescott Joule was the second, and of whom three were
sons--Benjamin, the eldest, James, and John--and two daughters--Alice
and Mary. Mr. Joule's mother died in 1836 at the age of forty-eight; and
his father, who was an invalid for many years before his death, died at
the age of seventy-four, in the year 1858.

Young Joule was a delicate child, and was not sent to school. His early
education was commenced by his mother's half sister, and was carried
on at his father's house, Broomhill, Pendlebury, by tutors till he was
about fifteen years of age. At fifteen he commenced working in the
brewery, which, as his father's health declined, fell entirely into the
hands of his brother Benjamin and himself.

Mr. Joule obtained his first instruction in physical science from
Dalton, to whom his father sent the two brothers to learn chemistry.
Dalton, one of the most distinguished chemists of any age or country,
was then President of the Manchester Literary and Philosophical Society,
and lived and received pupils in the rooms of the Society's house. Many
of his most important memoirs were communicated to the Society, whose
_Transactions_ are likewise enriched by a large number of communications
from his distinguished pupil. Dalton's instruction to the two young men
commenced with arithmetic, algebra, and geometry. He then taught them
natural philosophy out of Cavallo's text-book, and afterward, but only
for a short time before his health gave way, in 1837, chemistry from his
own "New System of Chemical Philosophy." "Profound, patient, intuitive,"
his teaching must have had great influence on his pupils. We find Mr.
Joule early at work on the molecular constitution of gases, following in
the footsteps of his illustrious master, whose own investigations on the
constitution of mixed gases, and on the behavior of vapors and gases
under heat, were among the most important of his day, and whose
brilliant discovery of the atomic theory revolutionized the science of
chemistry and placed him at the head of the philosophical chemists of
Europe.

[Illustration: JAMES PRESCOTT JOULE.]

Under Dalton, Mr. Joule first became acquainted with physical apparatus;
and the interest excited in his mind very soon began to produce fruit.
Almost immediately he commenced experimenting on his own account.
Obtaining a room in his father's house for the purpose, he began by
constructing a cylinder electric machine in a very primitive way. A
glass tube served for the cylinder; a poker hung up by silk threads, as
in the very oldest forms of electric machine, was the prime conductor;
and for a Leyden jar he went back to the old historical jar of Cunaeus,
and used a bottle half filled with water, standing in an outer vessel,
which contained water also.

Enlarging his stock of apparatus, chiefly by the work of his own hands,
he soon entered the ranks as an investigator, and original papers
followed each other in quick succession. The Royal Society list now
contains, the titles of ninety-seven papers due to Joule, exclusive of
over twenty very important papers detailing researches undertaken by him
conjointly with Thomson, with Lyon Playfair, and with Scoresby.

Mr. Joule's first investigations were in the field of magnetism. In
1838, at the age of nineteen, he constructed an electro-magnetic engine,
which he described in Sturgeon's "Annals of Electricity" for January
of that year. In the same year, and in the three years following, he
constructed other electro-magnetic machines and electro-magnets of novel
forms; and experimenting with the new apparatus, he obtained results
of great importance in the theory of electro-magnetism. In 1840 he
discovered and determined the value of the limit to the magnetization
communicable to soft iron by the electric current; showing for the case
of an electro-magnet supporting weight, that when the exciting current
is made stronger and stronger, the sustaining power tends to a certain
definite limit, which, according to his estimate, amounts to about
140 lb. per square inch of either of the attracting surfaces.
He investigated the relative values of solid iron cores for the
electro-magnetic machine, as compared with bundles of iron wire; and,
applying the principles which he had discovered, he proceeded to the
construction of electro-magnets of much greater lifting power than any
previously made, while he studied also the methods of modifying the
distribution of the force in the magnetic field.

In commencing these investigations he was met at the very outset, as he
tells us, with "the difficulty, if not impossibility, of understanding
experiments and comparing them with one another, which arises in general
from incomplete descriptions of apparatus, and from the arbitrary and
vague numbers which are used to characterize electric currents. Such a
practice," he says, "might be tolerated in the infancy of science; but
in its present state of advancement greater precision and propriety are
imperatively demanded. I have therefore determined," he continues,
"for my own part to abandon my old quantity numbers, and to express my
results on the basis of a unit which shall be at once scientific and
convenient."

The discovery by Faraday of the law of electro-chemical equivalents
had induced him to propose the voltameter as a measurer of electric
currents, but the system proposed had not been used in the researches
of any electrician, not excepting those of Faraday himself. Joule,
realizing for the first time the importance of having a system of
electric measurement which would make experimental results obtained
at different times and under various circumstances comparable among
themselves, and perceiving at the same time the advantages of a system
of electric measurement dependent on, or at any rate comparable with,
the chemical action producing the electric current, adopted as unit
quantity of electricity the quantity required to decompose nine grains
of water, 9 being the atomic weight of water, according to the chemical
nomenclature then in use.

He had already made and described very important improvements in the
construction of galvanometers, and he graduated his tangent galvanometer
to correspond with the system of electric measurement he had adopted.
The electric currents used in his experiments were thenceforth measured
on the new system; and the numbers given in Joule's papers from 1840
downward are easily reducible to the modern absolute system of electric
measurements, in the construction and general introduction of which
he himself took so prominent a part. It was in 1840, also, that after
experimenting on improvements in voltaic apparatus, he turned his
attention to "the heat evolved by metallic conductors of electricity and
in the cells of a battery during electrolysis." In this paper, and those
following it in 1841 and 1842, he laid the foundation of a new province
in physical science-electric and chemical thermodynamics-then totally
unknown, but now wonderfully familiar, even to the roughest common sense
practical electrician. With regard to the heat evolved by a metallic
conductor carrying an electric current, he established what was already
supposed to be the law, namely, that "the quantity of heat evolved by
it [in a given time] is always proportional to the resistance which it
presents, whatever may be the length, thickness, shape, or kind of the
metallic conductor," while he obtained the law, then unknown, that
the heat evolved is proportional to the _square_ of the quantity of
electricity passing in a given time. Corresponding laws were established
for the heat evolved by the current passing in the electrolytic cell,
and likewise for the heat developed in the cells of the battery itself.

In the year 1840 he was already speculating on the transformation of
chemical energy into heat. In the paper last referred to and in a short
abstract in the _Proceedings of the Royal Society_, December, 1840, he
points out that the heat generated in a wire conveying a current of
electricity is a part of the heat of chemical combination of the
materials used in the voltaic cell, and that the remainder, not the
whole heat of combination, is evolved within the cell in which the
chemical action takes place. In papers given in 1841 and 1842, he pushes
his investigations further, and shows that the sum of the heat produced
in all parts of the circuit during voltaic action is proportional to the
chemical action that goes on in the voltaic pile, and again, that the
quantities of heat which are evolved by the combustion of equivalents
of bodies are proportional to the intensities of their affinities for
oxygen. Having proceeded thus far, he carried on the same train of
reasoning and experiment till he was able to announce in January, 1843,
that the magneto-electric machine enables us to _convert mechanical
power into heat_. Most of his spare time in the early part of the year
1843 was devoted to making experiments necessary for the discovery of
the laws of the development of heat by magneto-electricity, and for the
definite determination of the mechanical value of heat.

At the meeting of the British Association at Cork, on August 21, 1843,
he read his paper "On the Calorific Effects of Magneto-Electricity,
and on the Mechanical Value of Heat." The paper gives an account of an
admirable series of experiments, proving that _heat is generated_ (not
merely _transferred_ from some source) by the magneto-electric machine.
The investigation was pushed on for the purpose of finding whether a
_constant ratio exists between the heat generated and the mechanical
power_ used in its production. As the result of one set of
magneto-electric experiments, he finds 838 foot pounds to be the
mechanical equivalent of the quantity of heat capable of increasing the
temperature of one pound of water by one degree of Fahrenheit's scale.
The paper is dated Broomhill, July, 1843, but a postscript, dated
August, 1843, contains the following sentences:

"We shall be obliged to admit that Count Rumford was right in
attributing the heat evolved by boring cannon to friction, and not (in
any considerable degree) to any change in the capacity of the metal. I
have lately proved experimentally that _heat is evolved by the passage
of water through narrow tubes_. My apparatus consisted of a piston
perforated by a number of small holes, working in a cylindrical glass
jar containing about 7 lb. of water. I thus obtained one degree of heat
per pound of water from a mechanical force capable of raising about 770
lb. to the height of one foot, a result which will be allowed to be very
strongly confirmatory of our previous deductions. I shall lose no time
in repeating and extending these experiments, being satisfied that the
grand agents of nature are, by the Creator's fiat, _indestructible_, and
that wherever mechanical force is expended, an exact equivalent of heat
is _always_ obtained."

This was the first determination of the dynamical equivalent of heat.
Other naturalists and experimenters about the same time were attempting
to compare the quantity of heat produced under certain circumstances
with the quantity of work expended in producing it; and results and
deductions (some of them very remarkable) were given by Séguin (1839),
Mayer (1842), Colding (1843), founded partly on experiment, and partly
on a kind of metaphysical reasoning. It was Joule, however, who first
definitely proposed the problem of determining the relation between heat
produced and work done in any mechanical action, and solved the problem
directly.

It is not to be supposed that Joule's discovery and the results of his
investigation met with immediate attention or with ready acquiescence.
The problem occupied him almost continuously for many years; and in 1878
he gives in the _Philosophical Transactions_ the results of a fresh
determination, according to which the quantity of work required to be
expended in order to raise the temperature of one pound of water weighed
in vacuum from 60° to 61° Fahr., is 772.55 foot pounds of work at the
sea level and in the latitude of Greenwich. His results of 1849 and 1878
agree in a striking manner with those obtained by Hirn and with those
derived from an elaborate series of experiments carried out by Prof.
Rowland, at the expense of the Government of the United States.

His experiments subsequent to 1843 on the dynamical equivalent of
heat must be mentioned briefly. In that year his father removed from
Pendlebury to Oak Field, Whalley Range, on the south side of Manchester,
and built for his son a convenient laboratory near to the house. It was
at this time that he felt the pressing need of accurate thermometers;
and while Regnault was doing the same thing in France, Mr. Joule
produced, with the assistance of Mr. Dancer, instrument maker, of
Manchester, the first English thermometers possessing such accuracy
as the mercury-in-glass thermometer is capable of. Some of them were
forwarded to Prof. Graham and to Prof. Lyon Playfair; and the production
of these instruments was in itself a most important contribution to
scientific equipment.

As the direct experiment of friction of a fluid is dependent on no
hypothesis, and appears to be wholly unexceptionable, it was used by Mr.
Joule repeatedly in modified forms. The stirring of mercury, of oil,
and of water with a paddle, which was turned by a falling weight,
was compared, and solid friction, the friction of iron on iron under
mercury, was tried; but the simple stirring of water seemed preferable
to any, and was employed in all his later determinations.

In 1847 Mr. Joule was married to Amelia, daughter of Mr. John Grimes,
Comptroller of Customs, Liverpool. His wife died early (1854), leaving
him one son and one daughter.

The meeting of the British Association at Oxford, in this year, proved
an interesting and important one. Here Joule read a fresh paper "On the
Mechanical Equivalent of Heat." Of this meeting Sir William Thomson
writes as follows to the author of this notice:

"I made Joule's acquaintance at the Oxford meeting, and it quickly
ripened into a lifelong friendship.

"I heard his paper read in the section, and felt strongly impelled at
first to rise and say that it must be wrong, because the true mechanical
value of heat given, suppose in warm water, must, for small differences
of temperature, be proportional to the square of its quantity. I knew
from Carnot that this _must_ be true (and it _is_ true; only now I call
it 'motivity,' to avoid clashing with Joule's 'mechanical value'). But
as I listened on and on, I saw that (though Carnot had vitally important
truth, not to be abandoned) Joule had certainly a great truth and a
great discovery, and a most important measurement to bring forward. So,
instead of rising, with my objection, to the meeting, I waited till it
was over, and said my say to Joule himself, at the end of the meeting.
This made my first introduction to him. After that I had a long talk
over the whole matter at one of the _conversaziones_ of the Association,
and we became fast friends from thenceforward. However, he did not tell
me he was to be married in a week or so; but about a fortnight later I
was walking down from Chamounix to commence the tour of Mont Blanc, and
whom should I meet walking up but Joule, with a long thermometer in his
hand, and a carriage with a lady in it not far off. He told me he had
been married since we had parted at Oxford! and he was going to try for
elevation of temperature in waterfalls. We trysted to meet a few days
later at Martigny, and look at the Cascade de Sallanches, to see if it
might answer. We found it too much broken into spray. His young wife, as
long as she lived, took complete interest in his scientific work, and
both she and he showed me the greatest kindness during my visits to them
in Manchester for our experiments on the thermal effects of fluid in
motion, which we commenced a few years later"

"Joule's paper at the Oxford meeting made a great sensation. Faraday was
there and was much struck with it, but did not enter fully into the new
views. It was many years after that before any of the scientific chiefs
began to give their adhesion. It was not long after, when Stokes told me
he was inclined to be a Joulite."

"Miller, or Graham, or both, were for years quite incredulous as to
Joule's results, because they all depended on fractions of a degree of
temperature--sometimes very small fractions. His boldness in making such
large conclusions from such very small observational effects is almost
as noteworthy and admirable as his skill in extorting accuracy from
them. I remember distinctly at the Royal Society, I think it was either
Graham or Miller, saying simply he did not believe Joule, because he had
nothing but hundredths of a degree to prove his case by."

The friendship formed between Joule and Thomson in 1847 grew rapidly.
A voluminous correspondence was kept up between them, and several
important researches were undertaken by the two friends in common. Their
first joint research was on the thermal effects experienced by air
rushing through small apertures The results of this investigation give
for the first time an experimental basis for the hypothesis assumed
without proof by Mayer as the foundation for an estimate of the
numerical relation between quantities of heat and mechanical work, and
they show that for permanent gases the hypothesis is very approximately
true. Subsequently, Joule and Thomson undertook more comprehensive
investigations on the thermal effects of fluids in motion, and on the
heat acquired by bodies moving rapidly through the air. They found the
heat generated by a body moving at one mile per second through the air
sufficient to account for its ignition. The phenomena of "shooting
stars" were explained by Mr. Joule in 1847 by the heat developed by
bodies rushing into our atmosphere.

It is impossible within the limits to which this sketch is necessarily
confined to speak in detail of the many researches undertaken by Mr.
Joule on various physical subjects. Even of the most interesting of
these a very brief notice must suffice for the present.

Molecular physics, as I have already remarked, early claimed his
attention. Various papers on electrolysis of liquids, and on the
constitution of gases, have been the result. A very interesting paper
on "Heat and the Constitution of Elastic Fluids" was read before
the Manchester Literary and Philosophical Society in 1848. In it he
developed Daniel Bernoulli's explanation of air pressure by the impact
of the molecules of the gas on the sides of the vessel which contains
it, and from very simple considerations he calculated the average
velocity of the particles requisite to produce ordinary atmospheric
pressure at different temperatures. The average velocity of the
particles of hydrogen at 32° F. he found to be 6,055 feet per second,
the velocities at various temperatures being proportional to the square
roots of the numbers which express those temperatures on the absolute
thermodynamic scale.

His contribution to the theory of the velocity of sound in air was
likewise of great importance, and is distinguished alike for the
acuteness of his explanations of the existing causes of error in the
work of previous experimenters, and for the accuracy, so far as
was required for the purpose in hand, of his own experiments. His
determination of the specific heat of air, pressure constant, and the
specific heat of air, volume constant, furnished the data necessary for
making Laplace's theoretical velocity agree with the velocity of sound
experimentally determined. On the other hand, he was able to account
for most puzzling discrepancies, which appeared in attempted direct
determinations of the differences between the two specific heats by
careful experimenters. He pointed out that in experiments in which air
was allowed to rush violently or _explode_ into a vacuum, there was a
source of loss of energy that no one had taken account of, namely,
in the sound produced by the explosion. Hence in the most careful
experiments, where the vacuum was made as perfect as possible, and the
explosion correspondingly the more violent, the results were actually
the worst. With his explanations, the theory of the subject was rendered
quite complete.

Space fails, or I should mention in detail Mr. Joule's experiments on
magnetism and electro-magnets, referred to at the commencement of this
sketch. He discovered the now celebrated change of dimensions produced
by the magnetization of soft iron by the current. The peculiar noise
which accompanies the magnetization of an iron bar by the current,
sometimes called the "magnetic tick," was thus explained.

Mr. Joule's improvements in galvanometers have already been incidentally
mentioned, and the construction by him of accurate thermometers has been
referred to. It should never be forgotten that _he first_ used small
enough needles in tangent galvanometers to practically annul error from
want of uniformity of the magnetic field. Of other improvements and
additions to philosophical instruments may be mentioned a thermometer,
unaffected by radiation, for measuring the temperature of the
atmosphere, an improved barometer, a mercurial vacuum pump, one of the
very first of the species which is now doing such valuable work, not
only in scientific laboratories, but in the manufacture of incandescent
electric lamps, and an apparatus for determining the earth's horizontal
magnetic force in absolute measure.

Here this imperfect sketch must close. My limits are already passed. Mr.
Joule has never been in any sense a public man; and, of those who know
his name as that of the discoverer who has given the experimental basis
for the grandest generalization in the whole of physical science, very
few have ever seen his face. Of his private character this is scarcely
the place to speak. Mr. Joule is still among us. May he long be spared
to work for that cause to which he has given his life with heart-whole
devotion that has never been excelled.

In June, 1878, he received a letter from the Earl of Beaconsfield
announcing to him that Her Majesty the Queen had been pleased to grant
him a pension of £200 per annum. This recognition of his labors by his
country was a subject of much gratification to Mr. Joule.

Mr. Joule received the Gold Royal Medal of the Royal Society in 1852,
the Copley Gold Medal of the Royal Society in 1870, and the Albert Medal
of the Society of Arts from the hand of the Prince of Wales in 1880.

J. T. BOTTOMLEY.

       *       *       *       *       *




THE NEW YORK CANALS.


The recent adoption of the constitutional amendment abolishing tolls on
the canals of New York State has revived interest in these water ways.
The overwhelming majority by which the measure was passed shows, says
the _Glassware Reporter_, that the people are willing to bear the cost
of their management by defraying from the public treasury all expenses
incident to their operation. That the abolition of the toll system will
be a great gain to the State seems to be admitted by nearly everybody,
and the measure met with but little opposition except from the railroad
corporations and their supporters.

At as early a date as the close of the Revolutionary War, Mr. Morris had
suggested the union of the great lakes with the Hudson River, and in
1812 he again advocated it. De Witt Clinton, of New York, one of the
most, valuable men of his day, took up the idea, and brought the leading
men of his State to lend him their support in pushing it. To dig a
canal all the way from Albany to Lake Erie was a pretty formidable
undertaking; the State of New York accordingly invited the Federal
government to assist in the enterprise.

The canal was as desirable on national grounds as on any other, but the
proposition met with a rebuff, and the Empire State then resolved to
build the canal herself. Surveyors were sent out to locate a line for
it, and on July 4, 1817, ground was broken for the canal by De Witt
Clinton, who was then Governor of the State.

The main line, from Albany, on the Hudson, to Buffalo, on Lake Erie,
measures 363 miles in length, and cost $7,143,789. The Champlain,
Oswego, Chemung, Cayuga, and Crooked Lake canals, and some others, join
the main line, and, including these branch lines, it measures 543 miles
in length, and cost upward of $11,500,000. This canal was originally 40
feet in breadth at the water line, 28 feet at the bottom, and 4 feet in
depth. Its dimensions proved too small for the extensive trade which it
had to support, and the depth of water was increased to 7 feet, and the
extreme breadth of the canal to 60 feet. There are 84 locks on the main
line. These locks, originally 90 feet in length and 15 in breadth, and
with an average lift of 8 feet 2 inches, have since been much enlarged.
The total rise and fall is 692 feet. The towpath is elevated 4 feet
above the level of the water, and is 10 feet in breadth. At Lockport the
canal descends 60 feet by means of 5 locks excavated in solid rock, and
afterward proceeds on a uniform level for a distance of 63 miles to the
Genesee River, over which it is carried on an aqueduct having 9 arches
of 50 feet span each. Eight and a half miles from this point it passes
over the Cayuga marsh, on an embankment 2 miles in length, and in some
places 70 feet in height. At Syracuse, the "long level" commences, which
extends for a distance of 69½ miles to Frankfort, without an intervening
lock. After leaving Frankfort, the canal crosses the river Mohawk, first
by an aqueduct 748 feet in length, supported on 16 piers, elevated 25
feet above the surface of the river, and afterward by another aqueduct
1,188 feet in length, and emerges into the Hudson at Albany.

This great work was finished in 1825, and its completion was the
occasion of great public rejoicing. The same year that the Erie Canal
was begun, ground was broken for a canal from Lake Champlain to the
Hudson, sixty-three miles in length. This work was completed in 1823.

The construction of these two water ways was attended with the most
interesting consequences. Even before they were completed their value
had become clearly apparent. Boats were placed upon the Erie Canal as
fast as the different levels were ready for use, and set to work in
active transportation. They were small affairs compared with those of
the present day, being about 50 or 60 tons burden, the modern canal boat
being 180 or 200 tons. Small as they were, they reduced the cost of
transportation immediately to one-tenth what it had been before. A ton
of freight by land from Buffalo to Albany cost at that time $100. When
the canal was open its entire length, the cost of freight fell from
fifteen to twenty-five dollars a ton, according to the class of article
carried; and the time of transit from 20 to 8 days, Wheat at that time
was worth only $33 a ton in western New York, and it did not pay to send
it by land to New York. When sent to market at all, it was floated down
the Susquehanna to Baltimore, as being the cheapest and best market.
The canal changed that. It now became possible to send to market a wide
variety of agricultural produce--fruit, grain, vegetables, etc.--which,
before the canal was built, either had no value at all, or which could
be disposed of to no good advantage. It is claimed by the original
promoters of the Erie Canal, who lived to see its beneficial effects
experienced by the people of the country, that their work, costing less
than $8.000,000 and paying its whole cost of construction in a very
few years, added $100,000,000 to the value of the farms of New York by
opening up good and ready markets for their products. The canal had
another result. It made New York city the commercial metropolis of the
country. An old letter, written by a resident of Newport, R. I., in that
age, has lately been discovered, which speaks of New York city, and
says: "If we do not look out, New York will get ahead of us." Newport
was then one of the principal seaports of the country; it had once been
the first. New York city certainly did "get ahead of us" after the Erie
Canal was built. It got ahead of every other commercial city on the
coast. Freight, which had previously gone overland from Ohio and the
West to Pittsburg, and thence to Philadelphia, costing $120 a ton
between the two cities named, now went to New York by way of the Hudson
River and the Erie Canal and the lakes. Manufactures and groceries
returned to the West by the same route, and New York became a
flourishing and growing emporium immediately. The Erie Canal was
enlarged in 1835, so as to permit the passage of boats of 100 tons
burden, and the result was a still further reduction of the cost of
freighting, expansion of traffic, and an increase of the general
benefits conferred by the canal. The Champlain Canal had an effect upon
the farms and towns lying along Lake Champlain, in Vermont and New York,
kindred in character to that above described in respect to the Erie
Canal. It brought into the market lands and produce which before had
been worthless, and was a great blessing to all concerned.

There can be no doubt that the building of the Erie Canal was the wisest
and most far-seeing enterprise of the age. It has left a permanent and
indelible mark upon the face of the republic of the United States in the
great communities it has directly assisted to build up at the West, and
in the populous metropolis it created at the mouth of the Hudson River.
None of the canals which have been built to compete with it have yet
succeeded in regaining for their States what was lost to them when the
Erie Canal went into operation. This water route is still the most
important artificial one of its class in the country, and is only
equaled by the Welland Canal in Canada, which is its closest rival. Now
that it is free, it will retain its position as the most popular water
route to the sea from the great West. The Mississippi River will divert
from it all the trade flowing to South America and Mexico; but for the
northwest it will be the chief water highway to the ocean.

       *       *       *       *       *




COTTRAU'S LOCOMOTIVE FOR ASCENDING STEEP GRADES.


We borrow, from our contemporary _La Nature_, the annexed figure,
illustrating an ingenious type of locomotive designed for equally
efficient use on both level surfaces and heavy grades.

[Illustration: COTTRAU'S LOCOMOTIVE FOR ASCENDING STEEP GRADES.]

As well known, all the engines employed on level roads are provided with
large driving wheels, which, although they have a comparatively feeble
tractive power, afford a high speed, while, on the contrary, those that
are used for ascending heavy grades have small wheels that move slowly,
but possess, as an offset, a tractive power that enables them to
overcome the resistances of gravity.

M. Cottrau's engine possesses the qualities of both these types, since
it is provided with wheels of large and small diameter, that may be used
at will. These two sets of wheels, as may be seen from the figure, are
arranged on the same driving axle. The large wheels are held apart
the width of the ordinary track, while the small wheels are placed
internally, or as in the case represented in the figure, externally.
These two sets of wheels, being fixed solidly to the same axle, revolve
together.

On level surfaces the engine rests on the large wheels, which revolve
in contact with the rails of the ordinary track, and it then runs with
great speed, while the auxiliary wheels revolve to no purpose. On
reaching an ascent, on the contrary, the engine meets with an elevated
track external or internal to the ordinary one, and which engages with
the auxiliary wheels. The large wheels are then lifted off the ordinary
track and revolve to no purpose. In both cases, the engine is placed
under conditions as advantageous as are those that are built especially
for the two types of roads. The idea appears to be a very ingenious one,
and can certainly be carried out without disturbing the working of the
locomotive. In fact, the same number of piston strokes per minute may
be preserved in the two modes of running, so as to reduce the speed in
ascending, in proportion to the diameters of the wheels. There will thus
occur the same consumption of steam. On another hand, there is nothing
to prevent the boiler from keeping up the same production of steam, for
it has been ascertained by experience, on the majority of railways, that
the speed of running has no influence on vaporization, and that the same
figures may be allowed for passenger as for freight locomotives.

The difficulties in the way of construction that will be met with in the
engine under consideration will be connected with the placing of the
double wheels, which will reduce the already limited space at one's
disposal, and with the necessity that there will be of strengthening all
the parts of the mechanism that are to be submitted to strain.

The installation of the auxiliary track will also prove a peculiarly
delicate matter; and, to prevent accidents, some means will have to be
devised that will permit the auxiliary wheels to engage with this
track very gradually. Still, these difficulties are perhaps not
insurmountable, and if M. Cottrau's ingenious arrangement meets with
final success in practice, it will find numerous applications.

       *       *       *       *       *




BACHMANN'S STEAM DRIER.


The apparatus shown in the annexed cuts is capable of effecting a
certain amount of saving in the fuel of a generator, and of securing a
normal operation in a steam engine. If occasion does not occur to blow
off the motive cylinder frequently, the water that is carried over
mechanically by the steam, or that is produced through condensation in
the pipes, accumulates therein and leaks through the joints of the cocks
and valves. This is one of the causes that diminish the performance of
the motor.

[Illustration: BACHMANN'S STEAM DRIER. FIG. 1.]

The steam drier under consideration has been devised by Mr. Bachmann
for the purpose of doing away with such inconveniences. When applied to
apparatus employed in heating, for cooking, for work in a vacuum, it may
be affixed to the pipe at the very place where the steam is utilized, so
as to draw off all the water from the mixture.

As shown by the arrows in Fig 1, the steam enters through the orifice,
D, along with the water that it carries, gives up the latter at P, and
is completely dried at the exit, R. The partition, g, is so arranged
as to diminish the section of the steam pipe, in order to increase the
effect of the gravity that brings about the separation of the mixture.
The water that falls into the space, P, is exhausted either by means of
a discharge cock (Fig. 1), which gives passage to the liquid only, or
by the aid of an automatic purge-cock (Figs. 2 and 3), the locating of
which varies with the system employed. This arrangement is preferable
to the other, since it permits of expelling the water deposited in the
receptacle, P, without necessitating any attention on the part of the
engine-man.

       *       *       *       *       *




H.S. PARMELEE'S PATENT AUTOMATIC SPRINKLER.


The inventor says: "The automatic sprinkler is a device for
automatically extinguishing fires through the release of water by means
of the heat of the fire, the water escaping in a shower, which is thrown
in all directions to a distance of from six to eight feet. The sprinkler
is a light brass rose, about 1½ inches diameter and less than two inches
high entire, the distributer being a revolving head fitted loosely to
the body of the fixed portion, which is made to screw into a half inch
tube connection. The revolution of the distributer is effected by the
resistance the water meets in escaping through slots cut at an angle
in the head. The distribution of water has been found to be the most
perfect from this arrangement. Now, this distributing head is covered
over with a brass cap, which is soldered to the base beneath with an
alloy which melts at from 155 to 160 degrees. No water can escape until
the cap is removed. The heat of an insignificant fire is sufficient to
effect this, and we have the practical prevention of any serious damage
or loss through the multiplication of the sprinkler.

[Illustration: PARMELEE'S PATENT AUTOMATIC SPRINKLER. FIG. 1.--Section
of Sprinkler with Cap on.]

The annexed engravings represent the sprinkler at exact size for
one-half inch connection. Fig. 1 shows a section with the cap covering
over the sprinkler, and soldered on to the base. Fig. 2 shows the
sprinkler with the cap off, which, of course, leaves the water free to
run from the holes in fine spray in all directions. Fig. 1 shows the
base hollowed out so as to allow the heat to circulate in between the
pipe and the base of the sprinkler, thus allowing the heat to operate on
the _inside_ as well as on the outside of the sprinkler; thus, in case
of fire, it is very quickly heated through sufficiently to melt the
fusible solder. These sprinklers are all tested at 500 lb., consequently
they can never leak, and cannot possibly be opened, except by heat,
by any one. As the entire sprinkler is covered by a heavy brass cap,
soldered on, it cannot by any means be injured, nor can the openings in
the revolving head ever become filled with dust.

[Illustration: PARMELEE'S PATENT AUTOMATIC SPRINKLER. FIG.2--Sprinkler
with cap off.]

It is so simple as to be easily understood by any one. As soon as the
sprinkler becomes heated to 155 degrees, the cap will become unsoldered,
and will then immediately be blown entirely off by the force of the
water in the pipes and sprinkler. These caps cannot remain on after
the fusible metal melts, if there is the least force of water. A man's
breath is sufficient to blow them off.

The arrangement commences with one or more main supply pipes, either fed
from a city water pipe or from a tank, as the situation will admit.
If desired, the tank need only be of sufficient size to feed a few
sprinklers for a short time, and then dependence must be placed upon
a pump for a further supply of water, if necessary. The tank, however
small, will insure the automatic and prompt working of the sprinklers
and alarm, and by the time the tank shall become empty the pumps can
be got at work. It is most desirable, however, in all cases to have an
abundant water supply without resorting to pumps, if it is possible.

In the main supply pipe or pipes is placed our patent alarm valve,
which, as soon as there is any motion of the water in the pipe, opens,
and moves a lever, which, by connecting with a steam whistle valve by
means of a wire, will blow the whistle and will continue to do so until
either the steam or the water is stopped. Tins constitutes the alarm,
and is positive in its motion. No water can possibly flow from the line
of pipes without opening this valve and blowing the whistle. We also put
in an automatic alarm bell when desired.

From the main pipe other pipes are run, generally lengthways of the
building, ten feet from each side and twenty feet apart. At every ten
feet on these pipes we place five feet of three-quarter inch pipe,
reaching each side, at the end of which is placed the sprinkler in an
elbow pointing toward the ceiling. This arrangement is as we place them
in all cotton and woolen mills, but may be varied to suit different
styles of buildings.

The sprinkler is made of brass, and has a revolving head, with four
slots, from which the water flies in a very fine and dense spray on
everything, and filling the air very completely for a radius of seven or
eight feet all around; thus rendering the existence of any fire in that
space perfectly impossible; and as the sprinklers are only placed ten
feet apart, and a fire cannot start at a greater distance than from five
to six feet from one or more of them, it is assured that all parts of a
building are fully protected.

Over each one of these sprinklers is placed a brass cap, which fits
closely over and passes below the base, where it is soldered on with a
fusible metal that melts as soon as it is heated to 155 degrees.

As soon as a fire starts in any part of a building, heat will be
generated and immediately rise toward the ceiling, and the sprinkler
nearest the fire will become heated in a very few moments to the
required 155 degrees, when the cap will become loosened and will be
forced off by the power of the water. The water will then be spread in
fine spray on the ceiling over the fire, also directly on the fire and
all around for a diameter of from fourteen to eighteen feet. This spray
has been fully tried, and it is found to be entirely sufficient to
extinguish any fire within its reach which can be made of any ordinary
materials.

As soon as the cap on any sprinkler becomes loosened by the heat of a
fire and is forced off, a current of water is produced in the main pipe
where the alarm valve is placed, and as the passage through it is dosed,
the water cannot pass without opening the valve and thus moving the
lever to which the steam whistle valve is attached; by this motion the
whistle valve is opened, and the whistle will blow until it is stopped
by some one."

       *       *       *       *       *




INSTRUMENT FOR DRAWING CONVERGING STRAIGHT LINES.

[Footnote: Paper by Prof. Fr. Smigaglia, read at the reunion of the
Engineers and Architects of Rome.]


1. LET A and B be two fixed points and A C and C B two straight lines
converging at C and moving in their plane so as to always remain based
on this point (Fig. 1). The geometrical place of the positions occupied
by C is the circumference of the circle which passes through the three
points A, B, and C. Now let C F be a straight line passing through C. On
prolonging it, it will meet the circumference A C B I at a point I. If
the system of three converging--lines takes a new position A C' F B,
it is evident F' B' prolonged will pass through I, because the angles
[alpha] and [beta] are invariable for any position whatever of the
system.

[Illustration: Fig. 1.]

2. In the particular case in which [alpha] = [beta] (Fig. 2), the point
I is found at the extremity of the diameter, and, consequently, for a
given distance A B, or for a given length C D, such point will be at its
maximum distance from C.

[Illustration: Fig. 2.]

3. This granted, it is easy to construct an instrument suitable for
drawing converging lines which shall prove useful to all those who have
to do with practical perspective. For this purpose it is only necessary
to take three rulers united at C (Fig. 3), to rest the two A C and C B
against two points or needles A and B, and to draw the lines with the
ruler C F, in placing the system (§ 1) in all positions possible. The
three rulers may be inclined in any way whatever toward each other, but
(§ 2) it is preferable to take the case where [alpha] = [beta].

[Illustration: Fig. 3.]

4. Let us suppose that the instrument passes from the position I to
position III (Fig. 4). Then the ruler C A will come to occupy the
position B A, from the fact that the instrument, continuing to move in
the same direction, will roll around the point B. It is well, then, to
manage so that the system shall have another point of support. For that
reason I prolong C B, take B C' = B C, draw C' I, and describe the
circumference--the geometrical place of the points C'. I take C' D = C'
B and obtain at D the position of the fixed point at which the needle
is inserted. In Fig. 4 are represented different positions of the
instrument; and it may be seen that all the points C C', and the centers
O O', are found upon the circumferences that have their center at I.

[Illustration: Fig. 4.]

5. The manipulation and use of the instrument are of the simplest
character. Being given any two straight converging lines whatever,
[alpha] [beta] and [gamma] [delta] (Fig. 5), in order to trace all the
others I insert a needle at A and arrange the instrument as seen at S. I
draw A B and A B', and from there carry it to S' in such a way that the
ruler being on [gamma] [delta], one of the resting rulers passes through
A. I draw the line C B which meets A B at the point B, the position
sought for the second needle. In order to draw the straight lines which
are under [alpha] [beta], it is only necessary to hold the needle A in
place and to fix one at B', making A B' = A B. In this case S" indicates
one of the positions of the instrument.

[Illustration: Fig. 5.]

6. The point A was chosen arbitrarily, but it is evident that that of
the needles depends on its distance from the point of convergence. Thus,
on taking A' instead of A in the case of Fig. 3, they approach, while
the contrary happens on choosing the point A". It is clear that the
different positions that a needle A may take are found on a straight
line which runs to the point of meeting.

7. If the instrument were jointed or hinged at C, that is to say, so
that we could at will modify the angle of the resting ruler, we might
make the position of the needles depend on such angle, and conversely.

8. Being given the length C I (Fig. 6), to establish the position of the
needles so that all the lines outside of the sheet shall converge at I.
To do this, it is well to determine C D, and then to draw the straight
line A D B perpendicular to C I, so as to have at A and B the points at
which the needles must be placed.

[Illustration: Fig. 6.]

Then

                       ___      ___
            ___        AD²      CD²
  CD x DI = AD². CD = ---- = --------- tang²[alpha],
                       DI     CI - CD

[TEX: CD \times DI = \overline{AD^2}.\ CD = \frac{\overline{AD^2}}{DI} =
\frac{\overline{CD^2}}{CI-CD} \tan^2 \alpha]

whence

               CI
  CD = ------------------ or CD = CI cos²[alpha].    (1)
        I + tang²[alpha]

[TEX: CD = \frac{CI}{I + \tan^2 \alpha}\ \text{or}\ CD = CI \cos^2
\alpha.]

9. If the instrument is jointed, the absolute values being

            _____________
           /
  AD = \  /  CD(CI - CD) ,   (2)
        \/

[TEX: AD = \sqrt{CD(CI - CD)}]

it suffices to take for CD a suitable value and to calculate AD.

If, for example, the value of C D is represented by C D', the instrument
takes the position A' C B', and the needles will be inserted at A' and
B' on the line A' D' B', which is perpendicular to C I.

10. If the position of the instrument, and consequently that of the
needles, has been established, and we wish to know the distance C I, we
will have

           CD
  CI = ------------ ;    (3)
       cos²[alpha]

[TEX: CI = \frac{CD}{\cos^2 \alpha}]

or, again,

         ___
         AC²
  CI =  -----            (4)
         CD'

[TEX: CI = \frac{\overline{AC^2}}{CD'}]

11. In order to avoid all calculation, we may proceed thus: If I wish to
arrange the instrument so that C I represents a given quantity (§ 8),
I take (Fig. 7) the length Ci = CI/n, where n is any entire number
whatever.

[Illustration: Fig. 7.]

In other terms, Ci is the reduction to the scale of CI.

I describe the circumference C b i a, and arrange the instrument as seen
in the figure, and measure the length C b.

It is visible that

  C i     1     C b     C d
 ----- = --- = ----- = ------; then C B = n.C b   (5)
  C I     n     C B     C D

  CD = n.C d;   (6)

and, consequently, the position of the needles which are found at A and
B are determined.

12. The question treated in § 10, then, is simply solved. In fact, on
describing the circumference C b i a with any radius whatever, I shall
have

       C B
  n = -----;      (7)
       c b

and, consequently,

  C I = n.C i     (8)

13. As may be seen, the instrument composed of three firmly united
rulers is the simplest of all and easy to use. Any one can construct it
for himself with a piece of cardboard, and give the angle 2 [alpha] the
value that he thinks most suitable for each application. The greater
2 [alpha] is, the shorter is the distance at which we should put the
needles for a given point of meeting.

14 The jointed instrument may be constructed as shown in Figs 8, 9, and
10. The three pieces, A. B, and C, united by a pivot, O, in which there
is a small hole, are of brass or other metal. Rulers may be easily
procured of any length whatever. The instrument is Y-shaped. In the
particular case in which [alpha] = 180° it becomes T-shaped, and serves
to draw parallel lines.

[Illustration: Fig. 8, Fig. 9, Fig. 10]

15. The instrument may be used likewise, as we have seen, to draw arcs
of circles of the diameter C I or of the radius A O = r, whose center o
falls outside the paper. The pencil will be rested on C. We may operate
as follows (Fig. 2): Being given the direction of the radii A O and B
O, or, what amounts to the same thing, the tangents to the curve at the
given points, A and B to be united, we draw the line A D and raise at
its center the perpendicular D C, which, prolonged, passes necessarily
through the center. It is necessary to calculate the length C D.

We shall have

                 ___ ___           ___
  CD (2r - CD) = AD².CD² - 2r.CD + AD² = o.

[TEX: CD (2r - CD) = \overline{AD^2}.\overline{CD^2} - 2r.CD +
\overline{AD^2} = o.]

                _________
               /     ___
  CD = r ± \  / r² - AD²  .
            \/

[TEX: CD = r ± \sqrt{r^2 - \overline{AD^2}}.]

It is evident that the lower sign alone suits our case, for d < r;
consequently,

                _________
               /     ___
  CD = r - \  / r² - AD²  .   (9)
            \/

[TEX: CD = r - \sqrt{r^2 - \overline{AD^2}}.]

Having obtained C, we put the instrument in the direction A B C. Then
each point of C F describes a circumference of the same center o.

16. If the distance of the points A and B were too great, then it
would be easy to determine a series of points belonging to the arc of
circumference sought (Fig. 4).

Being given C, the direction C I, and C I = R, on C I I lay off C E = d,
draw A E B perpendicularly, and calculate C A or A E. I shall have

                ___
  d = (R - d) = AE²;

[TEX: d = (R - d) = \overline{AE^2};]

or, as absolute value,

             __________
            /
  A E = \  / d (R - d) .    (10)
         \/

[TEX: AE = \sqrt{d (R-d)}]

The instrument being arranged according to A C B, I prolong C B and take
B C' = B C, when C' will be one of the points sought. It will be readily
understood how, by repeating the above operations, but by varying the
value of d, we obtain the other intermediate points, and how we may
continue the operation to the right of C' with the process pointed out.

17. If the three rulers were three arcs of a large circle of a sphere,
the instrument might serve for drawing the meridians on such sphere.

18. If we imagine, instead of three axes placed in one plane and
converging at one point, a system of four axes also converging in one
point, but situated in any manner whatever in space, and if we rest
three of them against three fixed points, we shall be able to solve in
space problems analogous to those that have just been solved in a plane.
If we had, for example, to draw a spherical vault whose center was
inaccessible, we might adopt the same method.--_Le Génie Civil_.

       *       *       *       *       *




FEED-WATER HEATER AND PURIFIER.

[Footnote: A paper read before the Franklin Institute.]

By GEORGE S. STRONG.


In order to properly understand the requirements of an effective
feed-water purifier, it will be necessary to understand something of the
character of the impurities of natural waters used for feeding
boilers, and of the manner in which they become troublesome in causing
incrustation or scale, as it is commonly called, in steam boilers. All
natural waters are known to contain more or less mineral matter, partly
held in solution and partly in mechanical suspension. These mineral
impurities are derived by contact of the water with the earth's surface,
and by percolation through its soil and rocks. The substances taken
up in solution by this process consist chiefly of the carbonates
and sulphates of lime and magnesia, and the chloride of sodium. The
materials carried in mechanical suspension are clay, sand, and vegetable
matter. There are many other saline ingredients in various natural
waters, but they exist in such minute quantities, and are generally so
very soluble, that their presence may safely be ignored in treating of
the utility of boiler waters.

Of the above named salts, the carbonates of lime and magnesia are
soluble only when the water contains free carbonic acid.

Our American rivers contain from 2 to 6 grains of saline matter to the
gallon in solution, and a varying quantity--generally exceeding 10
grains to the gallon--in mechanical suspension. The waters of wells and
springs hold a smaller quantity in suspension, but generally carry a
larger percentage of dissolved salts in solution, varying from 10 to 650
grains to the gallon.

When waters containing the carbonates of lime and magnesia in solution
are boiled, the carbonic acid is driven off, and the salts, deprived of
their solvent, are rapidly precipitated in fine crystalline particles,
which adhere tenaciously to whatever surface they fall upon. With
respect to the sulphate of lime, the case is different. It is at best
only sparingly soluble in water, one part (by weight) of the salt
requiring nearly 500 parts of water to dissolve it. As the water
evaporates in the boiler, however, a point is soon reached where
supersaturation occurs, as the water freshly fed into it constantly
brings fresh accessions of the salt; and when this point is reached,
the sulphate of lime is precipitated in the same form and with the same
tenaciously adherent quality as the carbonates. There is, however,
a peculiar property possessed by this salt which facilitates its
precipitation, namely, that its solubility in water diminishes as the
temperature rises. This fact is of special interest, since, if properly
taken advantage of, it is possible to effect its almost complete removal
from the feed-water of boilers,

There is little difference in the solubility of the sulphate of lime
until the temperature has risen somewhat above 212° Fahr., when it
rapidly diminishes, and finally, at nearly 300°, all of this salt,
held in solution at lower temperatures, will be precipitated when the
temperature has risen to that point. The following table[1] represents
the solubility of sulphate of lime in sea water at different
temperatures:

  Temperature.                 Percentage Sulph.
   Fahr.                      Lime held in Solution.
    217°                              0.500
    219°                              0.477
    221°                              0.432
    227°                              0.395
    232°                              0.355
    236°                              0.310
    240°                              0.267
    245°                              0.226
    250°                              0.183
    255°                              0.140
    261°                              0.097
    266°                              0.060
    271°                              0.023
    290°                              0.000

[Footnote 1: _Vide_ Burgh, "Modern Marine Engineering," page 176 _et
seq._ M. Cousté, _Annales des Mines_ V 69. _Recherches sur Vincrustation
des Chaudières a vapour_. Mr. Hugh Lee Pattison, of Newcastle-on-Tyne,
at the meeting of the Institute of Mechanical Engineers of Great
Britain, in August, 1880, remarked on this subject that "The solubility
of sulphate of lime in water diminishes as the temperature rises. At
ordinary temperatures pure water dissolves about 150 grains of sulphate
of lime per gallon; but at a temperature of 250° Fahr., at which the
pressure of steam is equal to about 2 atmospheres, only about 40 grains
per gallon are held in solution. At a pressure of 3 atmospheres, and
temperature of 302° Fahr., it is practically insoluble. The point
of maximum solubility is about 95° Fahr. The presence of magnesium
chloride, or of calcium chloride, in water, diminishes its power of
dissolving sulphate of lime, while the presence of sodium chloride
increases that power. As an instance of the latter fact, we find a
boiler works much cleaner which is fed alternately with fresh water and
with brackish water pumped from the Tyne when the tide is high than one
which is fed with fresh water constantly."]

These figures hold substantially for fresh as well as for sea water, for
the sulphate of lime becomes wholly insoluble in sea water, or in soft
water, at temperatures comprised between 280° and 300° Fahr.

It appears from this that it is simply necessary to heat water up to a
temperature of 250° in order to effect the precipitation of four fifths
of the sulphate of lime it may have contained, or to the temperature of
290° in order to precipitate it entirely. The bearing of these facts on
the purification of feed-waters will appear further on. The explanation
offered to account for the gradually increasing insolubility of sulphate
of lime on heating, is, that the hydrate, in which condition it exists
in solution, is partially decomposed, anhydrous calcic sulphate
being formed, the dehydration becoming more and more complete as the
temperature rises. Sulphate of magnesia, chloride of sodium (common
salt), and all the other more soluble salts contained in natural waters
are likewise precipitated by the process of supersaturation, but owing
to their extreme solubility their precipitation will never be effected
in boilers; all mechanically suspended matter tends naturally to
subside.

Where water containing such mineral and suspended matter is fed to a
steam boiler, there results a combined deposit, of which the carbonate
of lime usually forms the greater part, and which remains more or less
firmly adherent to the inner surfaces of the boiler, undisturbed by the
force of the boiling currents. Gradually accumulating, it becomes harder
and thicker, and, if permitted to accumulate, may at length attain such
thickness as to prevent the proper heating of the water by any fire that
may be maintained in the furnace. Dr. Joseph G. Rogers, who has made
boiler waters and incrustations a subject of careful study, declares
that the high heats necessary to heat water through thick scale will
sometimes actually convert the scale into a species of glass, by
combining the sand, mechanically separated, with the alkaline salts. The
same authority has carefully estimated the non-conducting properties
of such boiler incrustations. On this point he remarks that the evil
effects of the scale are due to the fact that it is relatively a
nonconductor of heat. As compared with iron, its conducting power is
as 1 to 37½, consequently more fuel is required to heat water in an
incrusted boiler than in the same boiler if clean. Rogers estimates that
a scale 1-16th of an inch thick will require the extra expenditure of
15 per cent. more fuel, and this ratio increases as the scale grows
thicker. Thus, when it is one-quarter of an inch thick, 60 per cent.
more fuel is needed; one-half inch, 112 per cent. more fuel, and so on.

Rogers very forcibly shows the evil consequences to the boiler from the
excessive heating required to raise steam in a badly incrusted boiler,
by the following illustration: To raise steam to a pressure of 90 pounds
the water must be heated to about 320° Fahr. In a clean boiler of
one-quarter inch iron this may be done by heating the external surface
of the shell to about 325° Fahr. If, now, one-half an inch of scale
intervenes between the boiler shell and the water, such is its quality
of resisting the passage of heat that it will be necessary to heat the
fire surface to about 700°, almost to a low red heat, to effect the same
result. Now, the higher the temperature at which iron is kept the more
rapidly it oxidizes, and at any heat above 600° it very soon becomes
granular and brittle, and is liable to bulge, crack, or otherwise give
way to the internal pressure. This condition predisposes the boiler to
explosion and makes expensive repairs necessary. The presence of such
scale, also, renders more difficult the raising, maintaining, and
lowering of steam.

The nature of incrustation and the evils resulting therefrom having been
stated, it now remains to consider the methods that have been devised
to overcome them. These methods naturally resolve themselves into
two kinds, chemical and mechanical. The chemical method has two
modifications; in one the design is to purify the water in large tanks
or reservoirs, by the addition of certain substances which shall
precipitate all the scale-forming ingredients before the water is fed
into the boiler; in the other the chemical agent is fed into the boiler
from time to time, and the object is to effect the precipitation of the
saline matter in such a manner that it will not form solid masses of
adherent scale. Where chemical methods of purification are resorted to,
the latter plan is generally followed as being the least troublesome. Of
the many substances used for this purpose, however, some are measurably
successful; the majority of them are unsatisfactory or objectionable.

The mechanical methods are also very various. Picking, scraping,
cleaning, etc., are very generally resorted to, but the scale is so
tenacious that this only partially succeeds, and, as it necessitates
stoppage of work, it is wasteful. In addition to this plan, a great
variety of mechanical contrivances for heating and purifying the
feed-water, by separating and intercepting the saline matter on its
passage through the apparatus, have been devised. Many of these are of
great utility and have come into very general use. In the Western States
especially, where the water in most localities is heavily charged
with lime, these mechanical purifiers have become quite indispensable
wherever steam users are alive to the necessity of generating steam with
economy.

Most of these appliances, however, only partly fulfill their intended
purposes. They consist essentially of a chamber through which the
feed-water is passed, and in which it is heated almost to the boiling
point by exhaust steam from the engine. According to the temperature
to which the water is heated in this chamber, and the length of time
required for its passage through the chamber, the carbonates are more or
less completely precipitated, as likewise the matter held in mechanical
suspension. The precipitated matter subsides on shelves or elsewhere in
the chamber, from which it is removed from time to time. The sulphate
of lime, however, and the other soluble salts, and in some cases also a
portion of the carbonates that were not precipitated during the brief
time of passage through the heater, are passed on into the boiler.

Appreciating this insufficiency of existing feed-water purifiers to
effectually remove these dangerous saline impurities, the writer in
designing the feed-water heater now to be described paid special
attention to the separation of all matters, soluble and insoluble; and
he has succeeded in passing the water to the boilers quite free from any
substance which would cause scaling or coherent deposit. His attention
was called more particularly to the necessity of extreme care in this
respect, through the great annoyance suffered by steam users in the
Central and Western States, where the water is heavily charged with
lime. Very simple and even primitive boilers are here used; the most
necessary consideration being handiness in cleaning, and not the highest
evaporative efficiency. These boilers are therefore very wasteful, only
evaporating, when covered with lime scale, from two to three pounds of
water with one pound of the best coal, and requiring cleansing once
a week at the very least. The writer's interest being aroused, he
determined, if possible, to remedy these inconveniences, and accordingly
he made a careful study of the subject, and examined all the heaters
then in the market. He found them all, without exception, insufficient
to free the feed-water from the most dangerous of impurities, namely,
the sulphate and the carbonate of lime.

Taking the foregoing facts, well known to chemists and engineers, as the
basis of his operations, the writer perceived that all substances likely
to give trouble by deposition would be precipitated at a temperature of
about 250° F.

His plan was, therefore, to make a feed-water heater in which the water
could be raised to that temperature before entering the boiler. Now, by
using the heat from the exhaust steam the water may be raised to between
208° and 212° F. It has yet to be raised to 250° F.; and for this
purpose the writer saw at once the advantage that would be attained by
using a coil of live steam from the boiler. This device does not cause
any loss of steam, except the small loss due to radiation, since the
water in any case would have to be heated up to the temperature of the
steam on entering the boiler. By adopting this method, the chemical
precipitation, which would otherwise occur in the boiler, takes place
in the heater; and it is only necessary now to provide a filter, which
shall prevent anything passing that can possibly cause scale.

Having explained as briefly as possible the principles on which the
system is founded, the writer will now describe the details of the
heater itself.

In Figs. 1 and 2 are shown an elevation and a vertical section of
the heater. The cast-iron base, A, is divided into two parts by the
diaphragm, B. The exhaust steam enters at C, passes up the larger tubes,
D, which are fastened into the upper shell of the casting, returns by
the smaller tubes, E, which are inside the others, and passes away by
the passage, F. The inner tube only serves for discharge. It will be
seen at once that this arrangement, while securing great heating surface
in a small space, at the same time leaves freedom for expansion and
contraction, without producing strains. The free area for passage of
steam is arranged to be one and a half times that of the exhaust pipe,
so that there is no possible danger of back pressure. The wrought iron
shell, G, connecting the stand, A, with the dome, H, is made strong
enough to withstand the full boiler pressure. An ordinary casing, J,
of wood or other material prevents loss by radiation of heat. The
cold water from the pump passes into the heater through the injector
arrangement, K, and coming in contact with the tubes, D, is heated; it
then rises to the coil, L, which is supplied with steam from the boiler,
and thus becomes further heated, attaining there a temperature of from
250° to 270° F., according to the pressure in the boiler. This high
temperature causes the separation of the dissolved salts; and on the way
to the boiler the water passes through the filter, M, becoming thereby
freed from all precipitated matter before passing away to the boiler at
N. The purpose of the injector, K, and the pipe passing from O to K, is
to cause a continual passage of air or steam from the upper part of the
dome to the lower part of the heater, so that any precipitate carried up
in froth may be again returned to the under side of the filter, in order
more effectually to separate it, before any chance occurs of its passing
into the boiler.

[Illustration: FIG. 1.--Elevation. FIG. 2.--Vertical Section]

The filter consists of wood charcoal in the lower half and bone black
above firmly held between two perforated plates, as shown. After the
heater has been in use for from three to ten hours, according to the
nature of the water used, it is necessary to blow out the heater, in
order to clear the filter from deposit. To do this, the cock at R is
opened, and the water is discharged by the pressure from the boiler. The
steam is allowed to pass through the heater for some little time, in
order to clear the filter completely. After this operation, all is ready
to commence work again. By this means the filter remains fit for use for
months without change of the charcoal.

Where a jet condenser is used, either of two plans may be adopted. One
plan takes the feed-water from the hot well and passes the exhaust from
the feed pumps through the heater, using at the same time an increased
amount of coil for the live steam. By this means a temperature of water
is attained high enough to cause deposition, and at the same time to
produce decomposition of the oil brought over from the cylinders. The
other plan places the heater in the line of exhaust from the engine to
the condenser, also using a larger amount of coil. Both these methods
work well. The writer sometimes uses the steam from the coil to work the
feed pump; or, if the heater stands high enough, it is only necessary
to make a connection with the boiler, when the water formed by the
condensation of the steam runs back to the boiler, and thus the coil is
kept constantly at the necessary temperature.

In adapting the heater to locomotives, we were met with the difficulty
of want of space to put a heater sufficiently large to handle the
extremely large amount of water evaporated on a locomotive worked up to
its full capacity, being from 1,500 to 2,500 gallons per hour, or from
five hundred to one thousand h.p. We designed various forms of heaters
and tried them, but have finally decided on the one shown in the
engraving, Fig. 3, which consists of a lap welded tube, 13 inches
internal diameter, 12 feet long, with a cast-iron head which is divided
into two compartments or chambers by a diaphragm. Into this head are
screwed 60 tubes, one inch outside diameter and 12 feet long, which
are of seamless brass. These are the heating tubes, within which
are internal tubes for circulation only, which are screwed into the
diaphragm and extend to within a very short distance of the end of the
heating tube. The exhaust steam for heating is taken equally from both
sides of the locomotive by tapping a two-inch nipple with a cup shaped
extension on it in such a way as to catch a portion of the exhaust
without interfering with the free escape of the steam for the blast, and
without any back pressure, as it relieves the back pressure as much as
it condenses. The pipe from one side of the engine is connected with
the chamber into which the heating tubes are screwed, and is in direct
communication with them. The pipe from the other side is connected with
the chamber into which the circulating tubes are screwed. The beat of
the exhaust, working, as it does, on the quarters, causes a constant
sawing or backward and forward circulation of steam without any
discharge, and only the condensation is carried off.

The water is brought from the pump and discharged into the lower side of
the heater well forward, and passes around the heating tubes to the end,
when it is discharged into a pipe that carries it forward, either direct
to the check or into the purifier, which is located between the frames
under the boiler, and consists of a chamber in which are arranged a live
steam coil and a filter above the coil. The water coming in contact
with the coil, its temperature is increased from the temperature of the
exhaust, 210°, to about 250° Fahr., which causes the separation of the
lime salts as before described, and it then passes through the filter
and direct to the boiler from above the filter, which is cleansed by
blowing back through it as before described.

One of these heaters lately tested showed a saving in coal of 22 per
cent, and an increase of evaporation of 1.09 pounds of water per pound
of coal.--_Franklin Journal_.

       *       *       *       *       *




MONTEVERDE'S STATUE OF ARCHITECTURE.


This precious statue forms the noble figure that adorns the monument
erected to the memory of the architect Carles Sada, who died in 1873.
This remarkable funereal monument is 20 feet high, the superior portion
consisting of a sarcophagus resting upon a level base. Upon this
sarcophagus is placed the statue of "La Architectura," which we
reproduce, and which well exemplifies the genius of the author and
sculptor, Juli Monteverde.--_La Ilustració Catalana_.

[Illustration: LA ARCHITECTURA.--STATUE BY JULI MONTEVERDE.

ERECTED IN MEMORY OF THE ARCHITECT, CARLES SADA.]

       *       *       *       *       *




DESIGN FOR A GARDENER'S COTTAGE.


The illustration shows a gardener's cottage recently erected at Downes,
Devonshire, the seat of Colonel Buller, V.C., C.B, C.M.G., from the
designs of Mr. Harbottle, A.R.I.B.A., of Exeter. It is built of red
brick and tile, the color of which and the outline of the cottage give
it a picturesque appearance, seen through the beautiful old trees in one
of the finest parks in Devonshire.--_The Architect_.

[Illustration: Gardener's Cottage at DOWNES for Colonel Buller V.C.,
C.B., C.M.G., _E.H. Harbottle Architect_]

       *       *       *       *       *




PAPER MAKING "DOWN EAST."


Writing from Gilbertville, a Lewiston journal correspondent says:
Gilbertville, a manufacturing community in the town of Canton,
twenty-five miles from Lewiston, up the Androscoggin, is now a village
of over 500 inhabitants, where three years ago there was but a single
farmhouse. If a town had sprung into existence in a far Western
State with so much celerity, the phenomenon would not be considered
remarkable, perhaps; but growths of this kind are not indigenous to the
New England of the present era. Gilbertville has probably outstripped
all New England villages in the race of the past three years. It is only
one of the signs that old Maine is not dead yet.

Gilbert Brothers erected a saw mill here three years ago. A year later,
the Denison Paper Manufacturing Company, of Mechanic Falls, erected a
big pulp mill, which, also, the town voted to exempt from taxation for
ten years. The mills are valuable companions for each other. The pulp
mill utilizes all the waste of the saw mill. A settlement was speedily
built by the operatives. Gilbertville now boasts of a post-office, a
store, several large boarding houses, a nice school house, and over 500
inhabitants. The pulp mill employs seventy men. It runs night and day.
It manufactures monthly 350 cords of poplar and spruce into pulp. It
consumes monthly 500 cords of wood for fuel, 45 casks of soda ash,
valued at $45 per cask, nine car loads of lime, 24,000 pounds to the
car. It produces 1,000,000 pounds of wet fiber, valued at about $17,000,
monthly. The pay roll amounts to $3,500 per month.

The larger part of the stock used by the mill consists of poplar logs
floated down the Androscoggin and its tributaries. One thousand two
hundred cords of poplar cut in four-foot lengths are piled about the
mill; and a little further up the river are 5,000 cords more. The logs
are hauled from the river and sawed into lengths by a donkey engine,
which cuts about sixty cords per day, and pulls out fourteen logs at
a time. All the spruce slabs made by the saw mill are used with this
poplar. The wood is fed to a wheel armed with many sharp knives. It
devours a cord of wood every fifteen minutes. The four-foot sticks are
chewed into fine chips as rapidly as they can be thrust into the maw of
the chopper. They are carried directly from this machine to the top of
the mill by an endless belt with pockets attached. There are hatchways
in the attic floor, which open upon rotary iron boilers. Into these
boilers the chips are raked, and a solution of lime and soda ash is
poured over them.

This bath destroys all the resinous matter in the wood, and after
cooking five hours the chips are reduced to a mass of soft black pulp.
Each rotary will contain two cords of chips. After the cooking, the pulp
is dumped into iron tanks in the basement, where it is thoroughly washed
with streams of clean cold water. It is then pumped into a machine which
rolls it into broad sheets. These sheets are folded, and condensed by
a hydraulic press of 200 tons pressure. This process reduces its bulk
fifty per cent., and sends profuse jets of water flying out of it. The
soda ash, in which, mixed with lime and water, the chips are cooked, is
reclaimed, and used over and over again. The liquor, after it has been
used, is pumped into tanks on top of large brick furnaces. As it is
heated, it thickens. It is brought nearer and nearer the fire until it
crystallizes, and finally burns into an ash. Eighty per cent. of the ash
used is thus reclaimed. This process is an immense saving to the pulp
manufacturers. The work in the pulp mill is severe, and is slightly
tinged with danger.

Three thousand four hundred pounds of white ash to 2,100 pounds of lime
are the proportions in which the liquor in each vat is mixed. One does
not envy the lot of the stout fellows who crawl into the great rotaries
to stow away the chips. The hurry of business is so great that they
cannot wait for these boilers to cool naturally, after they have cooked
one batch, before putting in another. So they have a fan pump, to which
is attached a canvas hose, and with this blow cooling air currents into
the boiler, or "rotary," as they call it. The rotary is subjected to an
immense pressure, and is very stoutly made of thick iron plates, bolted
together.

Describing the business as carried on at Mechanic Falls, the same paper
says: There are six of these mills on the three dams over which the
Little Androscoggin falls. These are the Eagle, the Star, the Diamond,
the Union, the pulp, and the super calendering mills. The Eagle and the
Star mills run on book papers of various grades. The Union mill runs on
newspaper. The old Diamond mill now prepares pulp stock. The pulp mill
does nothing but bleach the rag pulp and prepare for the machines in the
other mills; while the super-calendering mill gives the paper an extra
finish when ordered. There is practically but one series of processes by
which the paper is made in the various mills.

It is a curious fact that America is not ragged enough to produce the
requisite amount of stock for its own paper mills. Nearly all the rags
used by the Denison Mills (and by others in various parts of the country
as well) are imported from the old countries. All the rags first go
through the "duster." This is a big cylindrical shell of coarse wire
netting. It is rapidly revolved, while a screw running through its
center is turned in the opposite direction. Air currents are forced
through it by a power fan. The rags are continuously fed into one end of
this shell, which is about ten feet long and four feet in diameter. The
screw forces them through the whole length of the shell, while they are
kept buzzing around and subjected to breezes which blow thick clouds of
dirt and dust out of them. The air of the room is thick with European
and Asiatic earth. It is swept up in great rolls on the floor. The man
who operates the duster should have leather lungs.

Overhead is a long room where thirty girls are busily sorting the rags
for the various grades of papers. That the dusting machine is no more
perfect than a human machine is evinced by the murky atmosphere of this
room, by the particles that lodge in the throat of the visitor, and
by the frequent coughing of the sorters. They protect their hair with
turbans of veiling, occasionally decorated with a bit of bright color.
These turbans give the room the appearance of an industrious Turkish
harem. Short, sharp scythe blades, like Turkish scimeters, gleam above
all the girls' benches. When a sorter wishes to cut a rag, she pulls it
across the edge of this blade, and is not obliged to hunt for a pair of
shears.

Curious discoveries are frequently made in the rags. Old pockets,
containing small sums of money, are occasionally found. A foreign coin
valued at about $3 was found a few days ago. In the paper stock, quaint
and valuable old books or pictures are found often. One of the workmen
has a museum composed of curiosities found amid the rags and shreds of
paper. Rev. Dr. Bolles, of Massachusetts, makes an annual pilgrimage
to Mechanic Falls for the sake of the rare old pamphlets, books, and
engravings that he may dig out.

Stuffed in hogsheads, the rags are lowered from this room through
a hatchway, and are given a red hot lime bath. They are placed in
ponderous cylinders of boiler iron, which revolve horizontally in great
gears high above the floor. A mixture of lime and water, which has been
prepared in large brick vats, is poured over them. An iron door, secured
by huge bolts, is closed on them. The cylinder slowly turns around, and
churns the rags in the lime-juice twelve hours. This process is called
bleaching. When the rags come out they are far from white, however. They
are of a uniform dirty brown hue. But the colors have lost their gripe.
When the rags shall have been submitted to the grinding and washing in
pure water, as we shall see them presently, they are easily whitened.
The lime bath is the purgatory of the paper stock.

Before we go any further, we must see what becomes of those soft
and lop-sided bundles which are going into the mills. These contain
chemically prepared wood fiber, a certain percentage of which is used
in nearly all the papers made now. It gives the paper a greater body,
although its fiber is not so strong as that made of rags. The pulp comes
down from Canton in soft brown sheets. These are at once bleached. The
brown fiber is placed in a bath of cold water and chlorate of lime.
There it quietly rests till a sediment settles at the bottom of the
tank. At an opportune moment the workman pours in a copious libation
of boiling water. This causes the escape of the chlorine gas, which
destroys all the color in the pulp. In half an hour it comes out, a mass
of smoking fibers as white as a snow heap. The drainers into which it
goes are large pens with perforated tile floors. The pulp remains in the
drainers till it so dry it is handled with a pitchfork.

We are now ready to look at the beating machines, which have to perform
a very important part in paper making. These are large iron tanks with
powerful grinders revolving in them. Barrow loads of the brown rags are
dumped into them, and clear cold water is poured in. The grinders are
then started. They chew the rags into fine bits. They keep the mass
of rags and water circulating incessantly in the tanks. Clean water
constantly flows in and dirty water as constantly flows out. In the
course of six hours the rags are reduced to a perfectly white pulpy
mass. There is one mill, as we have said, devoted exclusively to the
reduction of rags to this white pulp. It is dried in drainers such as we
saw a few moments ago filled with the wood fiber.

There are other beating machines just like these, which perform a
slightly different service. Their function may be compared to that of an
apothecary's mortar or a cook's mixing dish. The white rag stock and the
white wood fiber are mixed in these, in the required proportions.
At this stage, the pulp is adulterated with China clay, to give it
substance and weight; here the sizing (composed of resin and sal soda)
is put in; oil of vitriol, bluing, yellow ocher, and other chemicals are
added, to whiten or to tint the paper. These beaters are much like
so many soup kettles. Upon the kind, number, and proportion of the
ingredients depends the nature of the product. The percentages of rag
pulp, wood pulp, clay, coloring, etc., used, depend upon the quality of
paper ordered.

After the final beating, the mixture descends into a large reservoir
called the "stuff chest," whence it is pumped to the paper machine. The
pulp is of the consistency of milk when it pours from the spout of
the pumps on the paper machine. The latter is a complicated series of
rollers, belts, sieves, blankets, pumps, and gears, one hundred feet
long. To describe it or to understand a description of it would require
the vocabulary and the knowledge of a scientist. The milky pulp first
passes over a belt of fine wire cloth, through which the water partly
drains. It is ingeniously made to glide over two perforated iron plates,
under which pumps are constantly sucking. You can plainly see the broad
sheet of pulp lose its water and gain thickness as it goes over these
plates. Broad, blanket-like belts of felt take it and carry it over and
between large rolling cylinders filled with hot steam. These dry and
harden it into a sheet which will support itself; and without the aid of
blankets it winds among iron rolls, called calenders, which squeeze it
and give it surface. It is wound upon revolving reels at the end of the
machine.

If a better surface or gloss is required, it is carried to the super
calendering mill, where it is steamed and subjected to a long and
circuitous journey up and down tall stands of calenders upon calenders.
The paper is cut by machines having long, winding knives which revolve
slowly and cut, on the scissors principle--no two points of the blade
bearing on the paper with equal pressure at once. Girls pack the sheets
on the tables as they fall from the cutters, and throw out the damaged
or dirtied sheets. A small black spot or hole or imperfection of any
sort is sufficient to reject a sheet. In some orders fifty per cent. of
the sheets are thrown out. There is no waste, as the damaged paper is
ground into pulp again. Having been cut, the paper must be counted and
folded. Then it is packed into bundles for shipment. The young lady who
does the counting and folding is the wonder of the mill. Giving the
sheets a twist with one hand so as to spread open the edges, she gallops
the fingers of the other hand among them; and as quickly as you or I
could count three, she counts twenty-four and folds the quire. She takes
four sheets with a finger and goes her whole hand and one finger more;
thus she gets twenty-four sheets. Long practice is required to do the
counting rapidly and accurately. Twenty-four sheets, no more and no
less, are always found in her quires.

Papers of different grades are made of different stock, but by the same
process. Some paper stock is used. This must be bleached in lime and
soda ash. There are powerful steam engines in the mills for use when
the water is low. There are large furnaces and boilers which supply the
steam used in the processes.

The Messrs. Denison employ 175 hands at Mechanic Falls. Their pay roll
amounts to about $5,000 per month. The mills produce 350,000 pounds of
paper per month and they ship several car-loads of prepared wood-pulp,
in excess of that required for their own use, weekly. The annual value
of their product is not far from $300,000. They use, for sundries,
each month, 300 tons of coal, 100 casks of common lime, 250 gallons of
burning-oil, 28,000 pounds of chlorate of lime, 3,700 pounds of soda
ash. 10,000 pounds of resin. 24,000 pounds of sal soda, 22,000 pounds of
oil of vitriol, 22,000 pounds of China clay, etc.

       *       *       *       *       *




WHEAT-MEAL BREAD AS A MEANS OF DIMINISHING TUBERCULAR DISEASE.


By M. YATES, Hon. Sec. Bread Reform League, London.

It is well recognized that defective mineral nutrition is an important
factor in the production of rickets and bad teeth, but as its
influence in predisposing toward tuberculous disease is not so clearly
ascertained, will you kindly allow public attention to be directed to
a statement which was discussed at the Social Science and Sanitary
Congresses and which, if confirmed by further scientific research,
indicates a simple means of diminishing consumption, which, as Dr.
William Fair, F.R.S., says, "is the greatest, the most constant, and the
most dreadful of all the diseases that affect mankind." In "Phosphates
in Nutrition," by Mr. M.F. Anderson, it is stated that although the
external appearances and general condition of a body when death has
occurred from starvation are very similar to those presented in
tuberculous disease, in starvation, "from wasting of the tissues, caused
by the combustion of their organic matter, there would be an apparent
_increase_ in the percentage proportion of mineral matter; on the other
hand, in tubercular disease, there would be a material _decrease_ in the
mineral matter as compared with the general wasting." Analyses, made
by Mr. Anderson, of the vascular tissues of patients who have died
of consumption, scrofula, and allied diseases, show "a very marked
deficiency in the quantity of inorganic matter entering into their
composition; this deficiency is not confined to the organs or tissues
which are apparently the seat of the disease, but in a greater or lesser
degree pervades the whole capillary system."

The observations of Dr. Marcet, F.R.S., show that in phthisis there is
a considerable reduction of the normal amount of phosphoric acid in the
pulmonary tissues; and it is very probable that there is a general drain
of phosphoric acid from the system.

This loss may be caused by the expectoration and night-sweats, or it may
also be produced by defective mineral nutrition, either from deficient
supply in the food, or from non assimilation. But, whatever causes this
deficiency, it is universally acknowledged that it is essential the food
should contain a proper supply of the mineral elements. If the body is
well nourished, the resisting force of the system is raised. Professor
Koch and others, who accept the germ theory of disease to its fullest
extent, state that the minute organisms of tubercular disease do not
occur in the tissues of healthy bodies, and that when introduced into a
living body their propagation and increase are greatly favored by a low
state of the general health.

Dr. Pavy, F.R.S., showed in his address on the "Dietetics of Bread" that
in white flour, instead of obtaining the 23 parts of mineral matter
to 100 parts of nitrogenous matter--which is the accepted ratio of
a standard diet--we should only get 4.20 parts of mineral matter.
Professor Church states that 1 lb. of white flour has only 49 grains of
mineral matter, while 1 lb. of whole wheat meal has 119 grains. Whole
wheat meal, besides containing other essential mineral elements,
has double the amount of lime, and nearly three times the amount of
phosphoric acid; so that if defective mineral nutrition in any way
predisposes to consumption, the adoption of wheat meal prepared in a
digestible and palatable form is of primary importance for those who are
unable to obtain the phosphates from high-priced animal foods.

Wheat meal has also great advantages for those who are able to afford
animal food, for, as Dr. Pavy stated, "It acts as a greater stimulant to
the digestive organs."

It is probably due to this stimulating property of wheat meal that
people who have adopted it find they can digest animal fat much better
than previously. If this is corroborated by general experience, it may
be of great benefit in aiding the system to resist tendencies toward
consumption and scrofula, for these diseases are generally accompanied
by loss of the power of assimilating fat. It is believed that a
deficiency of oleaginous matter is a predisposing cause of tuberculous
disease. An important prophylactic, therefore, against such maladies,
would be a general increase in the use of butter and other fatty foods.

There is such good reason to believe that a low state of nutrition
favors the development of tuberculous disease, that parents cannot be
too strongly urged to provide their children with a proper supply of
healthy, nourishing, and pure food (under which term must, of course, be
included pure air and pure water), for by so doing they may often arrest
consumptive tendencies, and thus would be diminished the ravages of
that fatal disease which, when once established, is "the despair of the
physician, and the terror of the public."

       *       *       *       *       *




THE NEW YORK FISH COMMISSION PONDS AT CALEDONIA.


The capacity of the New York State fish farm at Caledonia is 6,000,000
fry a year. The recently issued report of the fish commissioners says
that this year the ponds will be worked to their full capacity.

The supply of spawn has been greater than could be hatched there, and
supplies were sent to responsible persons in every State in the Union to
be experimented with. At the date of issuing the report the supply of
stock fish at the hatchery embraced, it was estimated, a thousand salmon
trout, of weights ranging from four to twelve pounds; ten thousand
brook trout, from half a pound to two pounds in weight; thirty thousand
California mountain trout, weighing from a quarter of a pound to three
pounds; forty-seven hundred rainbow trout, of from a quarter of a
pound to two pounds' weight; and a large number of hybrids produced by
crossing and interbreeding of different members of the salmon tribe. In
this connection reference is made to the interesting fact that hybrids
of the fish family are not barren. Spawners produced by crossing the
male brook trout with the female salmon trout cast 72,000 eggs last
fall, which hatched as readily as the spawn of their progenitors. The
value of the stock of breeding fish at the hatchery is estimated at
$20,000.

The hatch of salmon trout this season was not far from 1,200,000, and
these will be distributed chiefly in the large lakes of the interior.
About a million little brook trout were produced. The commission doubts
whether much benefit has resulted from attempting to stock small streams
that have once been good trout waters, but the temperature of which has
been changed by cutting away the forest trees that overhung them. The
best results have been attained where the waters are of considerable
extent, especially those in and bordering on the wilderness in the
northern part of the State. The experiments with California trout, have
been very successful, and it is found that the streams most suitable for
them, are the Hudson, Genesee, Mohawk, Moose, Black, and Beaver rivers,
and the East and West Canada creeks. The commission hopes to hatch
6,000,000 or 8,000,000 shad this season at a cost of about $1,000.
Concerning German carp, the commissioners find that the water at
Caledonia is too cold for this fish, but think that carp would do well
in waters further south.

The commission awaits a more liberal appropriation of money before
beginning the work of hatching at the new State fish farm at Cold
Spring, on the north side of Long Island, thirty miles out from
Brooklyn.

       *       *       *       *       *




MIOCENE MAN.


Grant Allen, an English evolutionist, gives this imaginary picture
of our supposed ancestor: "We may not unjustifiably picture him to
ourselves as a tall and hairy creature, more or less erect, but with a
slouching gait, black faced and whiskered, with prominent, prognathous
muzza, and large, pointed canine teeth, those of each jaw fitted into
an interspace in the opposite row. These teeth, as Mr. Darwin suggests,
were used in the combats of the males. His forehead was no doubt low and
retreating, with bony bosses underlying the shaggy eyebrows, which
gave him a fierce expression, something like that of the gorilla. But
already, in all likelihood, he had learned to walk habitually erect, and
had begun to develop a human pelvis, as well as to carry his head more
straight on his shoulders. That some such animal must have existed seems
to me an inevitable corollary from the general principles of evolution
and a natural inference from the analogy of other living genera."

       *       *       *       *       *




GOULIER'S TUBE-GAUGE.


As well known, the method by which glass barometer tubes are made gives
them variable calibers. Not only do the different tubes vary in size,
but even the same tube is apt to have different diameters throughout
its length, and its sections are not always circular. Manufacturers
of barometers often have need to know exactly the dimensions of the
sections of these tubes, and to ascertain whether they are equal
throughout a certain length of tube, and this is especially necessary in
those instruments in which the surfaces of the sections of the reservoir
and tube must bear a definite ratio to one another. Having ascertained
that no apparatus existed for measuring the caliber of these and
anolagous tubes, and that manufacturers had been accustomed to make the
measurements by roundabout methods, Colonel Goulier has been led to
devise a small apparatus for the purpose, and which is shown in the
accompanying cuts.

[Illustration: GOULIER'S TUBE GAUGE. (Plan and longitudinal and
tranverse sections.)]

The extremity of a brass tube, T, 0.5 to 0.6 of a meter in length and
smaller in diameter than the tube to be gauged, is cut into four narrow
strips a few centimeters in length. The extremity of each of these
strips is bent toward the axis of the tube. Two of them, m and m',
opposite each other are made very flexible, and carry, riveted to their
extremities, two steel buttons, the heads of which, placed in the
interior, have the form of an obtuse quoin with rounded edge directed
perpendicular to the tube's axis. The other extremities of these buttons
are spherical and polished and serve as caliper points in the operation
of measuring. These buttons are given a thickness such that when the
edges of their heads are in contact, the external diameter of the tube
exceeds the distance apart of the two calibrating points by more than
one millimeter. But such distance apart is increased within certain
limits by inserting between the buttons a German silver wedge, L,
carried by a rod, t, which traverses the entire tube, and which is
maneuvered by a head, B, fixed to its extremity. This rod carries a
small screw, v, whose head slides in a groove, r, in the tube, so as
to limit the travel of the wedge and prevent its rotation. Beneath the
head, B, the rod is filed so as to give it a plane surface for the
reception of a divided scale. A corresponding slit in the top of the
tube carries the index, I, of the scale. The principal divisions of the
scale have been obtained experimentally, and traced opposite the index
when the calibrating points were exactly 7, 8, 9 etc., millimeters
apart. As the angle of the wedge is about one tenth, the intervals
between these divisions are about one centimeter. These intervals are
divided into ten parts, each of which corresponds to a variation in
distance of one tenth of a millimeter.

To calibrate a glass tube with this instrument, the tube is laid upon
the table, the gauge is inserted, and the buttons are introduced into
the section desired. The flat side of the head, B, being laid on the
table, arranges, as shown in the figure, the buttons perpendicular to
it. Then the measuring wedge is introduced until a stoppage occurs
through the contact of the buttons with the sides of the tube. Finally,
their distance apart is read on the scale. Such distance apart will be
the measure of a diameter or a chord of the tube's section, according as
the buttons have been kept in the diametral plane or moved out of it. In
order that the operator shall not be obliged to watch the position of
the line of calibrating buttons in obtaining the diameter, the following
arrangement has been devised: The sides of the measuring wedge are filed
off to a certain angle, and the ends of the corresponding strips, d and
d', are bent inward in the form of hooks, whose extremities always rest
on the faces of the directing wedges. The length of these hooks and the
angle of the wedge are such that the distance apart of the rounded backs
of the directing strips is everywhere less, by about one-thirtieth, than
that of the calibrating buttons. From this it will be seen that if the
wedge be drawn back, and inserted again after the tube has been turned,
we shall measure the diameter that is actually vertical. It becomes
possible, then, to determine the greatest and smallest diameters in a
few minutes; and, supposing the section elliptical, its area will be
obtained by multiplying the product of these two diameters by pi/4.

From the description here given it will be seen that Colonel Goulier's
apparatus is not only convenient to use, but also permits of obtaining
as accurate results as are necessary. Two sizes of the instrument are
made, one for diameters of from 7 to 10.5 mm., and the other for those
of from 10 to 15.5 mm. It is the former of these that is shown, of
actual size, in the cuts.

       *       *       *       *       *




SOLDERING WITHOUT AN IRON.


The following method for soldering without the use of a soldering iron
is given in the _Techniker_:

The parts to be joined are made to fit accurately, either by filing
or on a lathe. The surfaces are moistened with the soldering fluid, a
smooth piece of tin foil laid on, and the pieces pressed together and
tightly wired. The article is then heated over the fire or by means of
a lamp until the tin foil melts. In this way two pieces of brass can be
soldered together so nicely that the joint can scarcely be found.

With good soft solder, nearly all kinds of soldering can be done over
a lamp without the use of a "copper." If several piaces have to
be soldered on the same piece, it is well to use solder of unlike
fusibility. If the first piece is soldered with fine solder composed of
2 parts of lead, 1 of tin, and 2 of bismuth, there is no danger of its
melting when another place near it is soldered with bismuth solder, made
of 4 parts of lead, 4 of tin, and 1 of bismuth, for their melting points
differ so much that the former will not melt when the latter does. Many
solders do not form any malleable compounds.

In soldering together brass, copper, or iron, hard solder must be
employed; for example, a solder made of equal parts of brass and silver
(!). For iron, copper, or brass of high melting point, a good solder is
obtained by rolling a silver coin out thin, for it furnishes a tenacious
compound, and one that is not too expensive, since silver stretches out
well. Borax is the best flux for hard soldering. It dissolves the oxides
which form on the surface of the metal, and protects it from further
oxidation, so that the solder comes into actual contact with the
surfaces of the metal. For soft soldering, the well-known fluid, made by
saturating equal parts of water and hydrochloric acid with zinc, is to
be used. In using common solder rosin is the cheapest and best flux. It
also has this advantage, that it does not rust the article that it is
used on.--_Deutsche Industrie Zeitung_.

       *       *       *       *       *




WORKING COPPER ORES AT SPENCEVILLE.


From a letter in the Grass Valley _Tidings_ we make the following
extracts:

The Spenceville Copper Mining Company have 43 acres of copper-bearing
ground and 100 acres of adjoining land, which was bought for the timber.
There are a hoisting works, mill, roasting sheds, and leaching vats on
the ground, and they cover several acres.

On going around with Mr. Ellis, the first place we came to was the mine
proper, which is simply an immense opening in the ground covering about
one half of an acre, and about 80 feet deep. It has an incline running
down into it, by which the ore is hoisted to the surface. Standing on
the brink of this opening and looking down, we could see the men at
work, some drilling, others filling and running the cars to the incline
to be hoisted to the surface.

The ore is found in a sort of chloritic slate and iron pyrites which
follow the ledge all around. The ore itself is a fine-grained pyrite,
with a grayish color, and it is well suited by its sulphur and low
copper contents, as well as by its properties for heap roasting. In heap
roasting, the ore is hand-broken by Chinamen into small lumps before
being hoisted to the surface. From the landing on the surface it is run
out on long tracks under sheds, dumped around a loose brick flue and on
a few sticks of wood formed in the shape of a V, which runs to the flues
to give a draught. Layers of brush are put on at intervals through the
pile. The smaller lumps are placed in the core of the heap, the larger
lumps thrown upon them, and 40 tons of tank residues thrown over all to
exclude excess of air; 500 lb. of salt is then distributed through the
pile, and it is then set afire. After well alight the draught-holes are
closed up, and the pile is left to burn, which it does for six months.
At the expiration of that time the pile is broken into and sorted, the
imperfectly roasted ore is returned to a fresh roast-heap, and the rest
trammed to the


LEACH-VATS.

These are 50 in number, 10 having been recently added. The first 40 are
four feet by six feet and four feet deep, the remaining 10 twice as
large. About two tons of burnt ore is put in the small vats (twice as
much in the larger ones), half the vats being tilled at one time, and
then enough cold water is turned in to cover the ore. Steam is then
injected beneath the ore, thus boiling the water. After boiling for some
time, the steam is turned off and the water allowed to go cold. The
water, which after the boiling process turns to a dark red color, is
then drawn off. This water carries the copper in a state of solution.
The ore is then boiled a second time, after which the tank residues are
thrown out and water kept sprinkling over them. This water collects the
copper still left in the residues, and is then run into a reservoir, and
from the reservoirs still further on into settling tanks, previous to


PRECIPITATION,

and is then conducted through a system of boxes filled with scrap iron,
thus precipitating the copper.

The richer copper liquors which have been drawn from the tanks fire not
allowed to run in with that which comes from the dump heaps. This liquor
is also run into settling tanks, and from them pumped into four large
barrels, mounted horizontally on friction rollers, to which a very slow
motion is given. These barrels are 18 feet long and six feet six inches
deep outside measure. They are built very strongly, and are water-tight.
Ten tons of scrap iron are always kept in each of these barrels, which
are refilled six times daily, complete precipitation being effected in
less than four hours. Each barrel is provided with two safety valves,
inserted in the heads, which open automatically to allow the escape of
gas and steam. The precipitation of the copper in the barrels forms
copper cement. This cement is discharged from the barrels on to screens
which hold any lumps of scrap iron which may be discharged with the
cement. It is then dried by steam, after which it is conveyed into
another tank, left to cool, and then placed in bags ready for shipment,
as copper cement. The building in which the liquor is treated is the
mill part of the property, from which they send out 42 tons monthly of
an average of 85 per cent, of copper cement, this being the average
yield of the mine.

There are 23 white men and 40 Chinamen employed at the mine and the
mill. There are also several wood choppers, etc., on the company's
pay-roll. Eight months' supply of ore is always kept on hand, there
now being 12,000 tons roasting. The mine is now paying regular monthly
dividends, and everything argues well for the continuance of the same.

       *       *       *       *       *




SIR WILLIAM THOMSON'S PILE.


The Thomson pile, which is employed with success for putting in action
the siphon recorder, and which is utilized in a certain number of cases
in which an energetic and constant current is needed, is made in two
forms. We shall describe first the one used for demonstration. Each
element of this (Fig. 1) consists of a disk of copper placed at the
bottom of a cylindrical glass vessel, and of a piece of zinc in the form
of a grating placed at the upper part, near the surface of the solution.
A glass tube is placed vertically in the solution, its lower extremity
resting on the copper. Into this tube are thrown some crystals of
sulphate of copper, which dissolve in the liquid, and form a solution of
a greater density than that of the zinc alone, and which, consequently,
cannot reach the zinc by diffusion. In order to retard the phenomenon of
diffusion, a glass siphon containing a cotton wick is placed with one of
its extremities midway between the copper and zinc, and the other in
a vessel outside the element, so that the liquid is sucked up slowly
nearly to its center. The liquid is replaced by adding from the top
either water or a weak solution of sulphate of zinc.

[Illustration: FIG. 1.--THE THOMSON PILE.(Type for demonstration.)]

The greater part of the sulphate of copper that rises through the liquid
by diffusion is carried off by the siphon before reaching the zinc, the
latter being thus surrounded with an almost pure solution of sulphate
of copper having a slow motion from top to bottom. This renewal of the
liquid is so much the more necessary in that the saturated solution of
sulphate of copper has a density of 1.166, and the sulphate of zinc
one of 1.445, There would occur, then, a mixture through inversion of
densities if the solution were allowed to reach a too great amount of
saturation, did not the siphon prevent such a phenomenon by sucking up
the liquid into the part where the mixture tends to take place. The
chemical action that produces the current is identical with that of the
Daniell element.

In its application, this pile is considerably modified in form
and arrangement. Each element (Fig 2) consists of a flat wooden
hopper-shaped trough, about fifty centimeters square, lined with sheet
lead to make it impervious. The bottom is covered with a sheet of copper
and above this there is a zinc grate formed of closely set bars that
allow the liquid to circulate. This grate is provided with a rim which
serves to support a second similar element, and the latter a third,
and soon until there are ten of the elements superposed to form series
mounted for tension. The weight of the elements is sufficient to secure
a proper contact between the zinc and copper of the elements placed
beneath them, such contact being established by means of a band of
copper cut out of the sheet itself, and bent over the trough.

[Illustration: FIG. 2.--THE THOMSON PILE. (Siphon Recorder Type.)]

On account of the large dimensions of the elements, and the proximity
of the two metals, a pile is obtained whose internal resistance is very
feeble, it being always less than a tenth of an ohm when the pile is
in a good state, and the electromotive force being that of the Daniell
element--about 1 08 volts.

Sometimes the zinc is covered with a sheet of parchment which more
thoroughly prevents a mixture of the liquids and a deposit of copper on
the zinc. But such a precaution is not indispensable, if care be taken
to keep up the pile by taking out some of the solution of sulphate of
zinc every day, and adding sulphate of copper in crystals. If the pile
is to remain idle for some time, it is better to put it on a short
circuit in order to use up all the sulphate of copper, the disappearance
of which will be ascertained by the loss of blue color in the liquid. In
current service, on the contrary, a disappearance of the blue color will
indicate an insufficiency of the sulphate, and will be followed by a
considerable reduction in the effects produced by the pile.

The great power of this pile, and its constancy, when it is properly
kept up, constitute features that are indispensable for the proper
working of the siphon recorder--the application for which it was more
especially designed.

This apparatus has been also employed under some circumstances for
producing an electric light and charging accumulators; but such
applications are without economic interest, seeing the enormous
consumption of sulphate of copper during the operation of the pile.
The use of the apparatus is only truly effective in cases where it is
necessary to have, before everything else, an energetic and exceedingly
constant current.--_La Nature_.

       *       *       *       *       *




SIEMENS' TELEMETER


The accompanying cut illustrates a telemeter which was exhibited at the
Paris Exhibition of Electricity, and which is particularly interesting
from the fact that it is the first apparatus of this kind. It will be
remembered that the object of a telemeter is to make known at any moment
whatever the distance of a movable object, and that, too, by a direct
reading and without any calculation. In Mr. Siemens' apparatus the
problem is solved in the following manner:

The movable object (very often a vessel) is sighted from two different
stations--two points of the coast, for example--by two different
observers. The sighting is done with two telescopes, A1 and A2, which
the observers revolve around a vertical axis by means of two winches, K1
and K2, that gear with two trains of clockwork. There is thus constantly
formed a large triangle, having for its apices the movable point sighted
and the vertical axes, A1 and A2, of the two telescopes. On another
hand, at a point situated between the two telescopes, there is a table,
T T, that carries two alidades, a1v1, and a2v2, movable around their
vertical axes, a1 and a2. The line, a1 a2, that joins these axes is
parallel with that which joins the axes of the two telescopes; and the
alidades are connected electrically with the telescopes by a system
such that each alidade always moves parallel with the telescope that
corresponds to it. It follows from this that the small triangle that
has for apices, a1 a2, and the crossing point of the two alidades will
always be like the large triangle formed by the line that joins the
telescopes and the two lines of vision. If, then, we know the ratio of
a1, a2 to A1 A2, it will suffice to measure on one of the alidades the
distance from its axis to the point of crossing in order to know the
distance from the movable object to the axis of the corresponding
telescope. If the table, T T, be covered with a chart giving the space
over which the ship is moving, so that a1 and a2 shall coincide with the
points which A1 and A2 represent, the crossing of the threads of the
alidades will permit of following on the chart all the ship's movements.
In this way there maybe had a powerful auxiliary in coast defence; for
all the points at which torpedoes have been sunk may be marked on the
chart, and, as soon as the operator at the table finds, by the motion
of the alidades, that the ship under observation is directly over a
torpedo, he will be able to fire the latter and blow the enemy up.
During this time the two observers at A1 and A2 have only to keep their
telescopes directed upon the vessel that it has been agreed upon to
watch.

[Illustration: SIEMENS' ELECTRIC TELEMETER]

In order to obtain a parallelism between the motion of the alidades and
that of the corresponding telescopes, the winch of each of the latter,
while putting its instrument in motion, also sets in motion a Siemens
double-T armature electromagnetic machine. One of the wires of the
armature of this machine, connected to the frame, is always in
communication with the ground at E1 (if we consider, for example, the
telescope to the left), and the other ends in a spring that alternately
touches two contacts. One of these contacts communicates with the
wire, L1 and the other with the wire, L3, so that, when the machine is
revolving, the currents are sent alternately into L1 and L3. These two
latter wires end in a system of electro magnets, M1, provided with a
polarized armature. The motions of the latter act, through an anchor
escapement, upon a system of wheels. An axle, set in motion by the
latter, revolves one way or the other, according to the direction of the
telescope's motions. This axle is provided with an endless screw that
gears with a toothed sector, and the latter controls the rotatory axis
of the alidade. The elements of the toothed wheels and the number of
revolutions of the armature for a given displacement of the telescope
being properly calculated, it will be seen that the alidade will be able
to follow all the movements of the latter.

When it is desired to place one of the telescopes in a given position
(its position of zero, for example), without acting on the alidade,
it may be done by acting directly on the telescope itself without the
intermedium of the winch. For such purpose it is necessary to interrupt
communication with the mechanism by pressing on the button, q. If the
telescope be turned to one side or the other of its normal position,
in making it describe an angle of 90°, it will abut against stops, and
these two positions will permit of determining the direction of the
base.

The alidades themselves are provided with a button which disengages the
toothed sector from the endless screw, and permits of their being
turned to a mark made on the table. A regulating screw permits of this
operation being performed very accurately. In what precedes, we have
supposed a case in which the movable point is viewed by two observers,
and in which the table, T T, is stationed at a place distant from them.
In certain cases only two stations are employed. One of the telescopes
is then placed over its alidade and moves with it; and the apparatus
thus comprehends only a system of synchronous movements.

This telemeter was one of the first that was tried in our military
ports, and gave therein most satisfactory results. The maneuver of the
winch, however, requires a certain amount of stress, and in order that
the sending of the currents shall be regular, the operator must turn it
very uniformly. This is a slight difficulty that has led to the use
of piles, instead of the magneto-electric machine, in the apparatus
employed in France. With such substitution there is need of nothing more
than a movable contact that requires no exertion, and that may be guided
by the telescope itself.--_La Lumière Electrique_.

       *       *       *       *       *




PHYSICS WITHOUT APPARATUS.


_Experiment in Static Electricity_.--Take a pipe--a common clay one
costing one cent--and balance it carefully on the edge of a goblet, so
that it will oscillate freely at the least touch, like the beam of a
scales. This being done, say to your audience: "Here is a pipe placed
on the edge of a goblet; now the question is to make it fall without
touching it, without blowing against it, without touching the glass,
without agitating the air with a fan, and without moving the supporting
table"

[Illustration: CLAY PIPE ATTRACTED BY AN ELECTRIFIED GOBLET.]

The problem thus proposed may be solved by means of electricity. Take a
goblet like the one that supports the pipe, and rub it briskly against
your coat sleeve, so as to electrify the glass through friction. Having
done this, bring the goblet to within about a centimeter of the pipe
stem. The latter will then be seen to be strongly attracted, and will
follow the glass around and finally fall from its support.

This curious experiment is a pretty variation of the electric pendulum;
and it shows that pipe-clay--a very bad conductor of electricity--favors
very well the attraction of an electrified body.

Tumblers or goblets are to be found in every house, and a clay pipe
is easily procured anywhere. So it would be difficult to produce
manifestations of electricity more easily and at less expense than by
the means here described.--_La Nature_.

       *       *       *       *       *




THE CASCADE BATTERY.

[Footnote: Lately read before the Society of Telegraph Engineers and
Electricians.]

By F. HIGGINS.


The battery which I have brought here to-night to introduce to your
notice is of the circulating kind, in which the alimentary fluid
employed passes from cell to cell by gravitation, and maintains the
action of the battery as long as it continues to flow. It cannot,
of course, compare with such abundant sources of electricity as
dynamo-electric machines driven by steam power, but for purposes in
which a current of somewhat greater volume and constancy than that
furnished by the ordinary voltaic batteries is required, it will, I
believe, be found in some cases useful. A single fluid is employed, and
each cell is provided with an overflow spout.

The cells are arranged upon steps, in order that the liquid may flow
from the cell on the topmost step through each successive cell by
gravitation [specimen cells were on the table before the audience] to
the reservoir at the bottom. The top and the bottom reservoirs are of
equal capacity, and are fitted with taps. The topmost tap is used to
regulate the flow of the solution, and the bottom one to draw it off. In
each cell two carbon plates are suspended above a quantity of fragments
of amalgamated zinc. The following is a sectional drawing of the
arrangement of the cell:

[Illustration]

A copper wire passes down to the bottom of the cell and makes connection
with the mercury; this wire is covered with gutta-percha, except where
immersed in the mercury. The pores of the carbon plates are filled
with paraffin wax. This battery was first employed for the purpose of
utilizing waste solution from bichromate batteries, a great quantity of
which is thrown away before having been completely exhausted. This waste
is unavoidable, in consequence of the impossibility of permitting such
batteries, when employed for telegraphic purposes, to run until complete
exhaustion or reduction of the solutions has been effected; therefore
some valuable chemicals have to be sacrificed to insure constancy in
working. The fragments of zinc in this cell were also the remains of
amalgamated zinc plates from the bichromate batteries, and the mercury
which is employed for securing good metallic connection is soon
augmented by that remaining after the dissolution of the zinc. It will
therefore be seen that not only the solution, but also the zinc and
mercury remnants of bichromate batteries are utilized, and at the same
time a considerable quantity of electricity is generated. The cells are
seven inches deep and six inches wide, outside, and contain about a
quart of solution in addition to the plates. The battery which I employ
regularly, consisting of 18 cells, is at present working nine permanent
current Morse circuits, which previously required 250 telegraphic
Daniell cells to produce the same effect, and is capable of working at
least ten times the number of circuits which I have mentioned; but as we
do not happen to have any more of such permanent current Morse circuits,
we are unable to make all the use possible of the capabilities of the
battery. The potential of one cell is from 1.9 to 2 volts with strong
solution, and the internal resistance varies from 0.108 to 0.170 of an
ohm with cells of the size described. In order to test the constancy of
the battery, a red heat was maintained in a platinum-iridium wire by the
current for six weeks, both day and night.

The absence or exhaustion of the zinc in any one cell in a battery is
indicated by the appearance of a red insoluble chromic salt of mercury,
in a finely divided state, floating in the faulty cell. It is then
necessary to drop in some pieces of zinc. The state of the zinc supply
may also be ascertained at any time by feeling about in the cells with a
stick. When not required, the battery may be washed by simply charging
the top reservoir with water, and leaving it to circulate in the usual
manner, or the solution may be withdrawn from each cell by a siphon. A
very small flow of the solution is sufficient to maintain the required
current for telegraphic working, but if the flow be stopped altogether
for a few hours, no difference is observed in the current, although when
the current is required to be maintained in a conductor of a few ohms
resistance, as in heating a platinum wire, it is necessary that the
circulation be maintained [heating a piece of platinum ribbon]. The
battery furnishing the current for producing the effect you now see is
of five cells, and as that number is reduced down to two, you see a glow
still appears in the platinum. The platinum strip employed was 5 inches
long and 1/8 inch wide, its resistance being 0.42 ohm, cold. That gives
an idea of the volume of current flowing. I have twelve electro magnets
in printing instruments joined up on the table, and [joining up the
battery] you see that the two cells are sufficient to work them. The
twelve electro-magnets are being worked (by the two cells) in multiple
arc at the same time. The current from the cells which heated the
platinum wire is amply sufficient to magnetize a Thomson recorder. I
have maintained five inches of platinum ribbon in a red hot state for
two hours, in order to make sure that the battery I was about to bring
before you was in good order. The cost of working such a battery when
waste solution cannot be obtained, and it is necessary to use specially
prepared bichromate solution, is about 2¼d. per cell per day, with a
current constantly active in a Thomson recorder circuit, or a resistance
of 1½ ohms per cell; but if only occasionally used, the same quantity of
solution will last several weeks.

A comparison of this with another form of constant battery, the Daniell,
as used in telegraphy, shows that six of these cells, with a total
electromotive force of 12 volts and an internal resistance of 0.84 of
an ohm, cannot be replaced by less than 71 batteries of 10 cells each,
connected in multiple arc, or for quantity. This result, however large
it may appear, is considerably below that which may be obtained when
working telegraphic lines. A current of 0.02 weber, or ampere, will work
an ordinary sounder or direct writing Morse circuit; the cascade battery
is capable of working 100 such circuits at the same time, while the
combined resistance of that number of lines would not be below that in
which it is found that the battery is constant in action.

Objection may be made to the arrangement of the battery on the score of
waste of zinc by local action, because of the electro positive metal
being exposed to the chromic liquid; but if the battery be out of action
and the circulation stopped, the zinc amalgam is protected by the
immobility of the liquid and the formation of a dense layer of sulphate
of zinc on its surface. When in action, that effect is neutralized from
the fact that carbon in chromic acid is more highly electro-negative
than the chromate of mercury formed upon the zinc amalgam, and which
appears to be the cause of the dissolution of the zinc even when
amalgamated in the presence of chromic acid. The solution may be
repeatedly passed through the battery until the absence of the
characteristic warmth of color of chromic acid indicates its complete
exhaustion. During a description before the Society of thermo-electric
batteries some time ago, Mr. Preece mentioned that five of the
thermopiles which were being tried at the Post-Office were doing the
work of 2,535 of the battery cells previously employed. Thirty of
the cascade cells would have about the same potential as five such
thermopiles, but would supply three and a half times the current, and be
capable of doing the work of 8,872 cells if employed upon the universal
battery system in the same manner as the thermo batteries referred to.

Although this battery will do all that is required for a Thomson
recorder or a similar instrument much more cheaply in this country than
the tray battery, and with half the number of cells, I do not think it
would be the case in distant countries, on account of the difficulty and
cost of transport. A solid compound of chromic and sulphuric acids could
be manufactured which would overcome this difficulty, if permanent
magnetic fields for submarine telegraphic instruments continue to be
produced by electric vortices. In conclusion, and to enable comparisons
to be made, I may mention that the work this battery is capable of
performing is 732,482 foot pounds, at a total cost of 1s. 6d.

       *       *       *       *       *


[FROM THE SCHOOL JOURNAL.]




PERFECTLY LOVELY PHILOSOPHY.


CHARACTERS: Laura and Isabel, dressed very stylishly, both with hats on.
Enter hand in hand.

_Laura_. My dear Isabel, I was so afraid you would not come. I waited
at that horrid station a full half hour for you. I went there early on
purpose, so as to be sure not to miss you.

_Isabel_. Oh, you sweet girl!

_L_. Now, sit right down; you must be tired. Just lay your hat there on
the table, and we'll begin to visit right off. (_Both lay their hats on
the table and stand near by_.)

_I_. And how have you been all the ages since we were together at
Boston?

_L_. Oh, well, dear; those were sweet old school days, weren't they. How
are you enjoying yourself now? You wrote that you were taking lessons in
philosophy. Tell me how you like it. Is it real sweet?

_I_ Oh, those I took in the winter were perfectly lovely! It was about
science, you know, and all of us just doled on science.

_L_. It must have been nice. What was it about?

_I_. It was about molecules as much as anything else, and molecules are
just too awfully nice for anything. If there's anything I really enjoy,
it's molecules.

_L_. Oh, tell me about them, dear. What are molecules?

_I_. They are little wee things, and it takes ever so many of them, you
know. They are so sweet! Do you know, there isn't anything but that's
got a molecule in it. And the professors are so lovely! They explained
everything so beautifully.

_L_. Oh, how I'd like to have been there!

_I_. You'd have enjoyed it ever so much. They teach protoplasm, too,
and if there's one thing that is too sweetly divine, it's protoplasm. I
really don't know which I like best, protoplasm or molecules.

_L_. Tell me about protoplasm. I know I should adore it!

_I_. 'Deed you would. It's just too sweet to live. You know it's about
how things get started, or something of that kind. You ought to have
heard the professors tell about it. Oh. dear! (_Wipes her eyes with
handkerchief_) The first time he explained about protoplasm there wasn't
a dry eye in the room. We all named our hats after the professors. This
is a Darwinian hat. You see the ribbon is drawn over the crown this way
(_takes hat and illustrates_), and caught with a buckle and bunch of
flowers. Then you turn up the side with a spray of forget me-nots.

_L_. Oh, how utterly sweet! Do tell me some more of science. I adore it
already.

_I_. Do you, dear? Well, I almost forgot about differentiation. I am
really and truly positively in love with differentiation. It's different
from molecules and protoplasms, but it's every bit as nice. And our
professor! You should hear him enthuse about it; he's perfectly bound up
in it. This is a differentiation scarf--they've just come out. All
the girls wear them--just on account of the interest we take in
differentiation.

_L_. What is it, anyway?

_I_. Mull trimmed with Languedoc lace, but--

_L_. I don't mean that--the other.

_I_. Oh, differentiation! That's just sweet. It's got something to
do with species. And we learn all about ascidians, too. They are the
divinest things! If I only had an ascidian of my own! I wouldn't ask
anything else in the world.

_L_. What do they look like, dear? Did you ever see one?

_I_. Oh, no; nobody ever did but the poor dear professors; but they're
something like an oyster with a reticule hung on its belt. I think they
are just _too_ lovely for anything.

_L_. Did you learn anything else besides?

_I_. Oh, yes. We studied common philosophy, and logic, and metaphysics,
and a lot of those ordinary things, but the girls didn't care anything
about those. We were just in ecstasies over differentiations, and
molecules, and the professor, and protoplasms, and ascidians. I don't
see why they put in those common branches; we couldn't hardly endure
them.

_L_. (_Sighs_.) Do you believe they'll have a course like that next
year?

_I_. I think may be they will.

_L_. Dear me! There's the bell to dress for dinner. How I wish I could
study those lovely things!

_I_. You must ask your father if you can't spend the winter in Boston
with me. I'm sure there'll be another course of Parlor Philosophy next
winter. But how dreadful that we must stop talking about it now to dress
for dinner! You are going to have company, you said; what shall you
wear, dear?

_L_. Oh, almost anything. What shall you?

(_Exeunt arm in arm_.)

       *       *       *       *       *




THE PROPOSED DUTCH INTERNATIONAL COLONIAL AND GENERAL EXPORT EXHIBITION.


The Amsterdam International Exhibition, the opening of which has been
fixed for May 1, 1883, is now in way of realization. This exhibition
will present a special interest to all nations, and particularly to
their export trade. Holland, which is one of the great colonial powers,
proposes by means of this affair to organize a competition between the
various colonizing nations, and to contribute thus to a knowledge of
the resources of foreign countries whose richness of soil is their
fundamental power.

The executive committee includes the names of some of the most prominent
persons of the Netherlands: M. Cordes, president; M. de Clercq,
delegate; M. Kappeyne van di Coppello, secretary; and M. Agostini,
commissary general.

[Illustration: PLAN OF THE DUTCH INTERNATIONAL EXHIBITION.

   1. Exhibition Palace.
   2. Netherlands Colonial Exhibition.
   3. Fine Arts.
   4. Annexes for Agricultural Machines, etc.
   5. Machines, Materials, etc.
   6. Concert Theater.
   7. Panorama.
   8. Jury Pavilion.
   9. Royal Pavilion.
  10. Committee Pavilion.
  11. International Society's Pavilion.
  12. Restaurant and Café.
  13. Music Kiosque and Electric Pharos.
  14. German Restaurant.
  15. Dutch Restaurant.
  16. English Restaurant.
  17. French Restaurant.
  18. Aquarium and Rockwork.
]

The exhibition will consist of five great divisions, to wit: 1. A
Colonial exhibition. 2. A General Export exhibition. 3. A Retrospective
exhibition of Fine Arts and of Arts applied to the Industries. 4.
Special exhibitions. 5. Lectures and Scientific Reunions.

The colonial part forms the base of the exhibition, and will be devoted
to a comparative study of the different systems of colonization
and colonial agriculture, as well as of the manners and customs of
ultramarine peoples. In giving an exact idea of what has been done, it
will indicate what remains to be done from the standpoint of a general
development of commerce and manufactures. Such is the programme of the
first division.

The second division will include everything that relates to the export
trade.

The third division will be reserved for works of art dating back from
the most remote ages.

The fourth division will be devoted to temporary exhibitions, such as
those of horticultural and agricultural products, etc.

The fifth division will constitute the intellectual part, so to speak,
of the exhibition. It will be devoted to lectures, and to scientific
meetings for the discussion of questions relating to teaching, to the
arts, to the sciences, to hygiene, to international jurisprudence, and
to political economy. Questions of colonial economy will naturally
occupy the first rank.

As will be seen, the programme of this grand scheme organized by the
Netherlands government is a broad one; and, owing the experience
acquired in recent universal exhibitions, especially that of Paris in
1878, very happy results may be expected from it.

At present, we give an illustration showing the general plan of the
exhibition. In future, in measure as the work proceeds, we shall be able
to give further details.--_Le Genie Civil_.

       *       *       *       *       *




NEW METHOD OF DETECTING DYES ON YARNS AND TISSUES.

By JULES JOFFRE.


The reagents employed are a solution of caustic potassa in ten parts
of water; hydrochloric acid diluted with an equal bulk of water, or
occasionally concentrated; nitric acid, ammonia, ferric sulphate, and
a concentrated solution of tin crystals. The most convenient method of
operating is to steep small portions of the cloth under examination in a
little of the reagent placed at the bottom of a porcelain capsule. The
bits are then laid on the edge of the capsule, when the changes of color
which they have undergone may be conveniently observed. It is useful to
submit to the same reagents simultaneously portions of cloth dyed in a
known manner with the wares which are suspected of having been used in
dyeing the goods under examination.


RED COLORS.

By the action of caustic potassa, the reds are divided into four groups:
1, those which turn to a violet or blue; 2, those which turn brown;
3, those which are changed to a light yellow or gray; 4, those which
undergo little or no change.

The first group comprises madder, cochineal, orchil, alkanet, and
murexide. Madder reds are turned to an orange by hydrochloric acid,
while the three next are not notably affected. Cochineal is turned by
the potassa to a violet-red, orchil to a violet-blue, and alkanet to a
decided blue. Lac-dye presents the same reactions as cochineal, but
has less brightness. Ammoniacal cochineal and carmine may likewise be
distinguished by the tone of the reds obtained.

A characteristic of madder reds is that, after having been turned yellow
by hydrochloric acid, they are rendered violet on treatment with milk
of lime. A boiling soap-lye restores the original red, though somewhat
paler. Artificial alizarine gives the same reaction. Turkey-reds,
however, are quite unaffected by acid. Garancine and garanceux reds, if
treated first with hydrochloric acid and then with milk of lime, turn to
a dull blue.

Madder dyes are sometimes slow in being turned to a violet by potassa,
and this shade when produced is often brownish. They might thus be
confounded with the dyes of the fourth group, i.e., rosolic acid,
coralline, eosine, and coccine. None of these colors gives the
characteristic reaction with milk of lime and boiling soap-lye. If
plunged in milk of lime, they resume their rose or orange shades, while
the madder colors become violet. Murexide is turned, by potassa, gray
in its light shades and violet in its dark ones. It might, then, be
confounded with orchil, but it is decolorized by hydrochloric acid,
which leaves orchil a red. Moreover, it is turned greenish by stannous
chloride.

A special character of this dye (murexide) is the presence of mercury,
the salts of which serve as mordants for fixing it, and may be detected
by the ordinary reagents.

The second group comprises merely sandal wood or sanders red, which
turns to a brown. On boiling it with copperas it becomes violet, while
on boiling with potassium dichromate it changes to a yellowish brown.

The third group includes safflower, magenta, and murexide (light
shades). If the action of the potassa is prolonged the (soft) red woods
enter into this group. Safflower turns yellow by the action of potassa,
and the original rose shade is not restored by washing with water.
Hydrochloric acid turns it immediately yellow. Citric acid has no
action. Magenta is completely decolorized by potassa, but a prolonged
washing in water reproduces the original shade. This reaction is common
to many aniline colors. These decolorations and recolorations are easily
produced in dark shades, while in very light shades they are less easily
observed, because there is always a certain loss of color. Stannous
chloride turns magenta reds to a violet. Hydrochloric acid renders them
yellowish brown (afterward greenish?). Water restores the purple red
shade.

The fourth group comprises saffranine, azo-dinaphthyldiamine, rosolic
acid, coralline, pure eosine and cosine modified by a salt of lead,
coccina, artificial ponceau, and red-wood.

Saffranine is detected by the action of hydrochloric acid, which turns
it to a beautiful blue; the red color is restored by washing in water.
Azo-dinaphthyl diamine is recognized by its peculiar orange cast, and is
turned by hydrochloric acid to a dull, dirty violet. Rosolic acid and
coralline, as well as eosine, are turned by hydrochloric acid to an
orange-yellow: the two former are distinguished from eosine by their
shade, which inclines to a yellow. Potassa turns rosolic acid and
coralline from an orange-red to a bright red, while it produces no
change in eosine. If the action of potassa is prolonged, modified eosine
is blackened in consequence of the decomposition of the wool, the
sulphur of which forms lead sulphide. Coccine becomes of a light
lemon-yellow on treatment with hydrochloric acid. Washing with water
restores the original shade. It affords the same reactions as eosine,
but its tone is more inclined to an orange.

Artificial ponceau does not undergo any change on treatment with
hydrochloric acid, and resists potash. Red wood shades are turned toward
a gooseberry-red by hydrochloric acid, especially if strong. This last
reaction not being very distinct, red-wood shades might be mistaken
for those of artificial ponceau but for the superior brightness of the
latter. If the action of potassa is prolonged, the red-wood shades
are decolorized, and a washing with water then bleaches the tissue.
Rocelline affords the same reactions as artificial ponceau, but if
steeped in a concentrated solution of stannous chloride it is in time
completely discharged, which is not the case with artificial ponceau.


VIOLET COLORS.

Violets are divided into two groups: those affected by potassa, and
those upon which it has no action. The first group embraces logwood,
orchil, alkanet, and aniline violets, including under the latter term
Perkin's violet, (probably the original "mauve"), dahlia, Parme or
magenta violet, methyl, and Hofmann's violets. The action of potassa
gives indications for each of these violets. Logwood violet is browned;
that of orchil, if slightly reddish, is turned to a blue-violet; that of
alkanet is modified to a fine blue. Lastly, Perkin's mauve, dahlia, and
methyl violet become of a grayish brown, which may be re-converted into
a fine violet by washing in abundance of water. When the shades are
very heavy, this grayish brown is almost of a violet-brown, so that the
violets might seem to be unaltered.

The action of hydrochloric acid distinguishes these colors better still
if the aid of ammonia is called in for two cases.

The acid turns logwood violet to a fine red, and equally reddens orchil
violet. But the two colors cannot be confounded, first, because the two
violet shades are very distinct, that of orchil being much the brighter;
and secondly, because ammonia has no action on logwood violet, while it
turns orchil violet, if at all reddish, to a blue shade. Hydrochloric
acid, whether dilute or concentrated, is without action on alkanet
violet. If the acid is dilute, it is equally without action on Perkin's
violet and dahlia. If it is strong, it turns them blue, and even green
if in excess. Hofmann's violet turns green even with dilute acid, but
prolonged washing restores the original violet shade. Dahlia gives a
more blue shade than Perkin's mauve. The action of acid is equally
characteristic for methyl violet. It becomes green, then yellow. Washing
in water re-converts it first to a green, and then to a violet.

The second group includes madder violet, cochineal violet, and the
compound violet of cochineal and extract of indigo. These three dyes are
thus distinguished: Hydrochloric acid turns the madder violet-orange,
slightly brownish, or a light brown, and it affords the characteristic
reaction of the madder colors described above under reds. Cochineal
violets are reddened. Sometimes they are decolorized, and become finally
yellow, but do not pass through a brown stage.

The compound violet of cochineal and extract of indigo presents this
characteristic reaction, that if boiled with very weak solution of
sodium carbonate the liquid becomes blue, rather greenish, while the
cloth becomes a vinous-red--_Moniteur Scientifique.--Chem. News._

       *       *       *       *       *




CHEVALET'S CONDENSO-PURIFIER FOR GAS.


The condenso-purifier shown in the accompanying cut operates as
follows: Water is caused to flow over a metallic plate perforated with
innumerable holes of from one to three millimeters in diameter, and
then, under this disk, which is exactly horizontal, a current of gas is
introduced. Under these circumstances the liquid does not traverse the
holes in the plate, but is supported by the gas coming in an opposite
direction. Provided that the gas has sufficient pressure, it bubbles up
through the water and becomes so much the more divided in proportion as
the holes are smaller and more numerous.

The gas is washed by traversing the liquid, and freed from the tar and
coal-dust carried along with it; while, at the same time, the ammonia
that it contains dissolves in the water, and this, too, so much the
better the colder the latter is. This apparatus, then, permits of
obtaining two results: a mechanical one, consisting in the stoppage of
the solid matters, and a chemical one, consisting in the stoppage of the
soluble portions, such as ammonia, sulphureted hydrogen, and carbonic
acid.

[Illustration: FIG. 1.--CONDENSO-PURIFIER FOR GAS. (Elevation.)]

The condenso-purifier consists of three perforated diaphragms, placed
one over the other in rectilinear cast-iron boxes. These diaphragms are
movable, and slide on projections running round the interior of the
boxes. In each of the latter there is an overflow pipe, g, that runs to
the box or compartment below, and an unperforated plate, f, that slides
over the diaphragm so as to cover or uncover as many of the holes as may
be necessary. A stream of common water runs in through the funnel, e,
over the upper diaphragm, while the gas enters the apparatus through the
pipe, a, and afterward takes the direction shown by the arrows.
Reaching the level of the overflow, the water escapes, fills the lower
compartment, covers the middle diaphragm, then passes through the second
overflow-pipe to cover the lower diaphragm, next runs through the
overflow-pipe of the third diaphragm on to the bottom of the purifier,
and lastly makes its exit, through a siphon. A pressure gauge, having an
inlet for the gas above and below, serves for regulating the pressure
absorbed for each diaphragm, and which should vary between 0.01 and
0.012 of a meter.

The effect of this purifier is visible when the operation is performed
with an apparatus made externally of glass. The gas is observed to enter
in the form of smoke under the first diaphragm, and the water to become
discolored and tarry. When the gas traverses the second diaphragm, it is
observed to issue from the water entirely colorless, while the latter
becomes slightly discolored, and finally, when it traverses the third
diaphragm, the water is left perfectly limpid.

Two diaphragms have been found sufficient to completely remove the solid
particles carried along by the gas, the third producing only a chemical
effect.

This apparatus may replace two of the systems employed in gas works: (1)
mechanical condensers, such as the systems of Pelouze & Audouin, and
of Servier; and (2) scrubbers of different kinds and coke columns.
Nevertheless, it is well to retain the last named, if the gas works have
them, but to modify their work.

[Illustration: FIG. 2.--PLAN VIEW WITH BY-PASS.]

This purifier should always be placed directly after the condensers, and
is to be supplied with a stream of pure water at the rate of 50 liters
of water per 1,000 cubic meters of gas. Such water passes only once into
the purifier, and issues therefrom sufficiently rich in ammonia to be
treated.

If there are coke columns in the works, they are placed after the
purifier, filled with wood shavings or well washed gravel, and then
supplied with pure cold water in the proportion stated above. The water
that flows from the columns passes afterward into the condenso-purifier,
where it becomes charged with ammonia, and removes from the gas the tar
that the latter has carried along, and then makes its exit and goes to
the decanting cistern.

In operating thus, all the remaining ammonia that might have escaped the
condenso-purifier is removed, and the result is obtained without pumps
or motor, with apparatus that costs but little and does not occupy much
space. The advantages that are derived from this, as regards sulphate
of ammonia, are important; for, on treating ammoniacal waters with
condensers, scarcely more than four to five kilogrammes of the sulphate
are obtained per ton of coal distilled, while by washing the gas
perfectly with the small quantity of water indicated, four to five
kilogrammes more can be got per 1,000 kilogrammes of coal, or a total of
eight to ten kilogrammes per ton.

When the gas is not washed sufficiently, almost all of the ammonia
condenses in the purifying material.

The pressure absorbed by the condenso purifier is from ten to twelve
millimeters per washing-diaphragm. In works that are not provided with
an extractor, two diaphragms, or even a single one, are employed when it
is desired simply to catch the tar.

The apparatus under consideration was employed in the St. Quentin
gas works during the winter of 1881-1882, without giving rise to any
obstruction; and, besides, it was found that by its use there might be
avoided all choking up of the pipes at the works and the city mains
through naphthaline.

In cases of obstruction, it is very easy to take out the perforated
diaphragms; this being done by removing the bolts from the piece that
holds the register, f, and then removing the diaphragm and putting in
another. This operation takes about ten minutes. The advantages of such
a mounting of the diaphragms is that it allows the gas manufacturer to
employ (and easily change) the number of perforations that he finds best
suited to his needs.

These apparatus are constructed for productions of from 1,000 to 100,000
cubic meters of gas per twenty four hours. They have been applied
advantageously in the washing of smoke from potassa furnaces, in order
to collect the ammonia that escapes from the chimneys. In one of such
applications, the quantity of gas and steam washed reached a million
cubic meters per twenty-four hours.--_Revue Industrielle._

       *       *       *       *       *




ARTIFICIAL IVORY.


It is said that artificial ivory of a pure white color and very durable
has been manufactured by dissolving shellac in ammonia, mixing the
solution with oxide of zinc, driving off ammonia by heating, powdering,
and strongly compressing in moulds.

       *       *       *       *       *




CREOSOTE IMPURITIES.

[Footnote: Read at the meeting of the American Pharmaceutical
Association held at Niagara Falls. 1882.]

By Prof. P. W. BEDFORD.


The object of this query can be but one, namely, to inquire whether the
wood creosote offered for sale is a pure article, or not; and if not,
what is the impurity present?

The relative commercial value of the articles sold as coal tar creosote
and wood creosote disposes of the question as to the latter being
present in the former article, and we are quite certain that the cheap
variety is nothing more or less than a phenol or carbolic acid. Wood
creosote, it has been frequently stated, is adulterated with coal tar
creosote, or phenol. The object of my experiments has been to prove the
identity of wood creosote and its freedom from phenol. The following
tests are laid down in various works as conclusive evidence of its
purity, and each has been fully tried with the several samples of wood
creosote to prove their identity and purity, and also with phenol, sold
as commercial creosote or coal tar creosote, and for comparison with
mixtures of the two, that even small percentages of admixture might be
identified, should such exist in the wood creosote of the market.

The following tests were used:

1. Equal volumes of anhydrous glycerine and wood creosote make a turbid
mixture, separating on standing. _Phenol dissolves_. If three volumes
of water be added, the separation of the wood creosote is immediate.
_Phenol remains in permanent solution_.

2. One volume of wood creosote added to two volumes of glycerine; the
former is not dissolved, but separates on standing. _Phenol dissolves_.

3. Three parts of a mixture containing 75 per cent, of glycerine and
25 of water to 1 part of wood creosote show no increase of volume of
glycerine, and wood creosote separates. _Phenol dissolves, and forms
a clear mixture_. Were any phenol present in the wood creosote, the
increase in the volume of the glycerine solution, if in a graduated
tube, would distinctly indicate the percentage of phenol present.

4. Solubility in benzine. Wood creosote entirely soluble. _Phenol is
insoluble_.

5. A 1 per cent, solution of wood creosote. Take of this 10 cubic
centimeters, add 1 drop of a test solution of ferric chloride; an
evanescent blue color is formed, passing quickly into a red color.
_Phenol gives a permanent blue color_.

6. Collodion or albumen with an equal bulk of wood creosote makes a
perfect mixture without coagulation. _Phenol at once coagulates into a
more or less firm mass or clot_.

7. Bromine solution with wood creosote gives a reddish brown
precipitate. _Phenol gives a white precipitate_.

All tests enumerated above were repeatedly tried with four samples of
wood creosote sold as such; one a sample of Morson's, one of Merck's,
one evidently of German origin, but bearing the label and capsule of an
American manufacturer, and one of unknown origin, but sold as beech-wood
creosote (German), and each proved to be _pure wood creosote_.

Two samples of commercial creosote which, from the low cost, were known
to be of coal tar origin gave the negative tests, showing that they were
phenol.

Corroborative experiments were made by mixing 10 to 20 per cent, of
phenol with samples of the beechwood creosote, but in every case each of
the tests named showed the presence of the phenol.

The writer on other occasions applied single tests (the collodion test)
to samples of beechwood creosote that he had an opportunity of procuring
small specimens of, and satisfied himself that they were pure. The
conclusion is that the wood creosote of the market of the present time
is in abundant supply, is of unexceptionable quality, and reasonable in
price, so that there is no excuse for the substitution of the phenol
commonly sold for it. When it is directed for use for internal
administration (the medicinal effect being entirely dissimilar), wood
creosote only should be dispensed.

The general sales of creosote by the pharmacist are in small quantities
as a toothache remedy, and phenol has the power of coagulating albumen,
which effectually relieves the suffering. Wood creosote does not
coagulate albumen, and is, therefore, not as serviceable. This is,
perhaps, the reason that it has become, in a great measure, supplanted
in general sale by the coal tar creosote, to say nothing of the argument
of a lower cost.

       *       *       *       *       *




REMEDY FOR SICK HEADACHE.


Surgeon Major Roehring, of Amberg, reports, in No. 32 of the _Allg. Med.
Centr. Zeit_., April 22, 1882, a case of headache of long standing,
which he cured by salicylate of sodium, which confirms the observations
of Dr. Oehlschlager, of Dantzig, who first contended that we possessed
in salicylic acid one of the most reliable remedies for neuralgia. This
cannot astonish us if we remember that the action of salicylic acid is,
in more than one respect, and especially in its influence on the nervous
centers, analogous to quinine.

While out with the troops on maneuver, Dr. Roehring was called to visit
the sixteen-year old son of a poor peasant family in a neighboring
village. The boy, who gave all evidences of living under bad hygienic
surroundings, but who had shown himself very diligent at school, had
been suffering, from his sixth year, several days every week from the
most intense headache, which had not been relieved by any of the many
remedies tried for this purpose. A careful examination did not reveal
any organic lesion or any cause for the pain, which seemed to be
neuralgic in character, a purely nervous headache. Roehring had just
been reading the observations of Oehlschlager, and knowing, from the
names of the physicians who had been already attending the poor boy,
that all the common remedies for neuralgia had been given a fair trial,
thought this a good opportunity to test the virtue of salicylate of
sodium. He gave the boy, who, in consequence of the severity of the
pain, was not able to leave his bed, ten grains of the remedy every
three hours, and was surprised to see the patient next day in his tent
and with smiling face. The boy admitted that he for years had not been
feeling so well as he did then. The remedy was continued, but in less
frequent doses, for a few days longer; the headache did not return.
Several months later Dr. Roehring wrote to the school-teacher of the
boy, and was informed that the latter had, during all this time,
been totally free of his former pain, that he was much brighter than
formerly, and evidently enjoying the best of health.

It may be worth while to give the remedy a more extensive trial, and the
more so as we are only too often at a loss what to do in stubborn cases
of so-called nervous headache.--_The Medical and Surgical Reporter_.

       *       *       *       *       *




SUNLIGHT AND SKYLIGHT AT HIGH ALTITUDES.


At the Southampton meeting of the British Association, Captain Abney
read a paper in which he called attention to the fact that photographs
taken at high altitudes show skies that are nearly black by comparison
with bright objects projected against them, and he went on to show that
the higher above the sea level the observer went, the darker the sky
really is and the fainter the spectrum. In fact, the latter shows but
little more than a band in the violet and ultraviolet at a height of
8,500 feet, while at sea-level it shows nearly the whole photographic
spectrum. The only reason of this must be particles of some reflecting
matter from which sunlight is reflected. The author refers this to
watery stuff, of which nine-tenths is left behind at the altitude at
which be worked. He then showed that the brightness of the ultra-violet
of direct sunlight increased enormously the higher the observer went,
but only to a certain point, for the spectrum suddenly terminated about
2,940 wave-length. This abrupt absorption was due to extra-atmospheric
causes and perhaps to space. The increase in brightness of the
ultra-violet was such that the usually invisible rays, L, M, N, could be
distinctly seen, showing that the visibility of these rays depended
on the intensity of the radiation. The red and ultra-red part of the
spectrum was also considered. He showed that the absorption lines were
present in undiminished force and number at this high altitude, thus
placing their origin to extra-atmospheric causes. The absorption from
atmospheric causes of radiant enemy in these parts he showed was due
to "water-stuff," which he hesitated to call aqueous vapor, since the
banded spectrum of water was present, and not lines. The B and A line he
also stated could not be claimed as telluric lines, much less as due to
aqueous vapor, but must originate between the sun and our atmosphere.
The author finally confirmed the presence of benzine and ethyl in the
same region. He had found their presence indicated in the spectrum at
sea-level, and found their absorption lines with undiminished intensity
at 8,500 feet. Thus, without much doubt, hydrocarbons must exist between
our atmosphere and the sun, and, it may be, in space.

Prof. Langley, following Capt. Abney, observed: The very remarkable
paper just read by Captain Abney has already brought information
upon some points which the one I am about, by the courtesy of the
Association, to present, leaves in doubt. It will be understood then
that the references here are to his published memoirs only, and not to
what we have just heard.

The solar spectrum is so commonly composed to have been mapped with
completeness, that the statement that much more than one-half its extent
is not only unmapped but nearly unknown, may excite surprise. This
statement is, however, I think, quite within the truth, as to that
almost unexplored region discovered by the elder Herschel, which, lying
below the red and invisible to the eye, is so compressed by the prism
that, though its aggregate heat effects have been studied through the
thermopile, it is only by the recent researches of Capt. Abney that we
have any certain knowledge of the lines of absorption there, even in
part. Though the last-named investigator has extended our knowledge of
it to a point much beyond the lowest visible ray, there yet remains a
still remoter region, more extensive than the whole visible spectrum,
the study of which has been entered on at Alleghany, by means of the
linear bolometer.

The whole spectrum, visible and invisible, is powerfully affected by the
selective absorption of our atmosphere and that of the sun; and we must
first observe that could we get outside our earth's atmospheric shell,
we should see a second and very different spectrum, and could we
afterward remove the solar atmosphere also, we should have yet a third,
different from either. The charts exhibited show:

1st. The distribution of the solar energy as we receive it, at the
earth's surface, throughout the entire invisible as well as visible
portion, both on the prismatic and normal scales. This is what I have
principally to speak of now, but this whole first research is but
incidental to others upon the spectra before any absorption, which
though incomplete, I wish to briefly allude to later. The other curves
then indicate:

2d. The distribution of energy before absorption by our own atmosphere.

3d. This distribution at the photosphere of the sun. The extent of
the field, newly studied, is shown by this drawing [chart exhibited].
Between H in the extreme violet, and A in the furthest red, lies the
visible spectrum, with which we are familiar, its length being about
4,000 of Angstrom's units. If, then, 4,000 represent the length of the
visible spectrum, the chart shows that the region below extends through
24,000 more, and so much of this as lies below wave-length 12,000, I
think, is now mapped for the first time.

[Illustration: FIG. 1.--PRISMATIC SPECTRUM.]

We have to pi = 12,000 relatively complete photographs, published by
Capt. Abney, but, except some very slight indications by Lamansky,
Desains, and Mouton, no further guide.

Deviations being proportionate to abscissae, and measured solar energies
to ordinates, we have here (1) the distribution of energy in the
prismatic, and (2) its distribution in the normal spectrum. The total
energy is in each case proportionate to the area of the curve (the two
very dissimilar curves inclosing the same area), and on each, if the
total energy be roughly divided into four parts, one of these will
correspond to the visible, and three to the invisible or ultra-red part.
The total energy at the ultra violet end is so small, then, as to be
here altogether negligible.

We observe that (owing to the distortion introduced by the prism) the
maximum ordinate representing the heat in the prismatic spectrum is, as
observed by Tyndall, below the red, while upon the normal scale this
maximum ordinate is found in the orange.

I would next ask your attention to the fact that in either spectrum,
below pi = 12,000 are most extraordinary depressions and interruptions
of the energy, to which, as will be seen, the visible spectrum offers
no parallel. As to the agent producing these great gaps, which so
strikingly interrupt the continuity of the curve, and, as you see,
in one place, cut it completely into two, I have as yet obtained no
conclusive evidence. Knowing the great absorption of water vapor in this
lowest region, as we already do, from the observations of Tyndall, it
would, _a priori_, seem not unreasonable to look to it as the cause. On
the other hand, when I have continued observations from noon to sunset,
making successive measures of each ordinate, as the sinking sun sent its
rays through greater depths of absorbing atmosphere, I have not found
these gaps increasing as much as they apparently should, if due to a
terrestrial cause, and so far as this evidence goes, they might be
rather thought to be solar. But my own means of investigation are not so
well adapted to decide this important point as those of photography, to
which we may yet be indebted for our final conclusion.

[Illustration: FIG. 2.--NORMAL SPECTRUM. (At sea level.)]

I am led, from a study of Capt. Abney's photographs of the region
between pi = 8,000 and pi = 12,000, to think that these gaps are
produced by the aggregation of finer lines, which can best be
discriminated by the camera, an instrument which, where it can be used
at all, is far more sensitive than the bolometer; while the latter, I
think, has on the other hand some advantage in affording direct and
trustworthy measures of the amount of energy inhering in each ray.

One reason why the extent of this great region has been so singularly
underestimated, is the deceptively small space into which it appears to
be compressed by the distortion of the prism. To discriminate between
these crowded rays, I have been driven to the invention of a special
instrument. The bolometer, which I have here, is an instrument depending
upon principles which I need not explain at length, since all present
may be presumed to be familiar with the success which has before
attended their application in another field in the hands of the
President of this Association.

I may remark, however, that this special construction has involved very
considerable difficulties and long labor. For the instrument here shown,
platinum has been rolled by Messrs. Tiffany, of New York, into sheets,
which, as determined by the kindness of Professor Rood, reach the
surprising tenuity of less than one twenty-five-thousandth of an English
inch (I have also iron rolled to one fifteen-thousandth inch), and from
this platinum a strip is cut one one-hundred-and-twenty-fifth of an inch
wide. This minute strip, forming one arm of a Wheatstone's bridge, and
thus perfectly shielded from air currents, is accurately centered by
means of a compound microscope in this truly turned cylinder, and the
cylinder itself is exactly directed by the arms of this Y.

The attached galvanometer responds readily to changes of temperature, of
much less than one-ten-thousandth degree F. Since it is one and the same
solar energy whose manifestations we call "light" or "heat," according
to the medium which interprets them, what is "light" to the eye is
"heat" to the bolometer, and what is seen as a dark line by the eye is
felt as a cold line by the sentient instrument. Accordingly, if lines
analogous to the dark "Fraunhofer lines" exist in this invisible region,
they will appear (if I may so speak) to the bolometer as cold bands, and
this hair-like strip of platina is moved along in the invisible part of
the spectrum till the galvanometer indicates the all but infinitesimal
change of temperature caused by its contact with such a "cold band." The
whole work, it will be seen, is necessarily very slow; it is in fact a
long groping in the dark, and it demands extreme patience. A portion of
its results are now before you.

The most tedious part of the whole process has been the determination of
the wave-lengths. It will be remembered that we have (except through the
work of Capt. Abney already cited, and perhaps of M. Mouton) no direct
knowledge of the wave-lengths in the infra-red prismatic spectrum, but
have hitherto inferred them from formulas like the well-known one of
Cauchy's, all which known to me appear to be here found erroneous by the
test of direct experiment, at least in the case of the prism actually
employed.

I have been greatly aided in this part of the work by the remarkable
concave gratings lately constructed by Prof. Rowland, of Baltimore, one
of which I have the pleasure of showing you. [Instrument exhibited.]

The spectra formed by this fall upon a screen in which is a fine slit,
only permitting nearly homogeneous rays to pass, and these, which may
contain the rays of as many as four overlapping spectra, are next passed
through a rock-salt or glass prism placed with its refracting edge
parallel to the grating lines. This sorts out the different narrow
spectral images, without danger of overlapping, and after their passage
through the prism we find them again, and fix their position by means of
the bolometer, which for this purpose is attached to a special kind of
spectrometer, where its platinum thread replaces the reticule of the
ordinary telescope. This is very difficult work, especially in the
lowermost spectrum, where I have spent over two weeks of consecutive
labor in fixing a single wave-length.

The final result is, I think, worth, the trouble, however, for, as you
see here, we are now able to fix with approximate precision and by
direct experiment, the wave-length of every prismatic spectral ray. The
terminal ray of the solar spectrum, whose presence has been certainly
felt by the bolometer, has a wave-length of about 28,000 (or is nearly
two octaves below the "great A" of Fraunhofer).

So far, it appears only that we have been measuring _heat_, but I
have called the curve that of solar "energy," because by a series of
independent investigations, not here given, the selective absorption
of the silver, the speculum-metal, the glass, and the lamp-black
(the latter used on the bolometer-strip), forming the agents of
investigation, has been separately allowed for. My study of lamp-black
absorption, I should add in qualification, is not quite complete. I have
found it quite transparent to certain infra-red rays, and it is very
possible that there may be some faint radiations yet to be discovered
even below those here indicated.

In view of the increased attention that is doubtless soon to be given
to this most interesting but strangely neglected region, and which by
photography and other methods is certain to be fully mapped hereafter, I
can but consider this present work less as a survey than as a sketch of
this great new field, and it is as such only that I here present it.

All that has preceded is subordinate to the main research, on which I
have occupied the past two years at Alleghany, in comparing the spectra
of the sun at high and low altitudes, but which I must here touch upon
briefly. By the generosity of a friend of the Alleghany Observatory, and
by the aid of Gen. Hazen, Chief Signal Officer of the U S. Army, I was
enabled last year to organize an expedition to Mount Whitney in South
California, where the most important of these latter observations were
repeated at an altitude of 13,000 feet. Upon my return I made a special
investigation upon the selective absorption of the sun's atmosphere,
with results which I can now only allude to.

By such observations, but by methods too elaborate for present
description, we can pass from the curve of energy actually observed to
that which would be seen if the observer were stationed wholly above the
earth's atmosphere, and freed from the effect of its absorption.

The salient and remarkable result is the growth of the blue end of the
spectrum, and I would remark that, while it has been long known from
the researches of Lockyer, Crova, and others that certain rays of short
wave-length were more absorbed than those of long, these charts show
_how much_ separate each ray of the spectrum has grown, and bring, what
seems to me, conclusive evidence of the shifting of the point of maximum
energy without the atmosphere toward the blue. Contrary to the accepted
belief, it appears here also that the absorption on the whole grows less
and less, to the extreme infra-red extremity; and on the other hand,
that the energy before absorption was so enormously greater in the blue
and violet, that the sun must have a decidedly bluish tint to the naked
eye, if we could rise above the earth's atmosphere to view it.

But even were we placed outside the earth's atmosphere, that surrounding
the sun itself would still remain, and exert absorption. By special
methods, not here detailed, we have at Alleghany compared the
absorption, at various depths, of the sun's own atmosphere for each
spectral ray, and are hence enabled to show, with approximate truth, I
think for the first time, the original distribution of energy throughout
the visible and invisible spectrum at the fount of that energy, in the
sun itself. There is a surprising similarity, you will notice, in the
character of the solar and telluric absorptions, and one which we could
hardly have anticipated _a priori_.

Here, too, violet has been absorbed enormously more than the green, and
the green than the red, and so on, the difference being so great, that
if we were to calculate the thickness of the solar atmosphere on the
hypothesis of a uniform transmission, we should obtain a very thick
atmosphere from the rate of absorption in the infra-red alone, and a
very thin one from that in the violet alone.

But the main result seems to be still this, that as we have seen in the
earth's atmosphere, so we see in the sun's, an enormous and progressive
increase of the energy toward the shorter wave-lengths. This conclusion,
which, I may be permitted to remark, I anticipated in a communication
published in the _Comptes Rendus_ of the Institute of France as long
since as 1875, is now fully confirmed, and I may mention that it is so
also by direct photometric methods, not here given.

If, then, we ask how the solar photosphere would appear to the eye,
could we see it without absorption, these figures appear to show
conclusively that it would be _blue_. Not to rely on any assumption,
however, we have, by various methods at Allegheny, reproduced this
color.

Thus (to indicate roughly the principle used), taking three Maxwell's
disks, a red, green, and blue, so as to reproduce white, we note the
three corresponding ordinates at the earth's surface spectrum, and,
comparing these with the same ordinates in the curve giving the energy
at the solar surface, we rearrange the disks, so as to give the
proportion of red, green, and blue which would be seen _there_, and
obtain by their revolution a tint which must approximately represent
that at the photosphere, and which is most similar to that of a blue
near Fraunhofer's "F."

The conclusion, then, is that, while all radiations emanate from the
solar surface, including red and infra-red, in greater degree than we
receive them, the blue end is so enormously greater in proportion that
the proper color of the sun, as seen at the photosphere is blue--not
only "bluish," but positively and distinctly blue; a statement which I
have not ventured to make from any conjecture, or on any less cause than
on the sole ground of long continued experiments, which, commenced some
seven years since, have within the past two years irresistibly tended to
the present conclusion.

The mass of observations on which it rests must be reserved for more
detailed publication elsewhere. At present, I can only thank the
association for the courtesy which has given me the much prized
opportunity of laying before them this indication of methods and
results.

       *       *       *       *       *




THE MINERALOGICAL LOCALITIES IN AND AROUND NEW YORK CITY, AND THE
MINERALS OCCURRING THEREIN.

[Footnote: Continued from SUPPLEMENTS 244 and 246.]

By NELSON H. DABTON.

PART III.


Hoboken.--The locality represented here is where the same serpentine
that we met on Staten Island crops out, and is known as Castle Hill. It
is a prominent object in view when on the Hudson River, lying on Castle
Point just above the Stevens Institute and about a mile north of the
ferry from Barclay or Christopher Street, New York city. Upon it is the
Stevens estate, etc., which is ordinarily inaccessible, but below this
and along the river walk, commencing at Fifth Street and to Twelfth,
there is an almost uninterrupted outcrop from two to thirty feet in
thickness and plentifully interspersed with the veins of the minerals
of the locality, which are very similar to those of Staten Island; the
serpentine, however, presenting quite a different appearance, being of a
denser and more homogeneous structure and color, and not so brittle or
light colored as that of Staten Island, but of a pure green color. The
veins of minerals are about a half an inch to--in the case of druses
of magnesite, which penetrate the rock in all proportions and
directions--even six inches in thickness. They lie generally in a
perpendicular position, but are frequently bent and contorted in every
direction. They are the more abundant where the rock is soft, as veins,
but included minerals are more plentiful in the harder rock. There is
hardly any one point on the outcrop that may be said to be favored in
abundance, but the veins of the brucites, dolomite, and magnesites are
scattered at regular and short intervals, except perhaps the last, which
is most plentiful at the north end of the walk.

_Magnesite_.--This mineral, of which we obtained some fine specimens on
Staten Island, occurs extremely plentifully here, constituting five or
six per cent. of a large proportion of the rock, and in every imaginable
condition, from a smooth, even, dark colored mass apparently devoid of
crystalline form, to druses of very small but beautiful crystals, which
are obtained by selecting a vein with an opening say from a quarter to a
half-inch between it and one or, if possible, both points of its contact
with the inclosing rock, and cutting away the massive magnesite and rock
around it, when fine druses and masses or geodes may be generally found
and carefully cut out. The crystals are generally less than a quarter of
an inch long, and the selection of a cabinet specimen should be based
more upon their form of aggregation that the size of the crystals.
Nearly all the veins hold more or less of these masses through their
total extent, but many have been removed, and consequently a careful
search over the veins for the above indications, of which there are
still plenty undeveloped or but partly so, would well repay an hour
or more of cutting into, by the specimens obtained. Patience is an
excellent and very necessary virtue in searching for pockets of
minerals, and is even more necessary here among the multitudinous barren
veins. One hint I might add, which is of final importance, and the
ignorance of which has so far preserved this old locality from
exhaustion, is that every specimen of this kind in the serpentine, of
any great uniqueness, is to be found within five feet from the upper or
surface end of the vein, which in this locality is inaccessible in the
more favored parts without a ladder or similar arrangement upon which
one may work to reach them. Here the veins will be found to be very far
disintegrated and cavernous, thus possessing the requisite conditions of
occurrence (this is also true of Staten Island, but there more or less
inaccessible) for this mineral and similar ones that occur in geodes or
drused incrustations, while it is just _vice versa_ for those occurring
in closely packed veins, as brucite, soapstone, asbestos, etc., where
they occur in finer specimens, where they are the more compact, which is
deep underground. This is also partly true of the zeolites and granular
limestone species with included minerals. I do not think there is any
rule, at least I have not observed it in an extended mineralogical
experience; but if they favor any part, it is undoubtedly the top, as
in the granular limestone and granite; however, they generally fall
subordinate to the first principle, as they more frequently, in this
formation, with the exception of chromic iron, occur not in the
serpentine but in the veins therein contained; for instance, crystals
of dolomite are found deeper in the rock as they occur in the denser
soapstone, which becomes so at a more or less considerable depth, with
spinel, zircon, etc., of the granular limestone. They occur generally in
pockets within five feat from the surface, but they can hardly be called
included minerals, as they are rather, as their mention suggests,
pockets, and adjacent or in contact with the intruded granite or
metamorphosed rock joining the formation at this point. This is
seemingly at variance when we consider datholite, but when we do find it
in pockets a hundred and fifty feet below the surface, in the Weehawken
tunnel, it is not in the trap, but on the surface of what was a cleft
or empty vein, since filled up with chlorite extending from the surface
down, while natrolite, etc., by the trap having clefts of such variable
and often great depth, allowed the solution of the portion thus
contributed that infiltered from the surface easy access to the beds
in which they lie, the mode of access being since filled with densely
packed calcite, which was present in over-abundance. This is not
applicable to serpentine, as the clefts are never of any great depth,
and the five feet before mentioned are a proportionately great depth
from the surface. As I mentioned in commencing this paper (Part I),
every part of the success of a trip lies in knowing where to find the
minerals sought; and by close observation of these relations much more
direction may be obtained than by my trying to describe the exact point
in a locality where I have obtained them or seen them. There is much
more satisfaction in finding rich pockets independently of direction,
and by close observance of indications rather than chance, or by having
them pointed out; for the one that reads this, and goes ahead of you to
the spot, and either destroys the remainder by promiscuous cuttings, or
carries them off in bulk, as there are many who go to a locality, and
what they cannot carry off they destroy, give you a disappointment in
finding nothing; consequently, I have considered that this digression
from our subject in detail was pardonable, that one may be independent
of the stated parts of the locality, and not too confidently rely on
them, as I am sometimes disappointed myself in localities and pockets
that I discover in spare time by finding that some one has been there
between times, and carried off the remainder. The characteristics of
magnesite I have detailed under that head under Pavilion Hill, Staten
Island; but it may be well to repeat them briefly here. Form as above
described, from a white to darker dirty color. Specific gravity, 2.8-3;
hardness, about 3.5. Before the blowpipe it is infusible, _and not
reduced to quicklime_, which distinguishes it from dolomite, which it
frequently resembles in the latter's massive form, common here in veins.
It dissolves in acid readily with but little effervescence, which
little, however, distinguishes it from brucite, which it sometimes
resembles and which has a much lower-specific gravity when pure.

_Dolomite_.--This mineral has been very common in this locality.
It differs, perhaps, as I have before explained, from magnesite in
containing lime besides magnesia, and from calc spar by the _vice
versa_. Much of the magnesite in this serpentine contains more or less
lime, and is consequently in places almost pure dolomite, although
crystals are seldom to be found in this outcrop, it all occurring as
veins about a half-inch thick and resembling somewhat the gurhofite
of Staten Island, only that it is softer and less homogeneous in
appearance. Its color is slightly tinged green, and specimens of it are
not peculiarly unique, but perhaps worth removing. Its characteristics
are: first, its burning to quicklime before the blowpipe, distinguishing
it from pure magnesite; second, its slow effervescence in acids. Besides
these, its specific gravity is 2.8, hardness, 8.5; from calcspar it
cannot be distinguished except by chemical analysis, as the two species
blend almost completely with every intermediate stage of composition
into either calc spar, or, what occurs in this locality, aragonite,
similar in composition to it, or dolomite. The color of the last,
however, is generally darker, and it cleaves less readily into its
crystalline form, which is similar to calc spar, and of which it is
harder, 3.5 to 3 of calc spar.

_Aragonite_.--This mineral, identical in composition with calc spar, but
whose crystalline form is entirely different, occurs in this locality in
veins hardly recognizable from the magnesite or dolomite, and running
into dolomite. It is not abundant, and the veins are limited in extent;
the only distinguishment it has from the dolomite, practically, is its
fibrous structure, the fibers being brittle and very coarse. If examined
with a powerful glass, they will be seen to be made up of modified long
prisms. The specific gravity is over 2.9, hardness about 4, unless much
weathered, when it becomes apparently less. There are some small veins
at the north end of the walk, and in them excellent forms may be found
by cutting into the veins.

_Brucite_.--This mineral occurs here in fair abundance, it being one of
the principal localities for it in the United States, and where formerly
extremely unique specimens were to be obtained. It has been pretty well
exhausted, however, and the fine specimens are only to be obtained by
digging into the veins of it in the rock, which are quite abundant on
the south end of the walk, and, as I before noted, as deep as possible
from the top of the veins, as it is a closely packed mineral not
occurring in geodes, druses, etc. Two forms of it occur; the one,
nemalite, is in fibers of a white to brown color resembling asbestos,
but the fibers are brittle, and hardly as fine as a typical asbestos. It
is packed in masses resembling the brucite, from which it only differs
in breaking into fibers instead of plates, as I have explained in my
description of that species (see Part II). They are both readily soluble
in acids, with effervescence, and infusible but crumble to powder before
the blowpipe, or at least become brittle; when rubbed in mass with a
piece of iron, they phosphoresce with a yellow light; specific gravity,
2.4, hardness, 1.5 to 2. Its ready solubility in acids without
effervescence at once distinguishes it from any mineral that it may
resemble. The specimens of nemalite may be more readily obtained than
the brucite but fine specimens of both may be obtained after finding a
vein of it, by cutting away the rock, which is not hard to do, as it
is in layers and masses packed together, and which maybe wedged out in
large masses at a time with the cold chisel and hammer, perhaps at the
rate of three or four cubic feet an hour for the first hour, and in
rapidly decreasing rate as progress is made toward the unweathered rock
and untouched brucite, etc.

_Serpentine_.--Fair specimens of this may be obtained of a dark oil
green color, but not translucent or peculiarly perfect forms. The
variety known as marmolite, which splits into thin leaves, is plentiful
and often well worth removing.

_Chromic Iron_.--Crystals of this are included in the denser rock
in great abundance; they are very small, seldom over a few lines
in diameter, of an iron black color, of a regular octahedral form;
sometimes large crystals may be found in place or in the disintegrated
loose rock. I have seen them a half inch in diameter, and a half dozen
in a small mass, thus forming an excellent cabinet specimen. By finding
out by observation where they are the thickest in the rock, and cutting
in at this point, more or less fine crystals may be obtained. This is
readily found where they are so very abundant, near the equidistant
points of the walk, that no difficulty should be encountered in so
doing. These characteristics are interesting, and if large specimens
cannot be obtained, any quantity of the small crystals may be split out,
and, as a group, used for a representative at least. Before the blowpipe
it is infusible, but if powdered, it slowly dissolves in the molten
borax bead and yields a beautiful green globule. The specific gravity,
which is generally unattainable, is about 4.5, and hardness 5 to 6. Its
powder or small fragments are attracted by the magnet. A few small veins
of this mineral are also to be found horizontally in the rock, and
small masses may be obtained. They are very rare, however. I have seen
numerous agates from this locality, but have not found them there
myself. They may be looked for in the loose earth over the outcrop, or
along the wall of the river. Our next locality is Paterson, N. J., or
rather in a trip first to West Paterson by the D.L. & W. Railroad,
Boonton branch, then back to Paterson proper, which is but a short
distance, and then home by the Erie road, or, if an excursion ticket has
been bought, on the D.L. & W, back from West Paterson. Garret Rock holds
the minerals of Paterson, and although they are few in number, are very
unique. The first is phrenite. This beautiful mineral occurs in
geodes, or veins of them, near the surface of the basalt, which is the
characteristic formation here, and lies on the red sandstone.

These veins are but two or three feet from the surface, and the ones
from which the fine specimens are to be and have been obtained are
exposed by the railroad cutting about a thousand feet north of the
station at West Paterson, and on the west side of the rails. Near or
below the beds is a small pile of debris, prominent by being the only
one in the vicinity near the rails. In this loose rock and the veins
which are by this description readily found and identified, they are
about three inches in thickness, and in some places widen out into
pockets even a foot in diameter They look like seams of a dark earth,
with blotches of white or green matter where they are weathered, but are
fresher in appearance inside. The rock, in the immediate vicinity of the
veins, is soft, and may be readily broken out with the hammer of, if
possible, a pick bar, and thus some of these geode cavities broken into,
and much finer specimens obtained than in the vein proper. Considerable
occurs scattered about in the before-mentioned pile of loose rock and
debris, and if one does not prize it sufficiently to cut into the rock,
taking the chances of lucky find, plenty may be obtained thus; but as
it has been pretty thoroughly picked over where loose, it is much more
satisfactory to obtain the fine specimens in place in the rock. When
the bed for the railroad was being cut here, many fine specimens were
obtained by those in the vicinity, and the natives of the place have it
in abundance, and it may be obtained from many of them for a trifle, if
one is not inclined to work it out. The mineral itself occurs in masses
in the vein of a white, greenish white, or more or less dark green
color. Sometimes yellowish crystals of it occur plentifully in short
thick prisms, but the common form is that of round coralloid bunches,
having a radiated structure within. Sometimes it is in masses made up
of a structure resembling the leaves of a book slightly opened, and in
nearly every shape and size. Crystals of the various forms may be well
secured, and also the different colors from the deep green to the blue
white, always remembering that true, perfect crystals are of more value
than masses or attempted forms. The specific gravity is 2.8 to
2.9, hardness nearly 7 before the blowpipe; it readily fuses after
intumescing; it dissolves in hot acid without gelatinizing, leaving a
flaky residue.

_Datholite_.--This mineral is very abundant as inferior specimens, and
frequently very fine ones may be obtained. They occur all around Garret
Rock at the juncture of the basalt and red sandstone, in pockets, and as
heavy druses. They are most abundant near the rock cuttings between West
Paterson and Paterson, and may be cut out by patient labor. This is a
long known and somewhat noted locality for datholite, and no difficulty
need be experienced in obtaining plenty of fair specimens. Near them is
the red sandstone, lying under the basalt, and baked to a scoriaceous
cinder. Upon this is a layer of datholite in the form of a crystalline
plate, and over or above this, either in the basalt or hanging down into
cavities in the sandstone, are the crystals or geodes of datholite. Old
spots are generally exhausted, and consequently every new comer has to
hunt up new pockets, but as this is readily done, I will not expend
further comment on the matter. The datholite, as in other localities,
consists of groups of small colorless crystals. Hardness, about 5;
specific gravity, 3. Before the blowpipe it intumesces and melts to a
glassy globule coloring the flame green, and forms a jelly when boiled
with the acids.

_Pectolite_--This mineral is also quite abundant in places, the greater
part occurring with or near the phrenite before mentioned, in small
masses generally more or less weathered, but in very fair specimens,
which are about an inch in thickness. It is readily recognized by its
peculiar appearance, which, I may again repeat, is in fibrous masses,
these fibers being set together in radiated forms, and are quite tough
and flexible, of a white color, and readily fused to a globule before
the blowpipe.

_Feldspar_.--This mineral occurs strewn over the hill from place to
place, and is peculiarly characterized by its lively flesh red color,
quite different from the dull yellowish gray of that from Staten Island
or Bergen Hill. Fine crystals of it are rather rare, but beautiful
specimens of broken groups may be obtained in loose debris around the
hill and in its center. I have not been able to locate the vein or veins
from which it has come, but persistent search will probably reveal it,
or it may be stumbled upon by accident. Some of the residents of the
vicinity have some fine specimens, and it is possible that they can
direct to a plentiful locality. However, some specimens are well worth
a thorough search, and possess considerable value as mineralogieal
specimens. The specific gravity of the mineral is 2.6, and it has a
hardness of 6 before the blowpipe. It is with difficulty fused to a
globule, more or less transparent. It occurs undoubtedly in veins in the
basalt and near the surface of the outcrop As this locality has never
before been mentioned as affording this species, it is fresh to the
amateur and other mineralogists, and there need be no difficulty in
obtaining some fine specimens. Its brilliant color distinguishes it from
other minerals of the locality.

It is possible that some of the other zeolites as mentioned under Bergen
Hill occur here, but I have not been able to find them. The reason
may be that the rock is but little cut into, and consequently no new
unaltered veins are exposed.

COPPER MINES, ARLINGTON, N. J.--A short distance north of this station,
on the New York and Greenwood Lake Railroad, and about nine miles from
Jersey City, is one of the cuttings into the deposits of copper which
permeate many portions of the red sandstone of this and the allied
districts in Connecticut and Massachusetts, and which have been so
extensively worked further south at Somerville and New Brunswick, etc.
There are quite a variety of copper minerals occurring in these mines,
and as they differ but little in anything but abundance, I will describe
this, the one nearest to New York City, as I promised in commencing
these papers. The locality of this mine may be readily found, as it is
near the old turnpike from Jersey City, along which the water-pipes or
aqueduct, are laid. By taking the road directly opposite to the station
at Arlington, walking north to its end, which is a short distance, then
turning to the left along the road, there crossing and turning north up
the next road joining this, until the turnpike is reached; this is then
followed east for about a quarter-mile, passing occasional heaps in the
road of green earth, until the head of a descent is reached, when we
turn off into the field to the left, and there find the mine near the
heaps of greenish rocks and ore scattered about, a distance from the
station of about a mile and a half through a pleasing country. The
entrance to the mine is to the right of the bank of white earth on the
edge of, and in the east side of the hill; it is a tunnel more or less
caved in, running in under the heaps of rock for some distance. It will
not be necessary, even if it were safe, to venture into the mine, but
all the specimens mentioned below may be obtained from the heaps of ore
and rock outside, and in the outcrops in the east side of the hill, a
little north of the mouth of the tunnel to the mine. The hammer and cold
chisel will be necessary, and about three hours should be allowed to
stay, taking the noon train from New York there, and the 5.09 P.M. train
in return, or the 6.30 A.M. train from the city, and the 1.57 P.M. in
return. This will give ample opportunity for the selection of specimens,
and, if time is left, to visit the water works, etc.

_Green Malachite_.--This is the prominent mineral of the locality, and
is conspicuous by its rich green color on all the rocks and in the
outcrops. Fine specimens of it form excellent cabinet specimens. It
should be in masses of good size, with a silky, divergent, fibrous
structure, quite hard, and of a pure oil green color, for this purpose.
Drused crystals of it are also very beautiful and abundant, but very
minute. As the greater part of it is but a sixteenth or eighth of an
inch in thickness, it may require some searching to secure large masses
a quarter to a half-inch in thickness, but there was considerable, both
in the rock, debris, and outcrop, remaining the last visit I made to the
place a few months ago. The mineral is so characterized by its color and
solubility in acid that a detailed description of it is unnecessary to
serve to distinguish it. Its specific gravity is 4, and hardness about
4. It decrepitates before the blowpipe, but when fused with some borax
in a small hollow on a piece of wood charcoal, gives a globule of
copper. It readily dissolves in acids, with effervescence, as it is a
carbonate of copper.

_Red Oxide of Copper_--This rather rare mineral is found in small
quantities in this mine, or near it, in the debris or outcrop. Perfect
crystals, which are of a dodecahedral or octahedral form, are fairly
abundant. They are difficult to distinguish, as they are generally
coated, or soiled at least, with malachite. The color proper is of
a brownish red, and the hardness about 4, although sometimes, it is
earthy, with an apparent hardness not over 2. The crystals are generally
about a quarter of an inch to a half of an inch in diameter, and found
inside the masses of malachite. When these are broken open, the red
copper oxide is readily distinguished, and may be separated or brought
into relief by carefully trimming away the malachite surrounding it as
its gravity (6) is much greater than malachite. When a piece of the last
is found which has a high gravity, it may be suspected and broken into,
as this species is much more valuable and rarer than the malachite
which is so abundant. It dissolves in acids like malachite, but without
effervescence, if it be freed from that mineral, and acts the same
before the blowpipe. Sometimes it may be found as an earthy substance,
but is difficult to distinguish from the red sandstone accompanyit,
which both varieties resemble, but which, not being soluble in the
acids, find having the blowpipe reactions, is thus characterized. This
red oxide of copper does not form a particularly showy cabinet specimen,
but its rarity and value fully compensate for a search after it. I have
found considerable of it here, and seen some little of it in place
remaining.

_Chrysorolla_.--This mineral, very abundant in this locality, resembles
malachite, but has a much bluer, lighter color, without the fibrous
structure so often present in malachite, and seldom in masses, it only
occurring as light druses and incrustations, some of which are very
beautiful, and make very fine cabinet specimens. Its hardness is less
than that of the other species, being under 3, and a specific gravity
of only 2, but as it frequently occurs mixed with them, is difficult to
distinguish. It does not dissolve in nitric acid, although that takes
the characteristic green color of a solution of nitrate of copper,
as from malachite or red oxide. This species is found all over this
locality, and a fine drused mass of it will form an excellent memento of
the trip.

_Copper Glance_.--This mineral is quite abundant in places here, but
fine crystals, even small, as it all is, are rare. That which I have
seen has been embedded in the loose rock above the mine, about a quarter
inch in diameter, and more or less disguised by a green coating of
chrysocolla. The color of the mineral itself is a glistening grayish
lead color, resembling chromite somewhat in appearance, but the crystals
of an entirely different shape, being highly modified or indistinct
rhombic prisms. The specific gravity is over 5, and the hardness 4.
Before the blowpipe on a piece of wood charcoal it gives off fumes of
sulphur, fuses, boils, and finally leaves a globule of copper. In nitric
acid it dissolves, but the sulphur in combination with it separates as
a white powder. A steel knife blade placed in this solution receives a
coating of copper known by its red color.

_Erubescite_--This mineral occurs massive in the rock here with the
other copper minerals, and is of a yellowish red color, more or less
tarnished to a light brown on its surface, Before the blowpipe on
charcoal it fuses, burns, and affords a globule of copper and iron,
which is attracted by the magnet. Its specific gravity is 5, hardness
3. It resembles somewhat the red oxide, but the low gravity, inferior
hardness, lighter color, and blowpipe reaction distinguish it. These
are the only copper minerals likely to be found at this mine, and the
following table and note will show their characteristics:

Name.    Speci-   Hardness  Action of       Action of   Color.     Form.
         fic                Blowpipe Heat.  Hot Nitric
         Gravity.                           Acid.

Mala-    From 4   From 3    Decrepitates,   Dissolves   Pure Oil   Fibrous,
chite    to 4.5   to 4      but fuses with  with        Green.     massive,
                            borax to a      effer-                 or in-
                            green bead.     vescence               crusting.

Red      6        From 3.5  On charcoal     Dissolves   A deep     Modified
Oxide             to 4      yields a        without     brownish   crystals.
                            globule of      effer-      red.
                            copper.         vescence

Chryso-  From 2   From 2    Infusible.      Partly      Bright     Incrus-
colla    to 2.3   to 3                      soluble     bluish     tations.
                                                        green.

Copper   5        From 2.5  Fumes of        Copper      Grayish    Modified
Glance            to 3      sulphur and a   soluble,    Lead.      rhombic
                            globule of      sulphur                prisms.
                            copper          deposits

Erube-   5        From 3    Fumes of        Partly      Yellowish  Massive.
scite             to 3.5    sulphur and     soluble     red or
                            magnetic                    tarnished.
                            globule.

Malachite is characterized by its color from Copper Glance and Red Oxide
and Erubescite, and from Chrysocolla by the action of the acid, the
fibrous structure and blowpipe reaction, gravity, and hardness.

Red Oxide is distinguished from Erubescite, which it alone resembles,
by its darker color, higher specific gravity, and yielding a globule of
pure copper.

Chrysocolla is characterized by its low specific gravity, light color,
lack of fibrous structure, blowpipe reactions, and the acid.

Copper Glance is distinguished by its color, fumes of sulphur, and
globule of copper.

Erubescite is distinguished from Red Oxide, which it alone resembles, by
its lighter color, great solubility when pure, and yielding a magnetic
globule before the blowpipe in the hollow of a piece of wood charcoal,
which is used instead of platinum wire in this investigation.

       *       *       *       *       *




ENTOMOLOGY.

[Footnote: From the _American Naturalist_, November, 1882.]


THE BUCKEYE LEAF STEM BORER.--In our account of the proceedings of the
entomological sub-section of the A.A.A.S., at the 1881 meeting (see
_American Naturalist_, 1881, p. 1009), we gave a short abstract of Mr.
E.W. Claypole's paper on the above insect, accepting the determination
of the species as _Sericoris instrutana_, and mentioning the fact that
the work of _Proteoteras æsculana_ Riley upon maple and buckeye was very
similar. A letter recently received from Mr. Claypole, prior to sending
his article to press, and some specimens which be had kindly submitted
to us, permit of some corrections and definite statements. We have a
single specimen in our collection, bred from a larva found feeding, in
1873, on the blossoms of buckeye, and identical with Mr. Claypole's
specimens, which are in too poor condition for description or positive
determination. With this material and with Mr Claypole's observations
and our own notes, the following facts are established:

1st. We have _Proteoteras æsculana_ boring in the terminal green twigs
of both maple and buckeye, in Missouri, and often producing a swelling
or pseudo-gall. Exceptionally it works in the leaf-stalk. It also feeds
on the samara of maple, as we reared the moth in June, 1881, from
larvæ infesting these winged seeds that had been collected by Mr. A.J.
Wethersby, of Cincinnati, O.

2d. We have an allied species, boring in the leaf-stalk of buckeye,
in Ohio, as observed by Mr. Claypole. It bears some resemblance
to _Proteoteras æsculana_, but differs from it in the following
particulars, so far as can be ascertained from the poor material
examined: The primaries are shorter and more acuminate at apex.
Their general color is paler, with the dark markings less distinctly
separated. No distinct tufts of scales or knobs appear, and the
ocellated region is traversed by four or five dark longitudinal lines.
It would be difficult to distinguish it from a rubbed and faded specimen
of _æsculana_, were it not for the form of the wing, on which, however,
one dare not count too confidently. It probably belongs to the same
genus, and we would propose for it the name of _claypoleana_. The
larva is distinguished from that of _æsculana_ by having the minute
granulations of the skin smooth, whereas in the latter each granule has
a minute sharp point.

3d. _Sericoris instrutana_ is a totally different insect. Hence our
previous remarks as to the diversity of food-habit in this species have
no force--_C.V.R._

       *       *       *       *       *

DEFOLIATION OF OAK TREES BY DRYOCAMPA SENATORIA IN PERRY COUNTY,
PA.--During the present autumn the woods and road-sides in this
neighborhood (New Bloomfield) present a singular appearance in
consequence of the ravages of the black and yellow larva of the above
species. It is more abundant, so I am informed, than it has ever been
before. In some places hardly any trees of the two species to which its
attack is here limited have escaped. These are the black or yellow oak
(_Q. tinctoria_) with its variety (_coccinea_), the scarlet oak and, the
scrub oak (_Q. ilicifolia_). These trees appear brown on the hill-sides
from a distance, in consequence of being altogether stripped of
their leaves. The sound of the falling frass from the thousands of
caterpillars resembles a shower of rain. They crawl in thousands over
the ground, ten or twelve being sometimes seen on a square yard. The
springs and pools are crowded with drowned specimens. They are equally
abundant in all parts of the county which I have visited during the
past week or two--the central and southeastern.--_E. W. Olaypole, New
Bloomfield, Pa_.

       *       *       *       *       *

EFFICACY OF CHALCID EGG-PARASITES.--Egg-parasites are among the most
efficient destroyers of insects injurious to vegetation, since they kill
their victim before it has begun to do any damage; but few persons are
aware of the vast numbers in which these tiny parasites occasionally
appear. Owing to the abundance of one of them (_Trichogramma pretiosa_
Riley), we have known the last brood of the cotton-worm to be
annihilated, and Mr. H.G. Hubbard reported the same experience at
Centerville, Fla. Miss Mary E. Murtfeldt has recently communicated to us
a similar experience with a species of the Proctotrupid genus Telenomus,
infesting the eggs of the notorious squash-bug (_Coreus tristis_). She
writes: "The eggs of the Coreus have been very abundant on our squash
and melon vines, but fully ninety per cent. of them thus far [August 2]
have been parasitized--the only thing that has saved the plants from
utter destruction."

       *       *       *       *       *

ON THE BIOLOGY OF GONATOPUS PILOSUS Thoms--Professor Josef Mik, in the
September number of the _Wiener Entomologische Zeitung_ (pp. 215-221,
pl. iii), gives a most interesting account of the life history of the
curious Proctotrupid, _Gonatopus pilosus_ Thoms., which has not before
been thoroughly understood. Ferris, in his "Nouvelles excursions dans
les grandes Landes," tells how, from cocoons of parasitic larvae on
_Athysanus maritima_ (a Cicadellid) he bred _Gonatopus pedestris_, but
this he considered a secondary parasite, from the fact that it issued
from an inner cocoon. It appears from the observations of Mik, however,
that it was in all probability a primary parasite, as with the species
studied by the latter (_G. pilosus_) the larva spins both an outer
and an inner cocoon. The larva of _Gonatopus pilosus_ is an external
parasite upon the Cicadellid _Deltocephalus xanthoneurus_ Fieb. The eggs
are laid in June or July, and the larvae, attaching themselves at the
junction of two abdominal segments, feed upon the juices of their host.
But one parasite is found upon a single Cicadellid, and it occasionally
shifts its position from one part of the abdomen to another. Leaving its
host in September, it spins a delicate double cocoon in which it remains
all winter in the larva state, transforming to pupa in May, and issuing
as an imago in June.

It will be remembered that the female in the genus Gonatopus is
furnished with a very remarkable modification of the claws of the front
tarsi, which are very strongly developed, and differ somewhat in shape
in the different species. It has usually been supposed that these claws
were for the purpose of grasping prey, but Professor Mik offers the more
satisfactory explanation that they are for the purpose of grasping the
Cicadellids, and holding them during the act of oviposition.

It is interesting to note that there is in the collection of the
Department of Agriculture a specimen of _Amphiscepa bivittata_ Say,
which bears, in the position described above, a parasitic larva similar
to that described by Mik. It left its victim and spun a white cocoon,
but we failed to rear the imago. It is probably the larva of a
Gonatopus, and possibly that of the only described American species of
the genus, _Gonatopus contortulus_ Patton (_Can. Ent._, xi p. 64).

       *       *       *       *       *

SPECIES OF OTIORHYNCHIDAE INJURIOUS TO CULTIVATED PLANTS--Of our
numerous species of this family, we know the development and earlier
stages of only one species, viz, Fuller's rosebeetle (_Aramigus
Fulleri_[1]). A few other species have attracted attention by the injury
caused by them as perfect insects. They are as follows: _Epicoerus
imbricatus_, a very general feeder; _Pachnoeus opalus_ and _Artipus
floridanus_, both injurious to the orange tree. Of a few other species
we know the food-plants: thus _Neoptochus adspersus_ feeds on oak;
_Pachnoeus distans_ on oak and pine; _Brachystylus acutus_ is only
found on persimmon; _Aphrastus toeniatus_ lives on pawpaw (but not
exclusively); _Eudiagogus pulcher_ and _rosenschoeldi_ defoliate the
coffee-weeds (_Cassia occidentalis_ and other species of the same
genus). Two very common species, _Pandeleteius hilaris_ and _Tanymecus
confertus_, appear to be polyphagous, without preference for any
particular plant. Very recently the habits of another species, _Anametis
grisea_ Horn, were brought to our knowledge by Mr. George P. Peffer, of
Pewaukee, Wis., who sent us specimens of the beetle accompanied by the
following communication: "The larger curculio I send you is working
around the roots of apple and pear trees, near the surface of the ground
or around the union where grafts are set. I found fifteen of the larvae
on a small tree one and a half inches in diameter. The beetle seems to
lay its eggs just where the bark commences to be soft, near or partly
under the ground. The larvae eat the bark only, but they are so numerous
as to girdle the tree entirely in a short time."--_C. V. Riley_.

[Footnote 1: Vide Annual Report Department of Agriculture, 1878, p.
257.]

BOMBYLIID LARVAE DESTROYING LOCUST EGGS IN ASIA MINOR.--The eggs of
locusts in Cyprus and the Dardanelles, as we learn from the Proceedings
of the London Entomological Society, are much infested with the
parasitic larvae of _Bombyltidae_, though these were previously not
known to occur on the island. This fact shows that the habit which we
discovered among some of our N. A. _Bombyliids_ recurs in other parts
of the world, and we have little doubt that careful search among locust
eggs will also reveal the larval habits of some of the _Meloïdae_ in
Europe and elsewhere. Indeed, notwithstanding the closest experiments
of Jules Lichtenstein, which show that the larva of the Spanish
blister-beetle of commerce will feed on honey, we imagine that its more
natural food will be found in future to be locust eggs. The particular
_Bombyliid_ observed by Mr. Frank Calvert destroying locusts in the
Dardanelles is _Callostoma fascipennis_ Macq., and its larva and pupa
very closely resemble those of _Triodites mus_. which we have studied
and figured (see Vol. XV., pl. vi.). We quote some of Mr. Calvert's
observations:

"On the 24th of April I examined the larvae in the ground; the only
change was a semi-transparent appearance which allowed of a movable
black spot to be seen in the body. On the 8th June about fifty per cent.
of the larvae had cast a skin and assumed the pupal state in their
little cells: the color yellowish-brown, darkening to gray in the more
advanced insect. About one per cent. of the cells, in which were two
skins and an aperture to the surface, showed the perfect insect to have
already come out of them. A gray pupa I was holding in my hand suddenly
burst its envelope, and in halt a minute on its legs stood a fly, thus
identifying the perfect insect.... I found the fly, now identified,
sucking the nectar of flowers, especially of the pink scabious and
thistle, plants common in the Troad. (Later on I counted as many as
sixteen flies on a thistle-head.) The number of flies rapidly increased
daily until the 13th, when the ground appeared pitted all over with
small holes from whence the parasite had issued. A few pupae were then
still to be found--a larva the rare exception. The pupal state thus
seems to be of short duration. It was very interesting to watch the
flies appearing above ground; first the head was pushed out; then, with
repeated efforts, the body followed; the whole operation was over in
two or three minutes; the wings were expanded, but the colors did not
brighten until some time after. Occasionally a pupa could not cast
off its envelope, and came wriggling out of the ground, when it was
immediately captured by ants. Unfortunate flies that could not detach
the covering membrane adhering to the abdomen, also fell a prey, as
indeed many of the flies that could not get on their legs in time. The
flies for the first time 13th June, were seen to pair, but this rarely."

       *       *       *       *       *




SPARROWS IN THE UNITED STATES.--EFFECT OF ACCLIMATION, ETC.


The house sparrows were first brought to New York city in 1862. They
might have been introduced in consideration of the scientific usefulness
of the experiment; but the importation was made solely in view of the
benefit to result from their immense consumption of larvae.

I have long observed peculiarities in their acclimation which are hardly
known at all, and which must have a scientific importance. The subject
might also be worthy of general interest, so numerous and familiar have
the sparrows become all over our country.

Walking on Fifth avenue, or in the parks of the city, during the
breeding season, one's attention is repeatedly attracted by the pitiful
shrill call of a sparrow fallen on the pavement upon its first attempt
at flight, or by the stronger note of a mother sparrow, sharply
bewailing the fate of a little one, killed by the fall, or dispatched
alive by the cat.

Should we take and examine these little weaklings, we should find
generally that they are at a period when they normally should have the
strength for flight, and we should also find that they are almost always
of a lightish tint, some with head white, others with streaks and spots
of white on the tail or back, and occasionally one is found entirely
white, with red eyes--a complete albino. It is an accepted fact that the
city-sparrow is everywhere of a lighter color than that of the country.
But here the greater lightness exists in so many cases, to such
a degree, and particularly in female sparrows, that it should be
discussed, at least in part, under the head of albinism.

That so many which lack the muscular strength in their wings should be
so generally affected with albinism, is a significant fact to those
interested in this phenomenon.

Many hold, with Darwin, that this extraordinary want of coloring matter,
occasionally met with in all animals, is not to be regarded as an index
denoting an unhealthful condition of the animal. That it is so often
united in the young sparrow with physical inability, argues favorably
for those who bold a different view.

In my observations, what has struck me as a most curious fact, and what
I have found to be generally ignored, is that this wide-spread albinism
and general weakness of our acclimated house-sparrow are not found among
its progenitors.

Throughout several sojourns that I made in Europe. I searched for a
token of the remarkable characteristics existing here, but I never
succeeded in finding one in England, France, or in Germany, nor have I
met an observer that has.

This albinism and weakness, existing simultaneously to such an extent in
our young house-sparrows, are evidently the result of their acclimation.

The hypothesis that our now _numerous_ sparrows, being descended from
a _few_ European birds, and that, probably, continual and close
reproduction among individuals of the same stock, as in the case of our
original _few_ sparrows, has encouraged weakness in the race, can hardly
serve as an explanation of this phenomenon, because the sparrow is so
prolific that, after a few years, so many families had been formed that
the relation between them became very distant.

The reason for the greater proportion of albinism found in the young is
obvious; the young sparrows affected with albinism, lacking usually the
physical strength to battle their way in life, meet death prematurely,
and thus a very small proportion of the number is permitted to reach
maturity, while those that do owe it to some favoring circumstance. Many
are picked up and cared for by the public; and among those to whom these
sparrows generally owe such prolongation of life are the policemen in
our public parks, who often bring these little waifs to their homes,
keeping some, and sending others out into the world, after caring for
them until they have acquired the sufficient strength. However, almost
all of these albino-sparrows are picked up by the cat, and immediately
disposed of to the feline's physical benefit. They form such a prominent
diet among the cats near Washington Park, where I live, that, upon the
removal of some of our neighbors to the upper part of the city, it was
noticed that their cat became dissatisfied and lean, as sparrow-meat is
not to be found so extensively there, but it finally became resigned,
finding it possible to procure about three sparrows daily.

And here attention should be called to the method employed by our cats
to catch not only the weak, but fine, healthy sparrows as well; it ought
perhaps to be looked upon as a mark of intellectual improvement, for
originally their attempts consisted chiefly in a very unsuccessful
giving chase to the flying bird, whereas the cats of to-day are skilled
in a hundred adroit devices. It has often been a source of enjoyment to
watch their well-laid schemes and delicate maneuverings.

What wonder then, with such dainty fare at his disposal, that the cat is
often found to have become indifferent to rats, and even to mice?

There are several notable changes, no more desirable than the foregoing,
which have been caused by the introduction of the house-sparrow. The
only positive benefit which occurs to me is that the measuring worm,
which formerly infested all our vegetation, is now very nearly extinct
through the instrumentality of the sparrows. A pair of these, during the
breeding-season, destroys four thousand larvae weekly.

In some places, complaints are made that their untidy nests mar the
appearance of trees and walls.

The amount of havoc in our wheatfields created yearly by them is
enormous. Their forwardness and activity have driven all other birds
from where they have settled, so that the hairy caterpillars, which
sparrows do not eat and which used to be extensively consumed by other
birds, are now greatly on the increase, probably the only creatures, at
present, enjoying the domestication of the sparrow in this country....
I have also to remark that the sparrows here betray much less pugnacity
than in Europe.--E.M., M.D.

       *       *       *       *       *

It is stated in the _Chemical Review_ that recent analyses of the water
from the _Holy Well_ at Mecca, which is so eagerly drunk by pilgrims,
show this water to be sewage, about ten times stronger than average
London sewage.

       *       *       *       *       *




HOW TO ESTABLISH A TRUE MERIDIAN.


In looking over the excellent article of Professor S. M. Haupt, in the
SCIENTIFIC AMERICAN SUPPLEMENT, No. 360, on the subject of finding the
meridian, I discovered that one important step is not given, which,
might prove an embarrassment to a new beginner.

In the fourth paragraph, in the third column of page 5,748, he says:
"Having now found the altitude, correct it for refraction, ... and the
result will be the latitude."

It will be observed that this result is only the true altitude of the
star. The _latitude_ is found by further increasing or diminishing this
altitude by the polar distance of the star.

This paper will be of great value to engineers and surveyors, for the
elementary works on surveying have not treated the subject clearly.

H. C. PEARSONS, C.E.

Ferrysburg, Mich.

       *       *       *       *       *

A catalogue, containing brief notices of many important scientific
papers heretofore published in the SUPPLEMENT, may be had gratis at this
office.

       *       *       *       *       *




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