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SCIENTIFIC AMERICAN SUPPLEMENT NO. 530




NEW YORK, FEBRUARY 27, 1886

Scientific American Supplement. Vol. XXI, No. 530.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.

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TABLE OF CONTENTS.

I.    CHEMISTRY ETC.--Decomposition and Fermentation of Milk.


II.   ENGINEERING AND MECHANICS.--The Ethics of Engineering
      Practice.--An address by Mr. JAS. C. BAYLES, before the American
      Institute of Mining Engineers.

      Lifting a 40-inch Water Main.--With engraving.

      The Inter-oceanic Canal Question.

      The Mersey Tunnel.

      Improved Revolver.--With 4 figures.

      Motors for Street Railways.--Results of experiments on mechanical
      motors for tramways made by the jury on railway appliances
      at the Antwerp Exhibition.--By Capt. DOUGLAS GALTON.


III.  TECHNOLOGY.--Alizarine Dyes.--Process of dyeing.--Recipes for
      various colors.

      Cement Paving.--Composition made by the Wilkes' Metallic
      Flooring Company.--Other compositions.

      A New Bleaching Process.--The "Mather-Thompson" system.

      Instruments for Drawing Curves.--By Prof. C.W. MACCORD--1.
      The Hyperbola--2 figures.

      Experiments with Fibers.--By Dr. THOS. TAYLOR.--Detection of
      Fraud.--Method employed.--Cotton mixed with linen.--Experiments
      with flax.--Wool tested with acid.--Tests of dyed black silk.

      Orthochromatic Plates.--By CH. SCOLIK.

      A New Photographic Apparatus.--With engraving.


IV.   ELECTRICITY, PHYSICS, ETC.--On the Theory of the
      Electro-magnetic Telephone Transmitter.--By E. MERCADIER.

      On the Theory of the Receiver of the Electro-magnetic
      Telephone.--By E. MERCADIER.

      Frew's Improved Pyrometer.--With engraving.

      Dew.--Abstract of a paper read before the Royal Society of
      Edinburgh.--By Mr. AITKEN.--Source of dew.--Observations of the
      temperature of the ground.--Experiments.--Effects of
      wind.--Excretion of drops of liquid by plants.--Radiating power of
      different surfaces at night.


V.    ASTRONOMY.--Meteorites.--The Dhurmsala Meteorite.

      Telescopic Search for the Trans-Neptunian Planet.--By DAVID P.
      TODD.


VI.   ARCHITECTURE.--The New "Burgtheater" in Vienna.--With
      full page engraving.

      The New German Bookdealers' Exchange in Leipzig.--With engraving.


VII.  MISCELLANEOUS.--Notes on Manual Spelling.--By JAS. C.
      GORDON.--Origin of Finger Spelling.--Finger alphabets.--With
      engraving of American alphabet.

      Fruits and Seeds for Dress Trimming.--Origin of the use of
      Fruits and Seeds.--Preparation by MR. COLLIN.


VIII. BIOGRAPHY.--Hon. Hiram Sibley.--The founder of the Sibley
      College of Mechanic Arts of Cornell University.--With portrait.

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HON. HIRAM SIBLEY.


Hon. Hiram Sibley, of the city of Rochester, a man of national reputation
as the originator of great enterprises, and as the most extensive farmer
and seedsman in this country, was born at North Adams, Berkshire County,
Mass., February 6, 1807, and is the second son of Benjamin and Zilpha
Davis Sibley. Benjamin was the son of Timothy Sibley, of Sutton, Mass.,
who was the father of fifteen children--twelve sons and three daughters;
eight of these, including Benjamin, lived to the aggregate age of 677
years, an average of about seventy-five years and three months. From the
most unpromising beginnings, without education, Hiram Sibley has risen to
a postion of usefulness and influence. His youth was passed among his
native hills. He was a mechanical genius by nature. Banter with a
neighboring shoemaker led to his attempt to make a shoe on the spot, and
he was at once placed on the shoemaker's bench.

At the age of sixteen he migrated to the Genesee Valley, where he was
employed in a machine shop, and subsequently in wool carding. Before he
was of age he had mastered five different trades. Three of these years
were passed in Livingston County. His first occupation on his own account
was as a shoemaker at North Adams; then he did business successfully as a
machinist and wool carder in Livingston County, N.Y.; after which he
established himself at Mendon, fourteen miles south of Rochester, a
manufacturing village, now known as Sibleyville, where he had a foundry
and machine shop. When in the wool carding business at Sparta and Mount
Morris, in Livingston County, he worked in the same shop, located near
the line of the two towns, where Millard Filmore had been employed and
learned his trade; beginning just after a farewell ball was given to Mr.
Filmore by his fellow workmen.

Increase of reputation and influence brought Mr. Sibley opportunities for
office. He was elected by the Democrats Sheriff of Monroe County in 1843
when he removed to Rochester; but his political career was short, for a
more important matter was occupying his mind. From the moment of the
first success of Professor Morse with his experiments in telegraphy, Mr.
Sibley had been quick to discern the vast promise of the invention; and
in 1840 he went to Washington to assist Professor Morse and Ezra Cornell
in procuring an appropriation of $40,000 from Congress to build a line
from Washington to Baltimore, the first put up in America. Strong
prejudices had to be overcome. On Mr. Sibley's meeting the chairman of
the committee having the matter in charge, and expressing the hope that
the application would be granted, he received for answer: "We had made up
our minds to allow the appropriation, when the Professor came in and
upset everything. Why! he undertook to tell us that he could send ten
words from Washington to Baltimore in two minutes. Good heavens! Twenty
minutes is quick enough, but two minutes is nonsense. The Professor is
too radical and visionary, and I doubt if the committee recommend the sum
to be risked in such a manner." Mr. Sibley's sound arguments and
persuasiveness prevailed, though he took care not to say what he
believed, that the Professor was right as to the two minutes. Their joint
efforts secured the subsidy of $40,000.

This example stimulated other inventors, and in a few years several
patents were in use, and various lines had been constructed by different
companies. The business was so divided as to be always unprofitable. Mr.
Sibley conceived the plan of uniting all the patents and companies in one
organization. After three years of almost unceasing toil, he succeeded in
buying up the stock of the different corporations, some of it at a price
as low as two cents on the dollar, and in consolidating the lines which
then extended over portions of thirteen States. The Western Union
Telegraph Company was then organized, with Mr. Sibley as the first
president. Under his management for sixteen years, the number of
telegraph offices was increased from 132 to over 4,000, and the value of
the property from $220,000 to $48,000,000.

In the project of uniting the Atlantic and Pacific by a line to
California, he stood nearly alone. At a meeting of the prominent
telegraph men of New York, a committee was appointed to report upon his
proposed plan, whose verdict was that it would be next to impossible to
build the line; that, if built, the Indians would destroy it; and that it
would not pay, even if built, and not destroyed. His reply was
characteristic; that it should be built, if he had to build it alone. He
went to Washington, procured the necessary legislation, and was the sole
contractor with the Government. The Western Union Telegraph Company
afterward assumed the contract, and built the line, under Mr. Sibley's
administration as president, ten years in advance of the railroad.

[Illustration: HIRAM SIBLEY.]

Not satisfied with this success at home, he sought to unite the two
hemispheres by way of Alaska and Siberia, under P. McD. Collins'
franchise. On visiting Russia with Mr. Collins in the winter of 1864-5,
he was cordially received and entertained by the Czar, who approved the
plan. A most favorable impression had preceded him. For when the Russian
squadron visited New York in 1863--the year after Russia and Great
Britain had declined the overture of the French government for joint
mediation in the American conflict--Mr. Sibley and other prominent
gentlemen were untiring in efforts to entertain the Russian admiral,
Lusoffski, in a becoming mariner. Mr. Sibley was among the foremost in
the arrangements of the committee of reception. So marked were his
personal kindnesses that when the admiral returned he mentioned Mr.
Sibley by name to the Emperor Alexander, and thus unexpectedly prepared
the way for the friendship of that generous monarch. During Mr. Sibley's
stay in St. Petersburg, he was honored in a manner only accorded to those
who enjoy the special favor of royalty. Just before his arrival the Czar
had returned from the burial of his son at Nice; and, in accordance with
a long honored custom when the head of the empire goes abroad and
returns, he held the ceremony of "counting the emperor's jewels;" which
means an invitation to those whom his majesty desires to compliment as
his friends, without regard to court etiquette or the formalities of
official rank. At this grand reception in the palace at Tsarskozela,
seventeen miles from St. Petersburg, Mr. Sibley was the second on the
list, the French ambassador being the first, and Prince Gortchakoff, the
Prime Minister, the third. This order was observed also in the procession
of 250 court carriages with outriders, Mr. Sibley's carriage being the
second in the line. On this occasion Prince Gortchakoff turning to Mr.
Sibley, said: "Sir, if I remember rightly, in the course of a very
pleasant conversation had with you a few days since, at the State
department, you expressed your surprise at the pomp and circumstance
attending upon all court ceremony. Now, sir, when you take precedence of
the Prime Minister, I trust you are more reconciled to the usage
attendant upon royalty, which was so repugnant to your democratic ideas."
Such an honor was greatly appreciated by Mr. Sibley; for it meant the
most sincere respect of the "Autocrat of all the Russias" for the people
of the United States, and a recognition of the courtesies conferred upon
his fleet when in American waters.

Mr. Sibley was duly complimented by the members of the royal family and
others present, including the ambassadors of the great powers. Mr.
Collins, his colleague in the telegraph enterprise, shared in these
attentions. Mr. Sibley was recorded in the official blue book of the
State department of St. Petersburg as "the distinguished American," by
which title he was generally known. Of this book he has a copy as a
souvenir of his Russian experience. His intercourse with the Russian
authorities was also facilitated by a very complimentary letter from
Secretary Seward to Prince Gortchakoff. The Russian government agreed to
build the line from Irkootsk to the mouth of the Amoor River. After 1,500
miles of wire had been put up, the final success of the Atlantic cable
caused the abandonment of the line, at a loss of $3,000,000. This was a
loss in the midst of success, for Mr. Sibley had demonstrated the
feasibility of putting a telegraphic girdle round the earth. In railway
enterprises the accomplishments of his energy and management have been no
less signal than in the establishment of the telegraph. One of these was
the important line of the Southern Michigan and Northern Indiana Railway.
His principal efforts in this direction have been in the Southern States.
After the war, prompted more by the desire of restoring amicable
relations than by the prospect of gain, he made large and varied
investments at the South, and did much to promote renewed business
activity. At Saginaw. Mich., he became a large lumber and salt
manufacturer. He bought much property in Michigan, and at one time owned
vast tracts in the Lake Superior region, where the most valuable mines
have since been worked. While he has been interested in bank and
manufacturing stocks, his larger investments have been in land. Much of
his pleasure has been in reclaiming waste territory and unproductive
investments, which have been abandoned by others as hopeless. The
satisfying aim of his ambition incites him to difficult undertakings,
that add to the wealth and happiness of the community, from which others
have shrunk, or in which others have made shipwreck. Besides his
stupendous achievements in telegraph and railway extension, he is
unrivaled as a farmer and seed grower, and he has placed the stamp of his
genius on these occupations, in which many have been content to work in
the well-worn ruts of their predecessors.

The seed business was commenced in Rochester thirty years ago. Later, Mr.
Sibley undertook to supply seeds of his own importation and raising and
others' growth, under a personal knowledge of their vitality and
comparative value. He instituted many experiments for the improvements of
plants, with reference to their seed-bearing qualities, and has built up
a business as unique in its character as it is unprecedented in amount.
He cultivates the largest farm in the State, occupying Howland Island, of
3,500 acres, in Cayuga County, near the Erie Canal and the New York
Central Railroad, which is largely devoted to seed culture; a portion is
used for cereals, and 500 head of cattle are kept. On the Fox Ridge farm,
through which the New York Central Railroad passes, where many seeds and
bulbs are grown, he has reclaimed a swamp of six hundred acres, making of
great value what was worthless in other hands, a kind of operation which
affords him much delight. His ownership embraces fourteen other farms in
this State, and also large estates in Michigan and Illinois.

The seed business is conducted under the firm name of Hiram Sibley & Co.,
at Rochester and Chicago, where huge structures afford accommodations for
the storage and handling of seeds on the most extensive scale. An
efficient means for the improvement of the seeds is their cultivation in
different climates. In addition to widely separated seed farms in this
country, the firm has growing under its directions several thousands of
acres in Canada, England, France, Germany, Holland, and Italy.
Experimental grounds and greenhouses are attached to the Rochester and
Chicago establishments, where a sample of every parcel of seed is tested,
and experiments conducted with new varieties. One department of the
business is for the sale of horticultural and agricultural implements of
all kinds. A new department supplies ornamental grasses, immortelles, and
similar plants used by florists for decorating and for funeral emblems.
Plants for these purposes are imported from Germany, France, the Cape of
Good Hope, and other countries, and dyed and colored by the best artists
here. As an illustration of their methods of business, it may be
mentioned that the firm has distributed gratuitously, the past year,
$5,000 in seeds and prizes for essays on gardening in the Southern
States, designed to foster the interests of horticulture in that section.

The largest farm owned by Mr. Sibley, and the largest cultivated farm in
the world, deserves a special description. This is the "Sullivant Farm,"
as formerly designated, but now known as the "Burr Oaks Farm," originally
40,000 acres, situated about 100 miles south of Chicago, on both sides of
the Wabash, St. Louis, and Pacific Railroad. The property passed into the
hands of an assignee, and, on Mr. Sullivant's death in 1879, came into
the possession of Mr. Sibley. His first step was to change the whole plan
of cultivation. Convinced that so large a territory could not be worked
profitably by hired labor, he divided it into small tracts, until there
are now many hundreds of such farms; 146 of these are occupied by tenants
working on shares, consisting of about equal proportions of Americans,
Germans, Swedes, and Frenchmen. A house and a barn have been erected on
each tract, and implements and agricultural machines provided. At the
center, on the railway, is a four-story warehouse, having a storage
capacity of 20,000 bushels, used as a depot for the seeds grown on the
farm, from which they are shipped as wanted to the establishments in
Chicago and Rochester. The largest elevator on the line of the railway
has been built, at a cost of over $20,000; its capacity is 50,000
bushels, and it has a mill capable of shelling and loading twenty-five
cars of corn a day. Near by is a flax mill, also run by steam, for
converting flax straw into stock for bagging and upholstery. Another
engine is used for grinding feed. Within four years there has sprung up
on the property a village containing one hundred buildings, called Sibley
by the people, which is supplied with schools, churches, a newspaper,
telegraph office, and the largest hotel on the route between Chicago and
St. Louis. A fine station house is to be erected by the railway company.

Mr. Sibley is the president and largest stockholder of the Bank of
Monroe, at Rochester, and is connected with various institutions. He has
not acquired wealth simply to hoard it. The Sibley College of Mechanic
Arts of Cornell University, at Ithaca, which he founded, and endowed at a
cost of $100,000, has afforded a practical education to many hundreds of
students. Sibley Hall, costing more than $100,000, is his contribution
for a public library, and for the use of the University of Rochester for
its library and cabinets; it is a magnificent fire-proof structure of
brownstone trimmed with white, and enriched with appropriate statuary.
Mrs. Sibley has also made large donations to the hospitals and other
charitable institutions in Rochester and elsewhere. She erected, at a
cost of $25,000, St. John's Episcopal Church, in North Adams, Mass., her
native village. Mr. Sibley has one son and one daughter living--Hiram W.
Sibley, who married the only child of Fletcher Harper, Jr., and resides
in New York, and Emily Sibley Averell, who resides in Rochester. He has
lost two children--Louise Sibley Atkinson and Giles B. Sibley.

A quotation from Mr. Sibley's address to the students of Sibley College,
during a recent visit to Ithaca, is illustrative of his practical thought
and expression, and a fitting close to this brief sketch of his practical
life: "There are two most valuable possessions which no search warrant
can get at, which no execution can take away, and which no reverse of
fortune can destroy; they are what a man puts into his head--_knowledge_;
and in to his hands--_skill_."--_Encyclopædia of Contemporary Biography_.

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HYDRASTIS IN DYSPEPSIA.--Several correspondents in _The Lancet_ have
lauded hydrastis as a most useful drug in dyspepsia.

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THE ETHICS OF ENGINEERING PRACTICE.


At the Pittsburg meeting of the American Institute of Mining Engineers,
held from the 16th to the 19th of February, Mr. James C. Bayles, the
President, delivered the following address:

GENTLEMEN OF THE INSTITUTE: Having availed myself somewhat liberally
during the past two years of the latitude which is accorded the president
in the selection of the topics presented in addresses from the chair, I
do not need to plead safe precedent as my warrant for devoting the
address which marks the conclusion of my service in the dignified and
honorable office to which, through your unmerited favor, I have been
twice chosen, to the consideration of some of the questions in casuistry
the answers to which will be found to furnish a basis for a code of
professional ethics. It is not asking too much of the engineer that his
professional morality shall conform to higher standards than those which
govern men who buy and sell with no other object than the getting of
gain. The professional man stands in a more confidential relation to his
client than is supposed to exist between buyer and seller in trade. He is
necessarily more trusted, and has larger opportunities of betraying the
confidence reposed in him than is offered the merchant or the business
agent. For the reason that he cannot be held to the same strict
accountability which law and usage establish in mercantile business, he
is under a moral obligation to fix his own rules of conduct by high
standards and conform to them under all circumstances. Whatever the
measure of his professional success--whether wealth and reputation crown
his career, or disappointment and poverty be his constant and unwelcome
companions--no taint of suspicion should attach to any professional act
or utterance. Not only should we be able to write above the wreck of
bright hopes, "Honor alone remains," but upon our great and successful
achievements should it be possible for others to inscribe the legend, "In
honor wrought; with honor crowned."

It is frequently and confidently asserted that at no time in the history
of the world were the standards of business honor so high as now. The
prevalence of dishonesty, in one form or another, is held to show that
there is a great deal of moral weakness which is unequal to the strain to
which principle is subjected in the keenness of business competition, and
in the presence of the almost unlimited confidence which apparently
characterizes commercial intercourse. The enormous volume of the daily
transactions on 'change, where a verbal agreement or a sign made and
recognized in the midst of indescribable confusion has all the binding
force of a formal contract; the real-estate and merchandise transactions
effected on unwitnessed and unrecorded understandings; the certification
of checks on the promise of deposits or collaterals, and a hundred other
evidences of confidence, are cited as proof that the accepted standards
of business honor are high, and are kept so by public opinion. All of
this is true, in a certain limited sense; but the confidence which is the
basis of all business creates opportunities for dishonesty which changes
its shape with more than Protean facility when detected and denounced.
The keenness of competition in all departments of professional and
business enterprise presents a constant temptation to seize every
advantage, fair or unfair, which promises immediate profit. It is
unfortunately true that the successful cleverness which sacrifices honor
to gain is more easily condoned by public opinion than honest dullness
which is caught in the snares laid for it by the cunning manipulators of
speculation. The man who fails to deliver what he has bought, to meet his
paper at maturity and make good the certifications of his banker, loses
at once his business standing, and is practically excluded from business
competition; but if he keeps his engagements and is successful, the
public is kindly blind to the agencies he may employ to depreciate what
he wants to buy or impart a fictitious value to what he wants to sell.
Viewed from this standpoint, it may be questioned whether the accepted
standards of business morality are not, after all, those fixed by the
revised statutes.

In so far as the engineer is brought in contact with the activities of
trade, he cannot fail to be conscious of the fact that serious
temptations surround him. Such reputation as he has gained is assumed to
have a market value, and the price is held out to him on every side. It
should not be difficult for the conscientious engineer, jealous of his
professional honor, to decide what is right and what is not. He does not
need to be reminded that he cannot sell his independence nor make
merchandise of his good name. But as delicate problems in casuistry may
mislead or confuse him, it is to be regretted that so little effort has
been made to formulate a code of professional ethics which would help to
right decisions those who cannot reach them unaided.

Standing in the presence of so many of those who have dignified the
profession of engineering, I should hesitate to express my views on this
subject did I not believe that many earnest and right-minded young men in
our active and associate membership will be glad to know what rules of
conduct govern those whose example they would willingly follow, and how
one not a practicing engineer, but with good opportunities of observation
and judgment, would characterize practices which have been to some extent
sanctioned by custom. To those who have yet to win the gilded spurs of
professional knighthood, but who cherish a high and honorable ambition,
my suggestions are chiefly addressed.

An ever present stumbling block in the path of the young engineer is what
is lightly spoken of as the "customary commission"--a percentage paid him
on the price of machinery and supplies purchased or recommended by him.
That manufacturers expect to pay commissions to engineers who are
instrumental in effecting the sale of their products is a striking proof
that the standards of business morality are quite as low as I have
assumed them to be; that engineers do not unite in indignant protest
against the custom, and denounce as bribe-givers and bribe-takers those
who thus exchange services, shows that the iron has entered the souls of
many who may be disposed to resent such plain terms as those in which I
decree it my duty to describe transactions of this kind.

The young man who is tendered a commission will naturally ask himself
whether he can accept and retain it, and may, perhaps, reason somewhat in
this way: "My professional advice was given without expectation of
personal profit other than that earned in my fee, and it expressed my
best judgment. The price at which the goods were purchased was that which
every consumer must pay, and was not increased for my advantage. The
transaction was satisfactory to buyer and seller, and was concluded when
payment was made. I am now tendered a commission which I am at liberty to
accept or to decline. If I decline it, I lose something, my client gains
nothing, and the remaining profit to the seller is greater than he
expected by that amount. If I accept it, I do my client no wrong. If it
is the custom of manufacturers to pay commissions, it must be the custom
of engineers to receive them; and there is no reason why I should be
supersensitive on a point long since decided by usage." This is false
reasoning, based upon erroneous assumptions. Why do manufacturers pay
commissions? Is it probable they make it a part of their business policy
to give something for nothing? Is it not certain that they expect an
equivalent for every dollar thus disbursed, and that in paying the
engineer a commission they are seeking to establish relations with him
which shall warp his judgment and make him their agent? It may be urged
in the case of reputable manufacturers that they yield to this custom
because other manufacturers have established it, and that in following
the pernicious example they have no other object than to equalize the
influences tending to the formation of professional judgment. This
reasoning does not change in the least the moral aspects of the question
from the manufacturer's standpoint, but what engineer with a delicate
sense of professional honor could offer or hear such an explanation
without feeling the hot blush of shame suffuse his cheeks? The plain
truth about the commission is that the manufacturer or dealer adds it to
the selling price of his goods, and the buyer unconsciously pays the
bribe designed to corrupt his own agent. Can an engineer receive and
retain for his own use a commission thus collected from his client
without a surrender of his independence, and having surrendered that, can
he conscientiously serve the client who seeks disinterested advice and
assistance in the planning and construction of work?

It is possible, perhaps, for a man to dissociate his preferences from his
interests; so, also, is it possible for one to walk through fire and not
scorch his garments but how few are able to do it! The young man in
professional life who begins by accepting commissions will soon find
himself expecting and demanding them, and from that moment his
professional judgment is as much for sale as pork in the shambles. I
counsel the young man thus tempted to ask himself, Am I entitled to pay
from the manufacturer who offers it? If so, for what? If not, will my
self-respect permit me to become his debtor for a gratuity to which I
have no claim? Does not this money belong to my client, as an overcharge
unconsciously paid by him for my benefit? If I refuse it, can I not with
propriety demand in future that the percentage which this commission
represents shall be deducted in advance from the manufacturer's price,
that my client may have the benefit of it? If this is denied, can I
resist the conclusion that it is a bribe to command future services at my
hands? Is not the smile of incredulity with which the dealer receives my
assurance that I can only take it for my client and hand it over to him,
an insult to the profession, which, as a man of honor, I am bound to
resent?

Gentlemen, it is not true that custom sanctions the acceptance of
commissions by the engineer. That it is much too general I will not deny,
but there are very few men of recognized professional standing who would
confess that they have yielded to the temptation and retained for their
own benefit the commissions received by them. I do not hesitate to give
it as my opinion that the acceptance and retention of a commission is
incompatible with a standard of professional honor to which every
self-respecting engineer should seek to conform. Those who defend it as
proper and right, and plead the sanction of usage, are not the ones to
whom the young engineer can safely go for counsel and advice. The most
dangerous and least reputable of all the competition he will encounter in
an attempt to make an honest living in the practice of his profession is
that of the engineer who charges little for professional services and
expects to be paid by those whose goods are purchased on his
recommendation.

With equal emphasis would I characterize as unprofessional the framing of
specifications calling for patented or controlled specialties when, to
deceive the client, bids are invited. I am well aware that it is easier
to procure drawings and specifications from manufacturers than to make
them. Many manufacturers are very willing to furnish them, but those who
do are careful to so frame the specifications that they can secure the
contracts at prices to include the cost of the professional work for
which the engineer is also paid. There is nothing unprofessional in
recommending a patented article or process if it be, in the judgment of
the engineer, the best for the purpose to be accomplished, but he will do
it openly and with the courage of his convictions. The young engineer
should, I think, have no difficulty in recognizing the important
difference which inheres in the methods by which a given result is
accomplished.

In the relations of engineers to contractors there is many a snare and
pitfall for the unwary feet of the beginner. In superintending the
construction of work the engineer may err on the side of unreasonable
strictness or on that of improper leniency. If so disposed, he can
involve any contractor in loss and do him great wrong, but it more often
happens that the engineer is forced to assume a defensive attitude and to
resist influences too strong for a man of average courage and strength of
will, especially if his experience in charge of work is limited. He
should enter upon the discharge of his delicate and responsible duties
with a desire to do impartial justice between client and contractor. He
is warranted in assuming that his judgment and discretion are his chief
qualifications for the position of supervising engineer, and that all
specifications are designed to be in some measure elastic, since the
conditions to be encountered in carrying them out cannot possibly be
known in advance. He should not impose unnecessary and unreasonable
requirements upon the contractor, even if empowered to do so by the
letter of the specifications. The danger, however, is principally in the
opposite direction. Frequently the engineer has all he can do to hold the
contractor to a faithful performance of the spirit of his agreement. He
is bullied, misled, deceived, and sometimes openly defied. He must
constantly defend himself against charges impeaching his personal
integrity and his professional intelligence. The contractor can usually
succeed in making it appear that he is the victim of persecution, and
especially in public work he is likely to have more influence than the
engineer with those for whom the work is done. It often happens that the
engineer, defeated and discouraged, gives up the unequal battle. From
that moment he is of no further use as an engineer, and if he remains for
an hour in responsible charge of work he cannot control, he rates his fee
as more desirable than a reputation unsullied by the stain of dishonor.
He has a right to decline a conflict for which he feels unequal, but he
has no right to consent to a sacrifice of the interests of his client
while he is paid to protect them. The questions of professional ethics
arising out of the relations between the engineer and the contractor are
much too complex to be decided by an inflexible rule of professional
conduct, but the engineer cannot make a mistake in refusing to remain in
responsible charge of work when, by remaining, he must give consent to
that which his judgment tells him involves a wrong to his client. With
equal confidence may it be asserted that the engineer who secretly
participates in the profits of the contractor, whatever the arrangement
by which such participation is brought about, sacrifices his professional
standing.

In making reports for contingent fees or fees of contingent value, the
young engineer needs to exercise great discretion. This may be done
without impropriety if done openly; but it is safe to assume that few
opportunities will come to the young man with a reputation still to make
in which he can do clean and creditable work on any such basis. The
engineer called upon to make a report for a fee in stock which depends
for its value upon the effect of his report in creating confidence in the
public mind, takes a fearful risk. However honest he may be, he places
himself in a position in which the danger is obvious and the advantage
uncertain. If, having a contingent interest in the result of his work, he
is afraid to say so in his report, he may safely consider his position
unprofessional and unsafe. Contingent fees are a delusion and a snare,
and in making it a rule to refuse them the young engineer will be likely
to gain more than he loses.

Reports intended to influence the public upon subjects concerning which
the engineer knows himself unqualified to speak with authority are to be
classed with other forms of charlatanry. No man can claim infallibility
of judgment, nor is this expected of the engineer, whatever his position;
but those who pay for professional services have a right to demand that
the man who assumes to speak as an expert shall have the special
knowledge which will command for his opinion the respect of those who are
well informed. I consider it unprofessional for the engineer to enter
upon the discharge of any duties for which he knows he is not qualified,
if for the satisfactory discharge of those duties he must assume a
knowledge he does not possess. There has been an immense amount of
unprofessional work done in the field of reporting, and many reputations
have been blasted by a failure to draw nice distinctions in questions of
professional honor. The young engineer cannot be too careful in this
matter, and he will be fortunate if, with all the prudence he can
exercise, he is able to avoid disaster. Of a professional reputation
dependent upon the accuracy as well as the honesty of reports ordered and
used for speculative purposes, one may say as a marine underwriter lately
said of an unseaworthy steamer, that he "would not insure her against
sinking, from Castle Garden to Sandy Hook, with a cargo of shavings."

In the matter of expert service in the courts I am disposed to speak
guardedly. I see no reason why an engineer should not willingly go upon
the witness stand to give expert testimony if he has made proper
preparation and has an honest conviction that his testimony can be given
with a conscientious regard for the obligations of his oath as a witness.
It is his duty and his privilege to defend his opinions, for the man
without opinions which he is prepared to defend is worthless as a witness
and cannot properly be called an expert. But the conscientious engineer
has no right to appear as a partisan of anything except what he believes
to be the truth. If he finds himself parrying the questions of the
cross-examination with a view to concealing the truth, if he realizes
that he is a partisan of the side which retains him, and feels a
temptation to earn his fee by falsehood, concealment, or evasion, he can
be sure that he is in a position in which no man of honor has a right to
be. The abuses of expert testimony in civil and criminal suits are many
and grave; its uses are perhaps exaggerated, and the witness stand is not
an inviting field for the young engineer seeking a satisfactory career.

How far an engineer can properly use for his own advantage information
gained in the discharge of duties of a confidential nature, is a question
at once delicate and difficult. He cannot help knowing what he has
learned, and his knowledge is his capital. He must be governed in this
matter by the considerations which influence men of honor in the ordinary
relations of life. Stock and real estate operations, on confidential
information which belongs to one's principals, are usually in violation
of the simplest rules of professional honor. The manager who advises his
brokers by telegraph and his principals by mail cannot, I think, claim to
have a very delicate sense of right and wrong. He can judge his own
conduct by the standard he would apply in judging like infidelity on the
part of those employed by him.

In professional criticism of professional work, it is easy to fall into
ways which are wrong, morally and professionally. Criticism which is
designed merely to advertise the critic serves no good purpose, and
savors of charlatanry or something worse. Only a small proportion of the
current critical literature of engineering serves any good or useful
purpose, since it has no other or higher object than to help the critics
to climb into notoriety on the shoulders of the older and wiser men with
whom they are brought into competition. I regard as unprofessional every
effort to discredit honest and intelligent work, and every form of
disguised advertising designed to give an engineer a greater prominence
than he has earned by successful and creditable work, or is entitled to
claim by virtue of fitness for more than average professional
achievements.

It is neither possible nor desirable to catalogue the unprofessional
practices which in one way or another come to the notice of those
observant of current happenings in the several departments of
engineering. It is the contention of some that right and wrong are
relative terms, applying to no action or line of conduct save as it is
considered in relation to coincident and contingent circumstances. I will
not deny that this may be true of all professional acts, but the
impossibility of an arbitrary classification under the heads right and
wrong, honorable and dishonorable, need not make it difficult for a man
to formulate a code of professional ethics by which his own conduct shall
be governed. There are certain broad ethical principles which never
change. One is that a man cannot serve two masters having conflicting
interests, and be faithful to each. Another is that, however skillfully
one may juggle words to conceal meanings or evade responsibility, if the
intent to deceive is there, he lies. Professional ethics are no different
from the ethics of the Decalogue; they are specific applications of the
rules of conduct which have governed enlightened and honorable men in all
ages and in all walks of life. It is only when the moral sense is blunted
or temptation presents itself in some new and unrecognized form that it
is difficult to draw the line between right and wrong. I am aware that a
delicate sense of honor often comes between a man and his opportunities
of profit, and that a fine sensitiveness is rarely appreciated at its
value by those who employ professional service. I know that in this busy
world men of affairs do not always stop to weigh motives, and that
confident assurance always commands respect, while modest merit is
distrusted. But I do not know that a man can sell his honor for a price,
and retain thereafter the right to stand erect in the presence of his
fellows. I do not know that any engineer can make for himself a
creditable and satisfactory career of whom it cannot be said that,
whatever his mistakes or successes, his failures or triumphs, he has held
his professional honor above suspicion.

       *       *       *       *       *




LIFTING A FORTY INCH WATER MAIN.


[Illustration: RAISING A FORTY INCH MAIN ON THE BOSTON WATER WORKS.]

The sketch below, reproduced from a photograph, shows the general method
adopted for lifting a 40 inch water main on Brookline Avenue, in Boston,
Mass. _Engineering News_ says:

The work, which was commenced in June, 1884, included the raising of
1,000 feet of this main from to 18 feet to adjust it to a new grade in
the avenue. The plan pursued by the Boston Water Department was about as
follows:

After the pipe was uncovered, piles were driven in pairs on each side, 5
feet 6 inches apart, and in bents 12 feet apart; the pile-heads were then
tenoned, and a cap made of two pieces of 4 by 12 in. stuff was bolted on
as shown, and the bents stayed longitudinally. The lifting was done with
the pipe empty, by screws 8 feet long, working in square nuts resting on
a broad iron plate on the cap pieces. After all preparatory work was
completed, the lifting of the pipe to its new position was accomplished
in about nine hours.

After the pipe was raised, two more 4 by 12 inch pieces were bolted to
the piles just under the pipe, and the bottoms of the piles were
cross-braced. Stringers made of two 6 by 12 inch timbers were then placed
on the caps, and a track of standard gauge put into place, upon which the
dump cars used in filling the avenue were run out.

The engineer in charge was Mr. Dexter Brackett, and we understand from
him that a 48 inch main is to be raised in a somewhat similar manner
during the present year.

       *       *       *       *       *




THE INTEROCEANIC CANAL QUESTION.


Mr. J. Foster Crowell lately read a paper before the Engineers' Club of
Philadelphia upon the Present Situation of the Inter-oceanic Canal
Question, presenting the subject from a general standpoint. He sketched
the history of the various past attempts to establish communication
through the American Isthmus, and traced the developments in the
different directions of effort, which finally concentrated the problem
upon the three projects now before the world, summarizing the progress in
each case, and stating the following propositions:

I. That Panama is the only possible site for a Sea Level Canal, and that
such treatment is the only feasible method at that place.

II. That Nicaragua is the only practicable site for a Slack Water system
(for a canal with locks), and that it is pre-eminently adapted by nature
for such a use; that there are no obstacles in an engineering sense, and
no physical drawbacks that need deter the undertaking.

III. That the Ship Railway, as a mechanical contrivance, has the
indorsement of the best authorities, and may be admitted to be the _ne
plus ultra_ as a means of taking ships from their natural element and
transporting them over the land.

IV. That none of these plans has as yet advanced sufficiently to warrant
our considering its completion as beyond doubt.

V. That, as the _additional_ sum now asked for by De Lesseps (_even if
sufficient_) to complete the Panama Canal is _greater_ than the estimated
cost of either Nicaragua Canal or the Ship Railway, it would be
economical to abandon the Panama Canal, and the money sunk in it, to
date, unless its location and form possess paramount advantages; and we
therefore may profitably consider the relative merits of the three lines
without regard to the past, from four standpoints, viz.:

1. Geographical convenience of location.

2. Adaptiveness to all marine requirements, present and future.

3. Political security.

4. Economy of construction and operation.

He then discussed the comparative claims to excellence. In the first
consideration, after classifying the several grand divisions of future
ocean traffic, and noting especially the needs of the United States, he
claimed that while there was little to choose, in this respect, between
Nicaragua and Tehuantepec, either was far superior to Panama.

In the second particular he maintained that owing to the characteristics
of the Panama Canal and the practical impossibility of enlarging it
hereafter, excepting at stupendous cost, it could not serve the purposes
of the future, although it might, if completed, supply present need. He
praised the ingenuity of the plans for the Ship Railway, but emphasized
the fact that it will be the _movement of the traffic_, not merely the
lifting and supporting of ships in transit, that will test the system,
and suggested that even the beautiful application of mechanical force
which had been contrived might be powerless to insure the high grade of
service which is an absolute necessity. In this connection the general
features of the Nicaragua Canal, in its latest form, were referred to,
and the opinion expressed that even were all difficulties in the way of
the Ship Railway eliminated, it could not be superior to the canal in
respect of adaptiveness.

In point of political security he claimed that both Tehuantepec and
Nicaragua were reasonably free from doubts, with the advantage in favor
of the latter, while at Panama no security, for United States interests
at least, could be counted on, without the liability of a military
expenditure far exceeding the cost of the canal itself.

The matter of comparative cost of construction and operation was
discussed generally, and in conclusion the author stated that "this
all-important question is still an open one, of which the future needs of
our country justify and demand at this time a most searching scrutiny,
and moreover our interest and the interest of mankind require that before
this century closes, the best possible pathway between the Atlantic and
the Pacific shall be open to the navies of the world."

The paper was illustrated with maps and diagrams.

       *       *       *       *       *




THE MERSEY TUNNEL.


The Mersey Tunnel was lately opened by the Prince of Wales, and, as the
London _Standard_ says, after an infancy of troubles and failures, and a
ten years' middle age of inaction, the Mersey Tunnel emerges into
notoriety under the hands of Mr. James Brunlees and Mr. C.D. Fox, and of
Mr. Waddell, the contractor, as a triumph of engineering skill. The
tunnel is 1,250 yards in length. It is driven through solid, but porous,
red sandstone, through which the water has percolated in volumes during
construction, at a level of about 30 feet below the bed of the river. It
is lined throughout with blue bricks, the brickwork of the invert being 3
feet in thickness. Its transverse section is a depressed oval 26 feet in
width and 21 feet in height, and it contains two lines of railway. At a
depth of about 18 feet below the main tunnel there is a continuous
drainage culvert 7 feet in diameter, entered at intervals by staple
shafts. There are two capacious underground terminal stations 400 feet
long, 50 feet broad, and 38 feet high, and gigantic lifts for raising 240
passengers in forty seconds, from more than three times the depth of the
Metropolitan Railway to the busy streets above. These splendid lifts, the
finest in the world, are now, through the engineering skill of Messrs.
Easton & Anderson, like the tunnel, accomplished facts; and their
construction and working were tested and reported on in high terms of
favor by the Government Inspector, General Hutchinson, a few weeks ago.
At the Liverpool end the direct descent to the underground platform of
the Mersey Railway is about 90 feet; at the Birkenhead end the depth is
something more.

The description of the Liverpool lifts will well suffice also for the
Birkenhead lifts. The former are under James Street, where above ground,
rising in lofty stateliness, is a fine tower for the hydraulic power, the
water being intended to be stored in a circular tank near its summit, the
dimensions of which will be 15 feet in diameter and its internal depth 9
feet. From the level of the rails of the Mersey Railway to the bottom of
this water-tank the vertical distance is 198 feet. At the western side of
the subterranean railway there is, above the arrival platform, a "lower
booking-hall," or, more properly, a large waiting room, 32 feet square
and 29 feet high, the access to which on this side is by a broad flight
of steps rising 12 feet, and to and from which all passengers on the
departure platform have communication by a lattice bridge 16 feet above
the line of rails. From the western side of this hall the passengers will
have access to the three lifts, and will thence ascend in large ascending
rooms or cages, capable of containing one hundred persons each, to the
upper booking-hall on the ground level of James Street. Intermediate in
height between the lower and upper halls the engine-room for the pumps is
located. From the lower hall also there is provided, independent of the
lifts, an inclined subway, leading up toward the Exchange. In this lower
subterranean chamber there are four doorways, 5 feet wide, three of them
being fitted with ticket gateways, and leading to the three lift-shafts,
excavated in the rock, and lined, where needed, with brick. In each of
these shafts, which are 21 feet by 19 feet in sectional area, a handsome
ascending wood-paneled room, or cage, formed of teak and American oak, is
fitted, its dimensions in plan being 20 feet by 17 feet, and its general
internal height 8 feet; but in the central portion the roof rises into a
flat lantern 10 feet high, the sides of which are lined with mirrors that
reflect into the ascending-room the rays of a powerful gas-lamp. The
foundation of this room is a very stiff structure, consisting of two
wrought-iron special-form girders crossing beneath it, the cross, 14
inches deep, connecting them being of steel, and forged from a single
ingot. The central boss of the cross is 22 inches in diameter, and in
this is bored out a central cavity, into which the head of the steel ram,
18 inches in diameter, is fitted; the ram itself being built up of steel
cylinders or tubes, 11 feet 3 inches in length, which are connected
together by internal screws. There is also a central rod within the ram,
as an additional security. The ram descends into a very strong cast-iron
cylinder, 21 inches internal diameter, which is suspended in a boring 40
inches internal diameter, and carried down to a depth of over 100 feet in
the rock. The two iron girders under the frame of the ascending-room or
cage cross the entire lift space, and then at their outer ends are
attached to four chains which rise over pulleys fixed about 12 feet above
the floor of the upper booking-office. These chains thence descend to
suspend two heavy counterweights, so arranged as to work in guides and to
pass the ascending-room in the 12 inch interspace between the cage and
the side walls of the shaft. These chains are of 1-1/8 inch bar iron, and
have each been tested with a load of over 15 tons. The maximum load which
can ever come as a strain upon any chain is about three tons. Two chains
are attached to each counter-weight, and special attention has been paid
to the attachments of these chains to the cage girders. The stroke of
each hydraulic lift is 96 feet 7 inches. In the engine-room there are
three marine boilers, each 6 feet 6 inches diameter and 11 feet 6 inches
long, and three pairs of pumping engines of patented type, each capable
of raising thirty thousand gallons of water per hour from the waste tanks
below the engine-room to the top tank of the tower above ground. There
are three suction and three delivery mains, and these are connected
direct to the lifts by a series of change sluices, admirably, neatly, and
handily arranged in the engine-room by Mr. Rich, and in such a way that
any engine, any lift, or any supply main can be disconnected without
interference with the rest of the system. When the tower tank is
completed, it alone, under any circumstances, would be able to supply the
lifts if every pumping engine were stopped. But if any or all the engines
were working, they would automatically assist the top tank, for nominally
they will keep the top tank exactly full, and will then stop of
themselves. The tower, as we have indicated, is not yet completed, and
the pumping engines are consequently doing all the work of the lifts. The
ascent and descent of the cages is effected by the attendant who
accompanies the passengers, by means of a rope arrangement.

Each cage or room is intended ordinarily to take a maximum freight of 100
passengers, calculated at about 15,000 lb. The hydraulic ram weighs about
11,000 lb., the iron frame and cross of the cage about 6,500 lb., and the
cage itself about 13,200 lb., the total being about 30,700 lb. The mass
in motion when a cage is fully loaded is estimated at 63,000 lb. dead
weight. The journey of elevation will ordinarily be made within one
minute, but in the experimental trials which have been made the full
journey has actually been accomplished in 32 seconds. In the Board of
Trade tests under General Hutchinson, weights to the extent of 15,000 lb.
were variously shifted, and in certain cases concentrated in trying
localities, but the cage stood the trials without any appreciable change
of form, and in neither the cage nor the chains were any objectionable
features developed. The three lifts can be worked singly or combined, so
that the accommodation is always ready for from 100 to 300 persons.
Further railway connections between the Mersey Subaqueous Railway and the
surrounding land lines than those which yet exist are in contemplation.

All the booking-halls, waiting-rooms, etc., etc., in connection with the
four stations have been laid with Lowe's patent wood-block flooring. The
blocks are only 1-1/2 inches thick, but, being made of hard wood and
securely fastened to the concrete bed with Lowe's patent preservative
composition, they cannot become loose, and will wear for a long series of
years, until, in fact, the wood is made too thin by incessant traffic.

The engineer, Mr. Fox, and the architect, Mr. Grayson, are much pleased
with the work, especially as it is so noiseless and warm to the feet.
These floors ought to be adopted more frequently by railway companies in
connection with their station buildings, as "dry rot" and "dampness" are
effectually prevented, and a durable and noiseless floor secured.

       *       *       *       *       *




IMPROVED REVOLVER.


The Kynoch revolver, manufactured by the Kynoch Gun Factory, at Aston,
Birmingham, is the invention of Mr. Henry Schlund. It may be regarded as
the most simple in respect of lock mechanism of any existing revolver,
whether single or double action. It extracts the cartridges
automatically, and combines with this important feature strength and
safety in the closing of the breech. Certainty of aim when firing is
obtained by means of a double trigger, which serves many purposes. This
secures quick repeating as in the double-action revolvers, and at the
same time the revolver is not pulled out of the line of sight, as the
trigger is pulled off by the forefinger, independently of the cocking
motion, the cocking trigger being longer than the ordinary double-action
triggers. The cocking trigger further serves to tighten the grasp, and so
enables the power of the first recoil, which affects the shooting of all
revolvers, to be held in check. The light pull-off enables a steady
shooter to make surpassingly fine diagrams.

[Illustration: THE KYNOCH REVOLVER.]

The upper side of the barrel is perfectly free from obstruction, so that
the sighting can be done with the greatest ease, and the entire weapon is
flush and without projections which can catch surrounding objects, with
the exception of the cocking trigger, which seems to require a second
guard to render it secure when thrusting the pistol hastily into a
holster. At the same time, it should be remembered that the cocking
trigger does not effect the firing. It puts the hammer to full cock and
rotates the cylinder, and these operations may be performed time after
time with safety.

Turning to the mechanical details, it is noticeable that no tools are
required to take the weapon to pieces and to put it together. By removing
a milled headed screw seen to the left of the general view, every
individual part of the lock action comes apart, and can be cleaned and
put together again in a few minutes. This screw is numbered 24 in Fig. 4.
To load the pistol the thumb piece (marked 2 in Fig. 4 and shown
separately in Fig. 3) is drawn back, and thus withdraws the sliding bolt,
3, from the barrel, 20. The barrel and cylinder are then tilted on the
pin, 15--a shake will effect this if only one hand be available--and as
the chamber rises, the extractor is forced back by the lifter, 15, and
the empty shells are thrown out. When the barrel has moved about 80 deg.,
the spring, 14, which works the lifter, 15, is tripped, and the spring 13
carries the extractor home ready for the fresh cartridge to be inserted.
When these are in place, the barrel and cylinder are returned to the
position shown in Fig. 1, and are automatically locked by the bolt, 3.
All is then ready for firing. The middle finger is placed on the cocking
lever, and the forefinger within the trigger guard. The cocking trigger
is drawn back, taking with it the firing trigger for the greater part of
its stroke. At the same time the lifter, 8, which is pivoted to the
cocking lever, engages with a ratchet wheel (seen in Fig. 2) attached to
the cylinder, and rotates it through one-sixth of a revolution. To insure
the exact amount of rotation, a heel on the trigger, not to be seen in
the engravings, engages in one of the six slots (Figs. 1 and 2) formed
round the barrel. The end of the slot is square, and comes up against the
heel, which tightly grips the cylinder, and holds it steady while firing.
A toe-piece, just over the figure 4, in Fig. 3, holds the cylinder when
the cocking trigger is in its normal position. The cocking lever also
compresses the main spring, 7, and holds it in this state until the
firing trigger, 12, is pressed by the forefinger against the sear, 9, and
the hammer, 5, is driven forward against the cartridge. If the pistol be
not fired, the release of the cocking trigger takes the pressure off the
spring, and there is thus no danger of accidental discharge.

It will thus be seen, says _Engineering_, that the weapon presents many
advantages. It can be loaded on horseback when one hand is engaged with
the reins; there is nothing to obstruct the aim, and the act of firing
does not throw up the muzzle, for the two operations of cocking and
shooting are separate, and consequently the latter needs only a very
light pressure of the finger to effect it. The breech is well protected,
so that the flash from a burst cartridge cannot reach the face of the
user. The mechanism is as nearly dust proof as possible, and can be
entirely taken to pieces and cleaned in a few moments, and the whole
forms as handy a weapon as can be desired, where rapid and accurate
shooting is required.

       *       *       *       *       *




[JOURNAL OF THE SOCIETY or ARTS.]

MOTORS FOR STREET RAILWAYS.

RESULTS OF EXPERIMENTS ON MECHANICAL MOTORS FOR TRAMWAYS MADE BY THE
JURY ON RAILWAY APPLIANCES AT THE ANTWERP EXHIBITION.

By Captain DOUGLAS GALTON, D.C.L., O.B., F.R.S.


An interesting feature of the International Exhibition at Antwerp was the
competition which was invited between different forms of mechanical
motors on tramways for use in towns, and between different forms of
engines for use on light railways in country districts, or as these are
termed, "Chemins de Fer Vicinaux."

These latter have obtained a considerable development in Belgium, Italy,
and other Continental states; and are found to be most valuable as a
means of cheapening the cost of transit in thinly peopled districts. But
owing to the fact that the Board of Trade regulations in this country
have not recognized a different standard of construction for this class
of railway from that adopted on main lines, there has been no opportunity
for the construction of such lines in England.

There has, however, been a great development of tramway lines in England,
which in populous districts supply a want which railways never could
fully respond to; and although hitherto mechanical traction has not
attained any very considerable extension, it is quite evident that if
tramways are to fullfil their object satisfactorily, it must be by means
of mechanical traction.

It is also certain that the mechanical motor which shall be found to be
most universally adaptable, that is to say, most pliant in accommodating
itself to the various lines and to the varying work of the traffic, will
be the form of motor which will eventually carry the day.

The competition between different forms of motors at the Antwerp
Exhibition, which was carefully superintended, and which was arranged to
be carried on for a reasonable time, so as to enable the qualities and
defects of the different motors to be ascertained, affords a starting
point from which it will be possible to carry on future investigations.

I have, therefore, thought it advantageous to the interests of the
community in this country to bring the results arrived at before this
Society; and as the "Chemins de Fer Vicinaux," to which one part of the
competition was devoted, have no counterpart in this country, it is
proposed to limit the present paper to an account of the experiments made
on the motors for tramways.

Certain conditions were laid down in the programme published at the
opening of the Exhibition, to regulate the competition, in order that the
competitors might understand the points which would be taken into account
by the judges in awarding the prizes.

The experiments were made upon a line of tramway laid down for the
purpose in the city of Antwerp, carried along the boulevards from near
the main entrance of the exhibition to the vicinity of the principal
railway station, a distance of 2,292 meters.

The line ended in a triangle of 505 meters, in order that those motors
which required to run always in the same direction should be enabled to
do so.

Out of the whole length of the line, viz., 2,797 meters, 2,295 meters
were in a straight line, 189 meters in curves of 1¾ chains radius, and
313 meters in curves of 1 chain radius. There were on the line four
passing places, besides a passing place at the terminus; these were
joined to the main line by curves of 1¾ chains radius.

The line was practically level, the steepest incline being 1 in 1,000;
this circumstance is somewhat to be regretted, but the city of Antwerp
afforded no convenient locality where a line with steep gradients could
have been obtained. The motors were kept in sheds close to the
commencement of the line of tramway near the exhibition, where all
necessary cleaning and such minor repairs as were required could take
place.

A regular service was established, according to a fixed time-table, to
which each motor was required to conform. Each journey was reckoned as
starting from the end near the exhibition, proceeding to the beginning of
the triangle, and returning to the starting point. An hour was allowed
between the commencement of each journey, fourteen minutes were allowed
for a stoppage at the end near the exhibition, and eighteen minutes at
the other end--thus allowing twenty-eight minutes for traveling 2 miles
1,500 yards, or a traveling speed of about 6 miles an hour. The motors
were required to work four days out of six, and on one of the four days
to draw a supplementary carriage.

An official, assisted by a storekeeper, was appointed to keep a detailed
record--

  1. Of the work done by each of the motors.
  2. Of any delays occurring on the journey, and of the
     causes of delay.
  3. Of the consumption of fuel, both for lighting the
     fires and for working.
  4. Of the consumption of grease.
  5. Of the consumption of water.
  6. Of all repairs of whatever nature.
  7. Of the frequency of cleaning and other necessary
     operations required for the efficient service of the
     motor.

The experiments lasted about four months. Five competitors offered
themselves, which may be classed as follows: Three were propelled by the
direct action of steam, and two were propelled by stored-up force
supplied from fixed engines.

_Propelled by the direct action of the steam._
  1. The Krauss locomotive engine, separate from the carriage.
  2. The Wilkinson locomotive engine (i.e., Black and
     Hawthorn), also separate from the carriage.
  3. The Rowan engine and carriage combined.

_Propelled by stored-up force._
  4. The Beaumont compressed-air engine.
  5. The electric carriage.

It is somewhat to be regretted in the public interest that other forms of
mechanical motors, such as the Mekarski compressed-air engine, or the
engine worked with superheated water, or cable tramways, or electrical
tramways, were not also presented for competition.

1. The Krauss locomotive is of the general type of a tramway locomotive,
but with certain specialties of construction. It has coupled wheels. The
weight is suspended on three points. The water-tanks form part of the
framing on each side; a covering conceals all except the dome of the
boiler. Above the roof is a surface condenser, consisting of 108 copper
tubes placed transversely, each of which has an external diameter of 1.45
inches. The boiler is similar to that of an ordinary locomotive; its axis
is 3 feet 10½ inches above the road. The body of the engine is 9 feet 11
inches long, and 7 feet 2½ inches wide. The axles are 4 feet 11 inches
from center to center. The platform extends along each side of the
boiler; the door of the fire-box is in the axis of the road. The engine
driver stands on the right-hand side, in the middle of the motor, where
he has command of all the appliances for regulating the movements of the
engine as well as of the brake.

The Wilkinson (Black and Hawthorn) engine had a vertical boiler and
machinery. The cylinders were on the opposite side of the boiler from the
door of the fire box, and mounted independently; the motion of the piston
was communicated by means of a crank shaft and toothed wheels to the
driving axle. The wheels were coupled. A regulator, injector, and a
hand-brake were placed at each end, so that the engine driver could
always stand in the front, whichever was the direction in which the
engine moved; and there was a platform of communication between the two
ends, carried along one side of the boiler.

The boiler was constructed with "Field" tubes, the horizontal tube plate
having a flue in the middle which carried the heated gases into the
chimney.

The visible escape of the steam is prevented by superheating. To effect
this, the steam, as it leaves the cylinder, passes into a cast iron
chamber adjacent to the boiler, which is intended to retain the water
carried off with the steam. From thence the steam passes into a second
chamber, suspended at a small height above the grate in the axis of the
boiler and of the flue which conveys the heated gases into the chimney,
and thence into a sort of pocket inclosed in the last-mentioned chamber,
which is open at the bottom, and the upper part of which terminates in a
tube passing into the open air. This method of dissipating the steam
avoids the necessity of a condenser; but if it be admitted that the steam
in escaping has a minimum temperature of 572° Fahr., it will carry away
12 per cent. more caloric than would have been required to raise it to a
pressure of 150 lb. per square inch.

The steam escaping through the safety valve is passed through the same
apparatus.

The toothed wheel on the driving axle is arranged to act upon another
toothed wheel on a shaft connected with the regulator, so as to control
its speed automatically.

The length of the engine is 10 ft. 10 in., its width 5 ft. 9 in., and the
distance from center to center of the wheels 5 ft. 2 in.

The Rowan tram-car consists of a body 31 feet long and 7 feet wide,
resting on a two-wheeled bogie behind and on a four-wheeled bogie in
front, this front bogie being the motor, and the whole has the appearance
of a long railway carriage, somewhat in the form of an omnibus with a
platform at each end, of which the front platform is occupied by the
engine. It requires, therefore, either a turntable or a triangle at the
end of the line, so as to enable it to reverse its direction.

This motor is a steam engine of light and simple form, supplied with
steam from a water tube boiler with very perfect combustion, so that no
smoke escapes. The boiler is somewhat on the principle of a Shand and
Mason boiler; it is so built that It can easily be opened and every part
of the interior examined and cleaned.

The peculiarity of the Rowan motor is the simplicity of the attachment of
the engine to the carriage, and the facility with which it can be
detached when required for cleaning or repair, viz., in five or six
minutes.

The steam can be got up in the engine with great rapidity if a change of
engine is required. When, however, the engine is detached, the carriage
loses its support in front, and is therefore not serviceable. When
necessary, the combined motor can draw a second ordinary carriage.

The motor by itself occupies a length of 9 ft. 8 in. It has two
horizontal cylinders; the four wheels of the bogie are coupled, and
between the wheels the sides of the framing are rounded to allow two
vertical boilers to stand. These boilers have vertical tubes for the
water, which are joined together at the top by a horizontal cylinder.
Each boiler, with its covering, is 1 ft. 9 in. in diameter. The boilers
stand 1 ft. 9 in. apart, thus affording space between them for the motive
machinery, including the pump. The crank axle is behind the boilers. The
levers, the injector, the access to the fire-box, a pedal for working the
engine brake as well as a screw brake for the carriage, are all in front.
The brakes act on all six wheels, are worked by the driver, and the whole
weight of the engine, car, and passengers being carried on these wheels,
the car can be stopped almost instantaneously; and as over two-thirds of
the entire weight of the car and passengers rests on the four driving
wheels; there is always sufficient adhesion on all reasonable inclines,
and the adhesion is augmented as the number of passengers carried
increases. Hence this car is adapted for lines with heavy grades.

A small water tank is attached to the framing; two small boxes for coal
or coke, with a cubic capacity of about 3½ feet, are attached to the
plate in front of the bogie. The covering of the boilers is in two parts,
which are put on from each side horizontally, and screwed together in the
center. The removal of the upper part enables the tubes to be examined
and cleaned. The draught is natural; the base of the chimney is 3 ft. 2
in, from the grate; the height of the chimney is 5 ft. 2 in.

The steam from the cylinders passes directly into a condenser placed on
the top of the carriage. The condenser is made of corrigated copper
sheets millimeter thick. Two sheets, about 15 to 18 inches wide and 15
feet long, are laid together and firmly soldered, forming a chamber.
Twenty of these chambers are placed side by side on the top of the
carriage, connected with a tube at each end, so as to allow the steam to
pass freely through them. The lower corrugations in the several chambers
are connected together, and thence a pipe with a siphon to stop the steam
is carried to a water tank under the carriage, which thus receives the
condensed water. This arrangement afforded a condensing surface of about
800 square feet. It should be mentioned that with larger engines Mr.
Rowan employs as much as 1,600 feet of condensing surface. The nearness
of the chambers to each other tends no doubt to diminish the power of
condensing the steam, but this is somewhat compensated by the artificial
circulation of air produced by the movement of the carriage. But in any
case, if there is surplus steam, the pipe from the condenser causes it to
pass under the grate, whence it rises superheated and invisible through
the fire and up the chimney.

Under the carriage attached to the framing are four reservoirs, holding
about three and a half cubic feet of water, of which water space one-half
acts as a reservoir for cold feed water, and half for the condensed
water. A tube from the small reservoir on the engine communicates through
valves with the reservoirs of hot and cold water on the carriage.

The consumption of cold water measured during two days was 2.86 lb. per
kilometer; assuming that the boiler evaporated 6.5 lb. of water per pound
of coal, the cold water formed one-fifth of the total feed water
required.

The carriage, i. e., the part occupied by passengers, is 21 ft. 8 in. in
length. It holds seats for forty-five passengers, besides those who would
stand on the gangway and platform. The seats are placed transversely on
each side of a central corridor, each seat holding two people. The
platform of the carriage is about 2 ft. 6 in. above the rails. Passengers
have access to the interior from behind by means of the end platform, and
in front near the engine from the two sides. As already mentioned, the
hind part of the carriage rests upon two wheels, the front part being, as
already mentioned, supported on the engine bogie. To effect this support,
the hinder part of the framing of the engine is formed in a half circle,
with a broad groove, in which the ends of two springs are arranged to
slide. The centers of the springs form the support of the framing of the
carriage.

The framing of the engine bogie is attached to the hind bogie truck of
the carriage by two diagonal drawbars. The coupling is effected by bolts
close to the engine, and the car is drawn entirely by means of the bogie
pin of the hind bogie. The trucks are 16.5 ft. apart.

Table I. above shows the dimensions of different parts of these three
steam motors, as well as their weights.

The Beaumont engine, worked by compressed air, may be generally said to
be similar to that described in a paper read before the Society of Arts
on the 16th March, 1881, to which, however, some improvements have been
since introduced.

The apparatus for compressing the air was placed in the shed. The air was
compressed to 63 atmospheres by a pump worked by a steam engine, and
stored in cylindrical reservoirs of wrought iron without rivets. A pipe
led the air from the reservoirs to the head of the tramway, where the
cylinder placed on the motor for storing the air during the journey could
be conveniently charged.

The air was compressed by means of four pumps, placed two and two in a
water-box, and worked by the direct action of a compound engine, with
cylinders, placed in juxtaposition, of 8 in. and 14 in. diameter
respectively, with an equal length of stroke of 13 in.

TABLE I.

                                    Krauss.      Wilkinson.       Rowan.
Diameter of cylinder.........d       5.5 in.       6.5 in.        5.1 in.
Length of stroke.............l      11.8 in.       9   in.        9.8 in.
Diameter of wheels...........D      31.5 in.      27.5 in.       29.5 in.
Pressure at which
  boiler is worked...........P     220 lb.       147 lb.         191 lb.
(p(d^{2})l)/(2D).............E   1,210 lb.     1,509 lb.         805 lb.
Total heating surface........S     105 sq. ft.   105 sq. ft.    64 sq. ft.
Grate surface................G     2.7 sq. ft.   5.4 sq. ft.   3.1 sq. ft.
Surface of condenser.........C  274.482 s. ft.   None.      861.120 s. ft.
Weight in running order
  (motor only)...............P' 15,400 lb.    15,400 lb.       9,020 lb.
Weight in running order
  (total)....................P"       -              -        15,400 lb.
Contents of water tank.......-  28.24 cub. ft.   13 cub. ft.  4.2 cub. ft.
Contents of coal bunks.......-  14.12 cub. ft. 12.5 cub. ft.  8.5 cub. ft.
                           P'/E   12.7 lb.      10.2 lb.        11.2 lb.
                           P"/E       -              -        19.125 lb.
                           P'/S    146             147          140
                           P'/G  5,722           2,855        2,889
                            C/S      2.6             -            13.4
                            C/G    102               -           275

The air, after being forced through the first pump cylinder, passed
successively through the other three, the diameters of which were of
proportionately decreasing sizes, viz., 8.2 in., 5 in., 3.5 in., and 2
in., and the air on leaving each cylinder passed on its way to the next
cylinder through a coiled pipe immersed in flowing water to remove the
heat generated. This cooling surface amounted to nearly 54 sq. ft.

The cooling of the air was very efficient. In an experiment made on this
question, the temperature of the compressor did not vary to the extent of
9° F. in charging the reservoir from 40 to 63 atmospheres, occupying an
hour and a half, the consumption of water during the time being about
1,400 gallons.

The fixed reservoirs were of about 240 cubic feet capacity.

The motor formed part of a compound vehicle, which may be said to have
consisted of two parts joined together by an articulated corridor, the
whole being covered by a roof which was approached from the platform
behind by an easy staircase. On this roof were seats for outside
passengers.

The front part of the compound vehicle contained the motor, as well as a
compartment for six inside passengers, with roof space for twenty
passengers, and weighed about 15,400 lb. when empty; the hind part
contained accommodation inside for twelve passengers, and outside for
fourteen passengers, and weighed 6,600 lb.

The combined vehicle was entered from the platform in the rear, which
could hold four passengers, and from thence, as already mentioned, the
staircase led on to the roof. The total number of passengers this vehicle
could accommodate was thus eighteen inside, thirty-four on the roof, four
on the platform, or fifty-six in all.

The total length of the carriage was 29 ft. 7 in., the width 7 ft. The
distance between the axes of the bogies was 16 ft. 9 in. The distances
apart of the centers of the wheels were in the case of the hind bogie 3
ft. 9 in., and in the case of the front bogie 4 ft. 4.6 in.

The motor is a compound engine, the diameters of the cylinders being 4.9
in. and 1.9 in., with a 12 in. stroke. The diameter of the wheels was 2
ft. 4 in. A small boiler is placed on one side, in front, for creating
steam, which passes into a steam-jacket, inclosing the pipe of
communication from the reservoir to the cylinders, as well as the
cylinders themselves, so that the air was warmed before it escaped. The
reservoirs on the motor contained 71 cubic feet.

In an experiment made on charging the reservoir in the motor, the
pressure in the fixed reservoirs, at the time of charging the reservoirs
on the motor, was 63.8 atmospheres, at a temperature of 68° F. One
atmosphere was lost by letting the air into the pipe laid between the
shed and the tramway where the motor stood; when the reservoir on the
motor was charged, the pressure fell to 42.6 atmospheres in the fixed
reservoirs, at a temperature of 55° F.

The pressure in the reservoir on the motor, when ready to start, was 42.6
atmospheres, at a temperature of 84° F. On its return, at the end of
forty-six minutes, after a journey as above mentioned of about three and
a quarter miles including the triangle, the pressure had fallen to 20.9
atmospheres, and the temperature to 71° F. The weight of air used during
the journey was thus about 110 lb., or, say, 34 lb. per mile. The coal
consumed by the stationary engine to compress the air amounted to 39 lb.
per mile, in addition to 3 lb. of coke per mile for warming the exhaust.

While the motor was performing its journey, the stationary steam-engine
was employed in raising the pressure in the fixed cylinders to 63
atmospheres, and worked, on an average, during fifty minutes in each
hour; during the rest of the journey it remained idle. It was thus always
employed in doing work in excess of the pressure which could be utilized
on the car, and the work was, under the circumstances of the case,
necessarily intermittent. This was a very unfavorable condition of
working.

In the electric tram-car the haulage was effected by means of
accumulators. The car was of the ordinary type with two platforms. It was
said to have been running as an ordinary tram-car since 1876. It had been
altered in 1884 by raising the body about six inches, so as to lift it
clear of the wheels, in order to allow the space under the seats to be
available for receiving the accumulators, which consisted of Faure
batteries of a modified construction. The accumulators employed were of
an improved kind, devised by M. Julien, the under manager of the
Compagnie l'Electrique, which undertook the work.

The principal modification consists in the substitution, for the lead
core of the plates, of one composed of a new unalterable metal. By this
change the resistance is considerably diminished, the electromotive force
rises to 2.40 volts, the return is greater, the output more constant, and
the weight is considerably reduced. The plates being no longer subject to
deformation have the prospect of lasting indefinitely. The accumulators
used were constructed in August, 1884.

The car, as altered, had been running as an electric tram-car on the
Brussels tramways since October, 1884, till it was transferred to the
experimental tramway at Antwerp. The accumulators had been in use upon
the car during the whole of this period, and they were in good order at
the end of the experiments, that is to say, when the exhibition closed at
the end of October, 1885.

The accumulator had forty elements, divided into four series, each series
communicating, by means of wires fixed to the floor of the car, with
commutators which connected them with the dynamo used as a motor.

There were two sets of these batteries or accumulators, one of which was
being charged in the shed while the other was in use. The exchange
required ten minutes, including the time for the car to go off the
tramway into the shed and return to the tramway. This exchange took place
after every seven journeys. Therefore, the two batteries would have
sufficed for working the car over a distance of about forty-two miles
during sixteen hours.

It may be observed that the first service in the morning would be
performed by means of the accumulators charged during the afternoon and
evening of the previous day.

Each element of a battery was composed of nineteen plates, of which nine
were positive, four millimeters thick, and ten negative, three
millimeters thick. Each positive plate weighed 1.44 lb., of which about
twenty-five per cent. consisted of active material. Each negative plate
weighed nearly 1 lb., of which one-third consisted of active matter. The
weight of the metallic part of the battery amounted, therefore, to 1,846
lb.; and the whole battery, including the case and the liquid, amounted
to 2,464 lb., which contained 499 lb. of active matter, or about 20.25
per cent. The four cases in which the battery was contained were so
arranged as to divide the weight equally between the wheels.

Two commutators inclosed in a box were placed on the platforms at the two
ends of the carriage, so as to be available for moving in either
direction.

The accumulators were divided into four series of ten double elements,
which, by means of the commutators, could be united under four
combinations, viz.:

 1st.  4 series in quantity--1 in tension.
 2d.   2    "    "    "      2     "
 3d.                         3     "
 4th.                        4     "

Finally, a fifth movement united the four series in quantity, coupling
them on each other, and putting the dynamo out of circuit, thus restoring
equilibrium. When in a state of repose, the handle was so arranged as to
keep this latter switch turned on. The accumulators were arranged for
charging in two series united in quantity, each containing twenty double
elements. The charge was effected by a Gramme machine, worked by a
portable engine. Each of these series received its charge during seven
hours for the ordinary service of the car, and during nine hours for the
accelerated service.

The accumulators on the car actuated a Siemens dynamo, acting as a motor,
such as is used for lighting, having a normal speed of 1,000 revolutions,
fixed on the frame of the carriage. The motion was conveyed from the
pulley on the dynamo by means of a belt passing round a shaft fixed on
movable bearings to regulate its tension, and thence to the axles by
means of a flat chain of phosphor bronze. The chain was adopted as the
means of moving the axle, on account of its simplicity and facility of
repair by unskilled labor.

The speed was fixed at 4 meters per second (which corresponds with a
speed of nearly 9 miles per hour) for 1,000 revolutions of the dynamo;
and it was regulated by cutting a certain number of the accumulators out
of circuit, instead of by the device of inserting resistances, which
cause a waste of energy. By breaking the circuit entirely the motive
power ceased, and the vehicle might either be stopped by the brakes or
allowed to run forward by gravity, if the road were sufficiently
inclined. The reversal of the motor was effected by means of a lever
which reversed the position of the brushes of the dynamo.

The dynamo could be set in motion, and the carriage worked from either
end, as desired. The handle to effect this was movable, and as there was
only one handle, and this one was in charge of the conductor, he used it
at either end as required.

It should be mentioned that the car was lighted at night by two
incandescent lamps, which absorbed 1.5 amperes each; and the brakes also
were worked by the accumulators.

The weight of the tram-car was 5,654 lb.; the weight of the accumulators
was 2,460 lb.; the weight of the machinery, including dynamo, 1,232 lb.
The car contained room for fourteen persons inside and twenty outside.
Under the conditions of the competition the car was required to draw a
second car occasionally.

The jury made special observations upon the work required to move the car
between the 20th September and 15th October, 1885. Seals were attached to
the accumulators. Moreover, from the 27th of September, after each
charge, seals were placed on the belts from the steam-engine to prevent
any movement of the Gramme machine, so that there could be no charges put
into the accumulators beyond those measured by the jury.

The instruments used for measuring were Ayrton's amperemeter and Deprez's
voltmeter, which had been tested in the exhibition by the Commission for
Experiments on Electrical Instruments, under the presidency of Professor
Rousseau. Besides this, Siemens' electro-dynamometer and Ayrton's
voltmeter were used to check the results; but there was no practical
difference discovered. During the period of charging the accumulators,
the intensity of the current and the electromotive force was measured
every quarter of an hour, and thence the energy stored up in the battery
was deduced. It may be mentioned that the charge in the accumulators,
when the experiments were commenced, was equal in amount to that at their
termination.

An experiment was made on 21st October to ascertain, as a practical
question, what was the work absorbed by the Gramme machine in charging
the accumulators. The work transmitted from the steam-engine was measured
every quarter of an hour by a Siemens dynamometer; at the same time the
intensity of the electromotive force given out by the machine, as well as
the number of the revolutions it was making, was noted. It resulted that
for a mean development of 4 mechanical horse power, the dynamometer gave
into the accumulators to be stored up 2.28 electrical horse power, or 57
per cent. The intensity varied between 25.03 and 23.51 amperes during the
whole time of charging. Of this amount stored up in the accumulators a
further loss took place in working the motor; so that from 30 to 40 per
cent. of the work originally given out by the steam-engine must be taken
as the utmost useful effect on the rail.

It was estimated that to draw the carriage on the level 0.714 horse power
was required, or if a second carriage was attached, 0.848 horse power
would draw the two together. This would mean that, say, 2 horse power on
the fixed engine would be employed to create the electricity for
producing the energy required to draw the carriage on the level.

The electric tram-car was quite equal in speed to those driven by steam
or compressed air, and was characterized by its noiselessness and by the
care with which it was manipulated.

Assuming the car, by itself, cost the same as an ordinary tram-car, the
extra cost relatively to other systems was stated as being according to
the following figures, viz.: the Gramme machine cost £48, the motor £208,
and the accumulators 2.25 francs per kilogramme (10d. per pound). To
these must be added the cost of erection, and of switches for
manipulating the current; as well as the proportion of the cost of a
fixed engine to create the electricity.

Having thus given a general description of the various motors which were
presented for competition, I will now give a brief summary of some of the
principal particulars obtained during the competition. In the first
place, it may be mentioned that the jury consisted of the following:

President.--M. Hubert, Ingénieur en Chef, Inspecteur de Direction à
l'administration des chemins de fer de l'Etat Belge.

Vice-President.--M. Beliard, Ingénieur des Arts et Manufactures, délégué
par le Gouvernenent Français.

Members.--MM. Douglas Galton, Capitaine du Génie, délégué par le
Gouvernement Anglais; Gunther, Ingénieur, Commissaire Général de la
Section allemande à l'Exposition d'Anvers; Huberti, Ingénieur à
l'administration des chemins de fer de l'Etat Belge, Professeur à
l'Université de Bruxelles; Dery, Ingénieur Chef de service à
l'administration des chemins de fer de l'Etat Belge.

Secretary.--M. Dupuich, Ingénieur Chef du service du matérial et de la
traction à la Société Générale des chemins de fer économiques.

Reporter.--M. Belleroche, Ingénieur en Chef, à la traction et au matérial
des chemins de fer du Grand Central.

Members added by the Jury.--MM. Vincotte, Ingénieur, Directeur de
l'Association pour la surveillance des machines à vapeur; Laurent,
Ingénieur des mines et de l'Institut électro-technique de l'Université de
Liége.

The original programme of the conditions which were laid down in the
invitation to competitors, as those upon which the adjudication of merit
would be awarded, contained twenty heads, to each of which a certain
value was to be attached; and, in addition to these special heads, there
were also to be weighed the following general considerations, viz.:

a. The defects or inconveniences established in the course of the trials.

b. The necessity or otherwise of turning the motor, or the carriage with
motor, at the termini.

c. Whether one or two men would be required for the management of the
engine.

As regards these preliminary special points, the compressed air motor, as
well as the Rowan engine, required to be turned for the return journey,
whereas the other motors could run in either direction.

In regard to this, the electric car was peculiarly manageable, as it
moved in either direction, and the handle by which it was managed was
always in front, close to the brake. This carriage was the only one which
was entirely free from the necessity of attending to the fire during the
progress of the journey, for even the compressed air engine had its small
furnace and boiler for heating the air.

Each of the motors under trial was managed by one man.

The several conditions of the programme may be conveniently classified in
three groups, under the letters A, B, C. Under the letter A have been
classed accessory considerations, such as those of safety and of police.
These are of special importance in towns. But their relative importance
varies somewhat with the habits of the people as well as with the
requirements of the authorities; for instance, in one locality or country
conditions are not objected to which, in another locality, are considered
entirely prohibitory.

    The conditions under this head are:
    1. Absence of steam.
    2. Absence of smoke and cinders.
    3. Absence, more or less complete, of noise.
    4. Elegance of aspect.
    5. The facility with which the motor can be separated
         from the carriage itself.
    6. Capacity of the brake for acting upon the greatest
         possible number of wheels of the vehicle or vehicles.
    7. The degree to which the outside covering of the
         motor conceals the machinery from the public, while
         allowing it to be visible and accessible in all parts to
         the engineer.
    8. Facility of communication between the engineer
         and the conductor of the train.

In deciding upon the relative merits of the several motors, so far as the
eight points included under this heading are concerned, it is clear that,
except possibly as regards absence of noise, the electrical car surpassed
all the others.

The compressed air car followed, in its superiority in respect of the
first three points, viz., absence of steam, absence of smoke, and
absence of noise; but the Rowan was considered superior in respect of the
other points included in this class.

Under the letter B have been classed considerations of maintenance and
construction.

    9.  Protection, more or less complete, of the machinery against the
          action of dust and mud.
   10.  Regularity and smoothness of motion.
   11.  Capacity for passing over curves of small radius.
   12.  The simplest and most rational construction.
   13.  Facility for inspecting and cleaning the interior of the boilers.
   14.  Dead weight of the train compared with the number of places.
   15.  Effective power of traction when the carriages are completely full.
   16.  Rapidity with which the motor can be taken out of the shed and
          made ready for running.
   17. The longest daily service without stops other than those
          compatible with the requirements of the service.
   18. Cost of maintenance per kilometer. (It was assumed, for the
          purposes of this sub-heading, that the motor or carriage which
          gave the best results under the conditions relating to
          paragraphs 9, 10, 12, and 13 would be least costly for repairs.)

As regards the first of these, viz., protection of the machinery against
dirt, the machinery of the electrical car had no protection. It was not
found in the experiments at Antwerp that inconvenience resulted from
this; but it is a question whether in very dusty localities, and
especially in a locality where there is metallic dust, the absence of
protection might not entail serious difficulties, and even cause the
destruction of parts of the machinery.

In respect to the smoothness of motion and facility of passing curves,
the cars did not present vary material differences, except that the cars
in which the motor formed part of the car had the preference.

In the case of simplicity of construction, it is evident that the
simplest and most rational construction is that of a car which depends on
itself for its movement, which can move in either direction with equal
facility, which can be applied to any existing tramway without expense
for altering the road, and the use of which will not throw out of
employment vehicles already used on the lines; the electric car fulfilled
this condition best, as also the condition numbered 13, as it possessed
no boiler.

In respect to No. 14, viz., the ratio of the dead weight of the train to
passengers, if we assume 154 lb. as the average weight per passenger, the
following is the result in respect of the three cars in which the power
formed part of the car:

                   9,350 lb.
Electric car.      --------- = 1.78
                    154 × 34

                  15,950 lb.
Rowan.            ---------- = 2.30
                  154 × 45

                  22,000 lb.
Compressed air.   ---------- = 2.55
                  154 × 56

The detached engines gave, of course, less favorable results under this
head.

Under head No. 15 the tractive power of all the motors was sufficient
during the trials, but the line was practically level, therefore this
question could only be resolved theoretically, so far as these trials
were concerned, and the table before given affords all the necessary data
for the theoretical calculation.

As regards the rapidity with which the motors could be brought into use
from standing empty in the shed, the electric car could receive its
accumulators more rapidly than could the boiler for heating the exhaust
of the compressed-air car be brought into use.

As regards the steam motors, the following were the results from the time
of lighting the fires:

The Rowan--
  In 34 minutes                   3 atmospheres.
   " 36    "                      4     "

     At this pressure the vehicle could move--

 In 40 minutes                    8 atmospheres.

The Wilkinson--
  In 35 minutes                   2 atmospheres.
   " 40    "                      4     "
   " 44    "                      6     "
   " 47    "                      8     "

The Krauss machine required two hours to give 6 atmospheres, which was
the lowest pressure at which it could be worked.

The results under No. 17, viz., the fewest interruptions to the daily
service, class the motors in the following order: Krauss, electric,
Rowan, Wilkinson, compressed air. The chief cause of injury to the
compressed air motor arose from the carelessness of the drivers, who
allowed the steam boiler to be burnt out. Unfortunately, these drivers
were new to the work.

Under the letter C are classed considerations of economy in the
consumption of materials used for generating the power necessary for
working.

  19.   Minimum consumption of fuel (either coke or coal),
          in proportion to the number of kilometers run, and
          to the number of places, assuming for the seats a
          width of at least sixteen inches for each person seated.

It must be borne in mind that the conditions of the competition required
that a second car should be periodically drawn by the motor, and that the
calculations which follow include the total number of miles run, the
total amount of fuel, etc., consumed, and the total number of passengers
which could be conveyed by each motor, during the total time that the
experiments were being carried on.

                           TABLE II.

                          Total
Description of motor.   number of      Total       No. of lb.
                       train miles  Consumption       per
                           run.       of fuel.     train mile.

                                        lb.
Electric.               2,358.9       14 786         6.16
Rowan.                  2,616.9       14,498         5.42
Wilkinson.              2,473.3       22,000         8.82
Krauss.                 2,457.8       22,726         9.10
Compressed air.         2,259.1       90,420        39.48

                           TABLE III.

                       No. of places                      No. of lb. of
Description of motor.  indicated on                       fuel consumed
                       the cars, per       Consumption    per places
                       mile run.             of fuel.     indicated
                                                          per mile run.
                                               lb.
Electric               80,203.5              14,786        0.18
Rowan                 148,399.6              14,498        0.09
Wilkinson             119,085.1              22,000        0.18
Krauss                108,983.9              22,726        0.20
Compressed air        128,189.3              90,420        0.69


                           TABLE IV.

Description of motor.  No. of seats per                 No, of lb. of
                       mile run.          Consumption   fuel consumed
                                          of fuel.      per seat
                                                        per mile run.
                                           lb.
Electric               61,591.2           14,786        0.23
Rowan                 135,928.8           14,498        0.10
Wilkinson              93,965.6           22,000        0.23
Krauss                 86,039.9           22,726        0.25
Compressed air        132,732.7           90,420        0.66

As regards the figures in these tables, it is to be observed that the
consumption of fuel for the electric car is, to a certain extent, an
estimate; because the engine which furnished the electricity to the motor
also supplied electricity for electric lights, as well as for an
experimental electric motor which was running on the lines of tramway,
but was not brought into competition.

20. Minimum consumption of oil, of grease, tallow, etc. (the same
conditions as in No. 19).

                           TABLE V.

                                   Total           Consumption
                     Total         consumption     of oil, tallow,
Description of       number of     of              etc.,
motor.               miles run.    oil, tallow,    per train mile
                                   etc.            run.

                                   lb.
Electric             2,358.9       99.0            0.038
Rowan, steam         2,616.9      106.7            0.038
Krauss, steam        2,457.8      188.5            0.073
Wilkinson, steam     2,473.3      255.4            0.101
Compressed air       2,259.1      585.2            0.255

In addition to these considerations, it was thought useful to investigate
the quantity of water consumed in the case of those engines which used
steam. The experiments made on this point showed as the consumption of
water:

                 Gallons per mile.
Rowan                 0.75
Compressed air        1.06
Wilkinson             5.89
Krauss                6.52

Thus, owing to the large proportion of water returned from the condenser
to the tanks, the Rowan actually used less water than the compressed air
engine.


CONCLUSION.

The general conclusion to which these experiments bring us is that,
undoubtedly, if it could certainly be relied upon, the electric car would
be the preferable form of tramway motor in towns, because it is simply a
self-contained ordinary tram-car, and in a town the service requires a
number of separate cars, occupying as small a space each as is compatible
with accommodating the passengers, and which follow each other at rapid
intervals.

But the practicability and the economy of a system of electric tram-cars
has yet to be proved; for the experiments at Antwerp, while they show the
perfection of the electric car as a means of conveyance, have not yet
finally determined all the questions which arise in the consideration of
the subject. For instance, with regard to economy, the engine employed to
generate the electricity was not in thoroughly good order, and from its
being used to do other work than charging the accumulators of the
tram-car, the consumption of fuel had to be to some extent estimated. In
the next place, the durability of the accumulators is still to be
ascertained; upon this much of the economy would depend. And in addition
to this question, there is also that of the durability of parts of the
machinery if exposed to dust and mud.

After the electric car, there is no question but that at the Antwerp
Exhibition the most taking of the tramway motors was the Rowan, which was
very economical in fuel, quite free from the appearance of steam, and
very convenient and manageable.

The economy of the Rowan motor arises in a large degree from the extent
of its condensing power, by means of which a considerable supply of warm
water is constantly supplied for use in the boiler, and consequently the
quantity of water which has to be carried is lessened, and the fuel is
economized.

Independently, however, of its convenience as a motor for tramways in
towns, the Rowan machine has been adapted on the Continent to the
conveyance of goods as well as passenger traffic on light branch
railways, and fitted to pass over curves of 50 feet radius, and up
gradients of 1:10.

In England, with our depressed trade and agriculture, there is a great
want in many parts of the country of a cheap means of conveyance from the
railway stations into the surrounding districts; such a means of
conveyance might be afforded by light railways along or near the
road-side, the cost of which would be comparatively small, provided that
the expensive methods of construction, of signaling, and of working which
have been required for main lines, and which are perfectly unnecessary
for such light railways, were dispensed with.

It is certain that this question will acquire prominence as soon as a
system of local government has been adopted, in which the wants of the
several communities have full opportunity of asserting themselves, and in
which each local authority shall have power to decide on those measures
which are essential to the development of the resources of its own
district, without interference from a centralized bureaucracy.

       *       *       *       *       *




ON THE THEORY OF THE ELECTRO-MAGNETIC TELEPHONE TRANSMITTER.

By E. MERCADIER.

[Footnote: Note presented to the Academy of Sciences, Oct. 19, 1885.]


The first point to be studied in this theory is the _role_ performed by
the iron or steel diaphragm of the telephone, both as regards the nature
of the movements that it effects through elasticity and the conversion of
mechanical into magnetic energy as a result of its motions.

I. When we produce simple or complex vibratory motions in the air in
front of the diaphragm, like those that result from articulate speech,
either the fundamental and harmonic sounds of the diaphragm are not
produced, or else they play but a secondary _role_.

(1.) In fact, diaphragms are never set in vibration, as is supposed, when
we desire to determine the series of harmonics and nodal lines, since we
do not leave them to themselves until they have been set in motion, and
we do not allow a free play to the action of elastic forces; in a word,
the vibrations that they are capable of effecting are constantly _forced_
ones.

(2.) When a disk is set into a groove, and its edges are fixed, theory
indicates that the first harmonics of the free disk should only rise a
little. Let us take steel disks 4 inches in diameter and but 0.08 inch in
thickness, and of which the fundamental sound in a free state is about
_ut_{5}_, and which the setting only further increases. It is impossible
to see how this fundamental and the harmonics can be set in play when a
continuous series of sounds or accords below _ut_{5}_, are produced
before the disk; and yet these sounds are produced perfectly (with feeble
intensity, it is true, in an ordinary telephone) with their pitch and
quality. They produce, then, in the transmitting diaphragm other motions
than those of the fundamental sound and of its peculiar harmonics.

(3.) It is true that in practice the edges of the telephone diaphragm are
in nowise fixed, but merely set into a groove, or rather clamped between
wooden or metallic rings, whose mass is comparable to their own; and they
are, therefore, as regards elasticity, in an ill ascertained state. Yet a
diaphragm of the usual diameter (from 2 to 4 inches), and very thin (from
0.001 to 0.02 inch), clamped in this way by its edges, is capable of
vibrating when a continuous series of sounds are produced near it, by
means, for example, of a series of organ pipes. But the series of sounds
that it clearly re-enforces, in exhibiting a kind of complex nodal lines,
is plainly _discontinuous_; and how, therefore, would the existence of
such series suffice to explain the production of a _continuous_ scale of
isolated or superposed sounds, the chief property of the telephone?

(4.) The interposition of a plate of any substance whatever between the
diaphragm and the source of the vibratory motions in nowise alters the
telephonic qualities of the diaphragm, and consequently the _nature_ of
the motions that it effects--a fact that would be very astonishing if the
motions were those that corresponded to the peculiar sounds of the
diaphragm. This fact is already known, and I have verified it with mica,
glass, zinc, copper, cork, wood, paper, cotton, a feather, soft wax,
sand, and water, even in taking thicknesses of from 5 to 8 inches of
these substances.

(5.) We can put a diaphragm manifestly out of condition to effect its
peculiar scale of harmonics by placing small, unequal, and irregularly
distributed bodies upon its surface, by cutting it out in the form of a
wheel, and by punching a sufficient number of holes in it to reduce it
half in bulk. None of these modifications removes its telephonic
qualities.

(6.) We can go still further, and employ diaphragms of scarcely any
stiffness and elasticity without altering their essential telephonic
properties, the reproduction of a continuous series of sounds, accords,
and timbres. Such is the case with a sheet iron diaphragm. It is very
difficult, then, to imagine a fundamental sound and its harmonics.

The conclusion from all this appears to me to be that the mechanism by
virtue of which telephone diaphragms perform their motions is at least
analogous to, if not identical with, that through which solid bodies of
any form whatever (a wall, for example) transmit to all of their surfaces
all the simple or complex successive or simultaneous vibratory motions,
of periods varying in a continuous or discontinuous manner, that are
produced in the air in contact with the other surface. In a word, we have
here a phenomenon of _resonance_. In diaphragms of sufficient thickness
this kind of motion would exist alone. In thin diaphragms the motions
that correspond to their special sounds might become superposed upon the
preceding, and this would be prejudicial rather than useful, since, in
such a case, if there resulted a re-enforcement of the effects produced,
it would be at the expense of the reproduction of the timbre, the
harmonics of the diaphragm being capable of coinciding only through the
merest accident with those of the sounds that were setting in play the
fundamental sound of the diaphragm. This is what experiment clearly
demonstrates.

II. Let us now pass to the _magnetic role_ of the telephone diaphragm.
Such _role_ can be clearly enough defined by the following facts:

(1.) The presence of the magnetic field of the telephone in nowise
changes the preceding conclusions.

(2.) Upon farther and farther diminishing the stiffness and elasticity of
the diaphragm, I have succeeded in suppressing it entirely. In fact, it
is only necessary to substitute for it, in any telephone whatever, a few
grains of iron filings, thrown upon the pole of the magnet, covered with
a bit of paper or cardboard, in order to render it possible to reproduce
all sounds, and articulate speech with its characteristic quality,
although, it is true, with very feeble intensity.

(3.) In order to increase the intensity of the effect produced, it
suffices to substitute for the iron diaphragm a thin disk of any sort of
slightly flexible substance, metallic or otherwise, cardboard, for
example, and through the aperture of the usual cover of the instrument to
scatter over it from 1½ to 3 grains of iron filings. In this way we
obtain an iron filings telephone. By properly increasing the intensity of
the magnetic field, I have been able to form telephones of this kind that
produced in an ordinary receiver as intense effects as those given by
the usual transmitters with stiff disks, and which, too, were reversible.
But for a field of given intensity, there is a weight of iron filings
that produces a maximum of effect.

We thus see that the advantage of the iron diaphragm over filings is
truly reduced to the presentation of a much larger number of magnetic
molecules to the action of the field and to external actions, within the
same volume. It increases the _intensity_ of the telephonic effects,
although for _the production_ of the latter with all their variety,
fineness, and perfection it is nowise indispensable. It suffices, after a
manner, to materialize the lines of force with iron filings, and to act
mechanically upon them, and consequently upon the field itself.

       *       *       *       *       *




ON THE THEORY OF THE RECEIVER OF THE ELECTRO-MAGNETIC TELEPHONE.

By E. MERCADIER.

[Footnote: Note presented to the Academy of Sciences, November 16, 1885.]


On a former occasion I described some experiments that had led me to a
theory of the telephone transmitter; a few words will suffice to expose
that of the receiver.

Such theory gave rise during the first years succeeding the invention of
the telephone to a considerable number of investigations, the principal
results of which may be summed up in the two following points:

1. All the parts of a telephone receiver--core, helix, disk, handle,
etc.--vibrate simultaneously (Boudet, Laborde, Breguet, Ader, Du Moncel,
and others). But there is no doubt that by far the most energetic effects
are those of the disk. It has been possible to put the vibrations of the
core and helix beyond a doubt only by employing very energetic
transmitter currents, or very simplified and special arrangements of the
receiver (Ader, Du Moncel, and others).

2. In telephone receivers we may employ disks or diaphragms of any
thickness up to six inches (Bell, Breguet, and others).

From the first point it had already resulted that the diaphragm was no
more indispensable in the receiver than it was in the transmitter, as I
have already shown (_Comptes Rendus_, t. ci., p. 944); and, from the
second point, that there were other effects in a receiver than those that
could result from the transverse vibrations corresponding to the
fundamental sound and to the harmonics of the diaphragm.

So Du Moncel, basing a theory upon these two categories of facts,
asserted that the effects of the telephone receiver were principally due
to the molecular vibrations of the core of the electro-magnet (analogous
to those that had been studied by Page, De la Rive, Wetheim, Reis, and
others), super-excited and re-enforced by the iron diaphragm operating as
an armature.

This theory has certainly truth for a basis; but it is incomplete, in
that the molecular vibrations of the core are but a very feeble accessory
phenomenon, and not a prominent one. At all events, I believe that we
can, in a few words, and very simply, present the theory of the telephone
receiver by going back to the facts that served me as a basis for the
theory of the transmitter, and that result from studies made with
telephones of ordinary forms.

In fact, it is enough to remark that the iron filings telephone
transmitter described in a preceding article (_1. c_.) is reversible and
capable of serving as a receiver--not a very intense one, it is true, but
here it is a question of the _nature_ of the phenomena, and not of their
intensity. It at once results that in receivers, as in transmitters, the
rigidity of the iron diaphragm is in nowise indispensable for telephonic
effects, such as the production of continuous series of successive or
simultaneous sounds and of articulate speech.

The diaphragm serves but to increase the intensity of these effects, as
in the transmitter, by concentrating the lines of force of the field, and
by presenting a greater surface to the air--the necessary vehicle of
sound. When it is thick, the internal motions that it takes on in
consequence of variations in the field, and which are transmitted to the
surrounding air and the ear, are solely those of resonance. When it is
very thin, the peculiar motions resulting from its geometric form and its
structure may become superposed upon the preceding, because it may then
happen that the corresponding sounds remain within the limits of the
pitch wherein the human voice usually moves (from ut_{2} to ut_{5});
but then, also, as the harmonics of the voice in nowise coincide with the
proper sounds of the diaphragm, the intensity of the effects is obtained
at the expense of a good reproduction of the timbre. This is certainly
one of the causes of the nasal timbre of most thin-diaphragmed
telephones. By diminishing their thickness, we lose in quality what we
gain in intensity.

But even in this latter respect there is a maximum for receivers, as I
have already pointed out that there is for iron filings transmitters. For
a magnetic field of given intensity, there is, all things equal, a
diaphragm thickness that gives a maximum telephonic result. Such result,
which is analogous to those that occur in other electro-magnetic
phenomena, may explain the want of success of many tentatives made
somewhat at haphazard, with a view to increasing the intensity of
telephonic effects.

       *       *       *       *       *




DECOMPOSITION AND FERMENTATION OF MILK.


Dr. F. Hueppe, who has paid great attention to this subject, describes
five distinct organisms which he finds to be invariable accompaniments of
lactic fermentation. One of these he isolated on nutrient gelatine in the
form of white, shining, flat, minute beads. This organism has the power
of transforming milk sugar and other saccharoses into lactic acid, with
evolution of carbonic acid gas. It is rarely found in the saliva or
mucilage of the teeth. In these are two micrococci, both of which cause
the production of lactic acid, but which manifest differences in their
development under cultivation. There are also two pigment forming
bacteria, _Micrococcus prodigiosus,_ which produces intensely red spots,
and the yellow micrococcus of osteomyelitis. These five bacteria are so
different and so constant in their properties that they must, in Dr.
Hueppe's opinion, be regarded as distinct species. In addition to them
there is in milk an organism resembling _Mycoderma aceti_, which
transforms milk sugar into gluconic acid.

       *       *       *       *       *




THE NEW "BURGTHEATER" IN VIENNA.


At last the new "Burgtheater" in Vienna is completed. We say "at last,"
for work was begun on this new theater more than ten years ago. One after
another, monumental architectural works have been erected, which are no
less grand and beautiful than this. They were finished long ago, and
given over to their respective uses--the Parliament buildings, the
"Rathhaus," the University; but Baron Hasenauer, who had charge of the
construction of this building, as well as of many others, could not bring
himself to the quicker _tempo_ of Messrs Hansen, Schmid, and Ferstel. The
citizens of Vienna were naturally impatient to see their beautiful
"Ringstrasse" completed, and only the Hasenauer buildings were needed to
make it perfect.

[Illustration: THE NEW IMPERIAL PALACE THEATRE, VIENNA. ORIGINAL
DESIGN BY J.J. KIRCHNER.]

The building was built according to the plans of Semper and Hasenauer;
for, as in the other great buildings erected by Hasenauer, the new palace
and the museums, Semper's plans served as a foundation. All the modern
improvements in the architecture of theaters have been embodied in the
new theater, for the terrible catastrophe at the Ringtheater taught a
lesson which has not been forgotten, and the greatest care has been taken
to guard against fire.

The new "Burgtheater" stands directly opposite the imposing "Rathhaus"
(senate-house), and is separated from the same by a charming park; to
the right stands the University, and to the left the Houses of
Parliament. In order to be worthy of such company, and not be
overshadowed by these buildings, it was necessary that the theater should
be very grand. The most important requirements have been perfectly
fulfilled; beauty, elegance, appropriateness, and security against fire,
nothing has been neglected.

The principal part of the building stands out strongly, and is flanked on
either side by a pavilion-like wing. The audience room will accommodate
about two thousand people.

The public and the actors alike rejoice in the new Burgtheater, for which
they have waited so long.

       *       *       *       *       *




THE NEW GERMAN BOOKDEALERS' EXCHANGE IN LEIPZIG.


It seems strange that book-printing and the book trade in general should
have developed so slowly in the busy city of Leipzig, where a university
was established as early as the beginning of the fifteenth century. The
first honorable mention of the printing of Leipzig was made during the
first decade of the sixteenth century, but it was not until the end of
the seventeenth century that the printing and publishing of books
received a notable impulse, which was given it by Messrs. J.F. Gleditsch
and Thomas Fritsche and Profs. Carpzov and Mericke, who published many
works of great typographical beauty.

From 1682 to 1700 ninety-one papers and periodicals appeared in Leipzig,
of which the _Acta eruditorum_ was the oldest, being the first German
scientific paper. At this time there were seventeen printing
establishments in Leipzig, and the seventy presses in use printed, on an
average, 2,000 bales of paper yearly.

One of the leading bookdealers, Philipp Emanuel Reich, won the
approbation of his fellow citizens by establishing the first Bookdealers'
Association at the time of the Easter Fair in Leipzig, in 1764, and it
was through his efforts that the Book Exchange or Fair was founded, which
has placed Leipzig at the head of the book trade; but several years
passed before this private undertaking become a public association. About
1834 a building was erected specially for a book exchange or bourse, but
this building was soon outgrown, and it was decided to build a new one
which should be adequate to the requirements of the institution.

A competition for designs for the new building was opened, and five
designs were presented, from which the plan of Messrs. Kayser and Von.
Grossheim, of Berlin, was selected. This design, which is shown in the
accompanying cut, taken from the _Illustrirte Zeitung,_ presents a
picturesque grouping of the different parts of the building, the main
building being on one street and the adjoining building on another
street. The roof, which forms a beautiful sky-line, is ornamented with
dormer-windows and little towers, there being a large tower on the main
building.

[Illustration: PRIZE PLAN FOR THE NEW BOOK EXCHANGE IN LEIPZIG, BY
MESSRS. KAYSER AND VON GROSSHEIM, ARCHITECTS.]

To the left of the principal hall in the main building, which has three
large ornamental windows, there is a little hall, the central office, and
committee rooms, while the restaurant and the assembly rooms are on the
right. In the smaller building, through which there is a central
corridor, are the order rooms, assorting rooms, editorial sanctum of the
_Borsenblat_ (Bourse journal), and the post office, with telegraph
offices.

A low building runs almost the entire length of the main building, to
which it is joined at the right and left by side wings, thus inclosing an
open court. In this low building the exhibition rooms are arranged, and
in the middle is a vestibule through which these exhibition rooms, the
wardrobes, and the great hall can be reached. Over the vestibule is a
cupola.

The arrangements for lighting, heating, and ventilation are excellent.
Steam heat is used, and the large hall is ventilated by the pulsation
system.

The building, which is of red brick and sandstone, is worthy of holding a
place among the numerous beautiful buildings which have been erected in
Leipzig during the last few years. The cost of the building was limited
to 700,000 M., or about $160,000.

       *       *       *       *       *




A correspondent has transmitted to the editor of _L'Union Pharmaceutique_
the prospectus of an oyster dealer who, besides dealing in the ordinary
bivalves, advertises specialties in medicinal oysters, such as "huitres
ferrugineuses" and "huitres au goudron." The "huitres ferrugineuses" are
recommended to anæmic persons, and the "huitres au goudron" are said to
replace with advantage all other means of administering tar, while of
both it is alleged that analyses made by "distinguished _savants_" leave
no doubt as to their valuable qualities.

       *       *       *       *       *




ALIZARINE DYES.


Notwithstanding the unprecedented progress of the coal-tar dyestuff
industry during the past few decades, the time-honored indigo, logwood,
fustic, etc., have been only partly displaced by the coal-tar products in
wool dyeing. The cause is that, though the dyer handled many aniline
dyestuffs which dyed as fast against light as logwood or fustic, the dye
proved unsatisfactory for fulling goods, because it bled in the treatment
with soap and soda, and often more or less changed its tone. We intend to
render a service to our readers by calling their special attention to
some products of the coal-tar industry which are free from these defects
of aniline dyestuffs, and for which it is claimed that they far surpass
logwood, fustic, cudbear, etc., as to fastness against light, and
excellently stand fulling. We allude to the alizarine dyestuffs, which
have long since been introduced and are largely employed in cotton dyeing
and printing.

Alizarine, which has been extensively discussed in various articles in
our journal, is the coloring matter contained in the madder root. In
1869, two German chemists, Graebe and Liebermann, succeeded in
artificially producing this dyestuff from anthracene, a component of
coal-tar. The artificial dyestuff being perfectly pure and free from
those contaminations which render the use of madder difficult, it soon
was preferred to the latter, which it has at present nearly completely
displaced.

The discovery of alizarine red was soon followed by those of alizarine
orange, galleine, coeruleine, and, in 1878, of alizarine blue.

The slow adoption of these dyestuffs in the wool-dyeing industry is
principally attributable to the deep-rooted distrust of wool dyers
against any innovation. This resistance, however, is speedily
disappearing, as every manufacturer and dyer trying the new dyestuffs
invariably finds that they are in no respect inferior to his fastest dyes
produced with indigo and madder, but are simpler to apply and more
advantageous for wool.

The alizarine colors are dyed after an old method which is known to every
wool dyer. The wool is first boiled for 1½ hours with chromate of potash
and tartar, then dyed upon a fresh bath by 2½ to 3 hours' boiling. All
alizarine colors (such as those of the Badische Anilin und Soda Fabrik,
of Ludwigshafen and Stuttgart; Wm. Pickhardt & Kuttroff, New York,
Boston, and Philadelphia, viz.):

    Alizarine orange W, for brown orange,
    Alizarine red WR, for yellow touch ponceau or scarlet,
    Alizarine red WB, for blue touch yellow or scarlet,
    Alizarine blue WX and SW, for bright blue,
    Alizarine blue WR SRW, for dark reddish blue,
    Coeruleine W and SW, for green, and
    Galleine W, for dahlia,

are dyed after the same method, which offers the great advantage that all
these colors can be dyed upon one bath, and that by their mixture
numerous fast colors can be produced. On the ground of numerous careful
experiments, the writer recommends the following method, which gives well
developed and well fixed colors, viz.:

For 100 kil.--The scoured and washed wool is mordanted by boiling for 1½
hours in a bath containing 3 kil. chromate of potash and 2½ kil. tartar,
and lightly rinsed; when it can immediately be dyed. For 1,000 lit.
water, 1 lit. acetic acid of about 7° Be. is added to the bath. If the
water is very hard, double the quantity of acetic acid, which is
indispensable, is added. Then the required quantity of dyestuff is added,
well stirred, the wool entered, and the temperature raised to boiling,
which is continued for 2½ to 3 hours, that is, until a sample taken does
no longer surrender any color to a hot solution of soap. Loose wool and
worsted slubbing can be entered at 60° C. (140° F.). In dyeing yarn and
piece-goods, however, it is advisable to enter the bath cold, work for
about 1/4 hour in the cold, and then slowly to raise the temperature in
about one hour to the boiling point. With this precaution, level and
thoroughly dyed goods are always obtained. If the wool is entered in a
hot bath, or if it is rapidly brought to a boil, the dyestuff is too
rapidly fixed by the mordant and is liable to run up unevenly, and, with
piece-goods, more superficially. For the same reason the goods must
always be well wetted out before entering the bath.

We add some special recipes for the various colors, the mordant for all
of them being of 3 per cent. chromate of potash and 2½ per cent. tartar
for 100 by weight of dry wool.

1. _Orange, Brown Touch_.
20 kil. wool, mordant with 600 grm. chromate of potash and 500 grm.
tartar, dye with 3 kil. alizarine orange W.

2. _Ponceau, Yellow Touch_.

20 kil. wool, mordant as for No. 1, dye with 2 kil. alizarine red WR 20
per cent.

3. _Ponceau, Blue Touch_.

20 kil. wool, mordant like No. 1, dye with 2 kil. alizarine red WB 20 per
cent.

4. _Dahlia_.

20 kil. wool, mordant like No. 1, dye with 5 kil. galleine W.

5. _Green_.

20 kil. wool, mordant like No. 1, dye with 6 kil. coeruleine W.

_For Piece-goods._

20 kil cloth, mordant the same, dye with 1 kil. 200 grm. coeruleine SW.

6. _Blue, Bright_.

20 kil. wool, mordant the same, dye with 6 kil. alizarine blue WX.

_For Piece-goods._

20 kil. cloth, mordant the same, dye with 1 kil. 200 grm. alizarine blue
SW.

7. _Blue, Dark and Red Touch_.

20 kil. wool, mordant like No. 1, dye with 6 kil. alizarine blue WR.

_For Piece-goods._

20 kil. cloth, mordant the same, dye with 1 kil. 200 grm. alizarine blue
SRW.

Particular stress is to be laid upon the great fastness of the alizarine
dyes against light and fulling. Besides, these dyestuffs contain nothing
whatever injurious to the wool fiber. Sanders, which very much tenders
the wool, as every dyer knows, can in all cases be replaced by alizarine
red and alizarine orange, making an end to the spinners' frequent
complaints about too much waste.

Alizarine blue in particular seems to be destined to replace indigo in
the majority of its applications, having at least the same power of
resisting light and acids, and relieving the dyer of the troublesome,
protracted rinsings required for indigo dyed goods. Every piece-dyer
knows that the medium and dark indigo blue goods still rub off, even
after eight hours' rinsing; but alizarine blue pieces are perfectly dyed
through and clean after one hour of rinsing. Another advantage of
alizarine blue and the other alizarine dyestuffs is that they unite with
all wood colors, as well as with indigo carmine and all aniline
dyestuffs. A fine and cheap dark blue, for instance, is obtained by
mordanting the wool as above stated and dyeing (20 kil.) in the second
bath with 6 kil. alizarine WX and 2 kil. logwood chips; the wood is added
to the bath together with the alizarine blue WX, and the best method is
to put it into a bag which is hung in the bath.--_D. Woll.-Gew.; Tex.
Colorist._

       *       *       *       *       *




Papier maché has come of late to be largely used in the manufacture of
theatrical properties, and nearly all the magnificent vases, the handsome
plaques, the graceful statues, and the superb gold and silver plate seen
to-day on the stage are made of that material.

       *       *       *       *       *




CEMENT PAVING.


The streets of "Old London" at the recent Inventions Exhibition at South
Kensington were paved with a material in imitation of old, worn bowlder
stones and red, herring-boned brickwork, all in one piece from one side
of the street to the other. The composition is made by Wilkes' Metallic
Flooring Company, out of a mixture consisting chiefly of iron slag and
Portland cement, a compound possessing properties which won the only gold
medal given for paving at that Exhibition. At the present time the
colonnade in Pall Mall, near Her Majesty's Theater, is being laid with
this paving, which is also being extensively used in London and the
provinces for roads, tramways, and flooring; the composition is likewise
sometimes cast into artistic forms for the ornamentation of buildings, or
into slabs for roofing, facing, and other purposes. The subway from the
Exhibition to the District Railway is laid with the same material.

The works of the Wilkes Metallic Flooring Company are in the goods yard
of the Midland Railway Company at West Kensington. The Portland cement,
before it is accepted at the works, is tested by means of an Aidie's
machine. The general strain the set cement is required to bear is 750 lb.
to the square inch. All samples which will not bear a strain of 500 lb.
are rejected. The various iron slags are carefully selected, and rejected
when too soft, and at the works a small percentage of black slag, rich in
iron, is mixed in with them. The lumps of slag are first crushed in a
Mason & Co.'s stone breaker, and then sifted through 1/8 in., 1/4 in.,
and 1/16 in. wire meshes into these three sizes for mixing. Next the
granulated substance is thoroughly well washed with water to remove
soluble matter and impalpable dust, and afterward placed where it is
protected from the access of dust and dirt. The washing waters carry off
some sulphides, as well as mechanical impurities. The Portland cement is
not used just as it, comes from the works, but is exposed to the air in a
drying room for about fourteen days, and turned over two or three times
during that period. The slag is also turned over three times dry and
three times wet, and mixed with the Portland cement by means of water
containing 5 per cent. of "Reekie" cement to make the whole mass set
quickly. The mixture is then turned over twice and put into moulds; each
mould is first half filled, and the mixture then hammered down with iron
beaters. The rest of the composition is then poured in, beaten down, and
the whole mould violently jolted by machinery to shake down the mixture
and to get rid of air holes. While it is still wet the casting is taken
out of the mould, its edges are cleaned, and after the lapse of one day
it is placed in a bath, of silicate of soda. Should the casting be
allowed to get dry before it is placed in this bath, no good results
would be obtained; it is left in the bath for seven days. When delicate
stone carvings have to be copied, the moulds are of a compound of
gelatine, from the flexible nature of which material designs much
undercut can be reproduced. For the foregoing particulars we are indebted
to Mr. William Millar, the working manager at West Kensington. Sometimes
the composition is cast in large, heavy slabs, moulded on the top to
resemble the surface of roads of granite blocks. A feature of the
invention is the rapidity with which the composition sets. For instance,
the manager states that a roadway was finished at the Inventions
Exhibition at seven o'clock one night, and at six o'clock next morning
four or five tons of paper in vans passed over it into the building,
without doing any harm to the new road. In laying down roads, much of the
preparation of the material is done on the spot, and the composition
after being put down unsilicated in a large layer has the required design
stamped upon its wet surface by means of wooden or gutta-percha moulds.
As regards the durability of the composition, Mr. T. Grover, one of the
directors, says that the company guarantees its paving work for ten
years, and that the paving, the whole of the ornamental tracings, and
some of the other work at Upton Church, Forest Gate, Essex, were executed
by means of Wilkes' metallic cement three years ago, and will now bear
examination as to its resistance to the action of weather. Some of this
paving has been down in Oxford Street, London, for more than six years.
Mr. A.R. Robinson, C.E., London agent of the company, states that the
North Metropolitan Tramway Company has about 25,000 yards of it in use at
the present time, and that the paving is largely used by the War Office
for cavalry stables. The latter is a good test, for paving for stables
must be non-slippery and have good power of resisting chemical action.

In the Wm. Millar and Christian Fair Nichols patent for "Improvements in
the means of accelerating the setting and hardening of cements," they
take advantage of the hydraulicity of certain of the salts of magnesia,
by which the cements set hard and quickly while wet. For accelerating the
setting of cements they use carbonate of soda, alum, and carbonate of
ammonia; for indurating or increasing the hardening properties of cements
they use chloride of calcium, oxide of magnesia, and chloride of magnesia
or bittern water; for obtaining an intense hardness they use oxychloride
of magnesia. The inventors do not bind themselves to any fixed
proportions, but give the following as the best within their knowledge.
For colored concretes for casts or other purposes they use Carbonate of
soda, 8.41; carbonate of ammonia, 1.12; chloride of magnesia, 0.28;
borax, 0.56; water, 89.63; total, 100.00. For gray concrete for any
purpose they use: Alum, 8.46; caustic soda, 0.28; whitening or chalk,
0.56; borax, 0.56; water, 90.14; total, 100.00. For floors or slabs _in
situ_ they add to cement, well mixed and incorporated with any required
proportion of agglomerate for a base, liquid composition of the following
proportions: Oxide of magnesia, 0.29; chloride of magnesia, 0.29;
carbonate of soda or alum, 4.74; water, 94.68; total, 100.00. Articles
manufactured by the invention are afterward wetted with chloride of
calcium and placed in a bath containing a solution of silicate of soda or
chloride of calcium. The strength of the chloride of calcium is equal to
about 20 deg. specific gravity.

C.A. Wilkes and William Millar's improved "metallic compound for
flooring, paving, and other purposes," has for its object to provide a
paving compound which is not slippery or liable to soften in hot weather,
which sets rapidly, and is durable. To three parts of blast furnace slag
are added one part of hydraulic cement and enough water to give the
proper consistency. To each gallon of water used is added one part of
bittern water--the dregs from the manufacture of sea salt--or one part
of brine, or about 5 per cent. of carbonate of soda, and 2½ per cent. of
carbonate of ammonia. In the compound they sometimes use potash in the
proportion of about 5 per cent. of the carbonate of ammonia and carbonate
of soda, and when potash is used with bittern water or brine, the
proportion of the latter is correspondingly reduced. The compound is of a
blue gray color; but when a more striking color is desired, red or yellow
oxide of iron may be added. When more speedy induration is necessary,
they add about 1 oz. of copperas to every gallon of compound used. The
claim is the admixture of bittern water, carbonate of soda, and carbonate
of ammonia with the washed slag and cement.

Another improvement, by C.A. Wilkes, relates, in laying _in situ_ any
metallic or other materials for street roadways, to completing the
convenience thereof by roughening or grooving the surfaces. The concrete
is laid in a plastic condition upon a bed of hard core, broken stone, or
preferably rough concrete. For footpaths the material may be laid in
convenient sections, say 4 ft. to 8 ft. square and 2 in. to 4 in. thick;
and in order to allow for the expansion of the material during the
setting of the sections or subsequent variations in temperature, he packs
the joints between the sections with a layer of felting cloth or other
compressible material, thus forming expansion joints. Sometimes he
slightly roughens the surface of the material, to give better foothold to
pedestrians. Sometimes the grooving is made in imitation of ordinary
granite paving sets. In tramway pavement there are grooves to give a grip
to the horses' feet, and a slight camber between the rails. He states
that a great advantage in laying a pavement by the method is that, when
any repairs are necessary, a piece of the exact size can be manufactured
at the works, and stamped to the same pattern as the adjoining pavement,
then placed at once in position on the removal of the worn portion, thus
saving the time necessary for the setting of the concrete on the
spot.--_The Engineer_.

       *       *       *       *       *




A NEW BLEACHING PROCESS.


In the spring of 1883 a Mr. J.B. Thompson, of New Cross, London, patented
a new process of bleaching, the main feature of which consisted in the
use of carbonic acid gas in a closed vessel to decompose the chloride of
lime. The "chemicking" and "souring" operations he performed at one and
the same time. The reactions which took place in his bleaching keir were
stated by the inventor as follows:

      Cl.\
1.  Ca    ) + CO_{2} = CaCO_{3} + Cl_{2}.
     OCl./

2. OH_{2} + Cl_{2} = (ClH)_{2} + O.

3. CaCO_{3} + (ClH)_{2} = CaCl_{2} + CO_{2} + H_{2}O.

That is, in 1 chloride of lime and carbonic acid react upon each other,
producing chalk and nascent chlorine; in 2 the nascent chlorine reacts
upon the water of the solution and decomposes it, producing hydrochloric
acid and nascent oxygen, which bleaches; in 3 the hydrochloric acid just
formed reacts upon chalk formed in 1, and produces calcium chloride and
one equivalent of water, and at the same time frees the carbonic acid to
be used again in the process of decomposing the chloride of lime.

When the process was first brought to the notice of the Lancashire
bleachers, it met with an amount of opposition. Some bleaching chemists
declared the process was not patentable, as fully half a century ago
carbonic acid was known to decompose chloride of lime. The patentee's
answer was emphatic, that carbonic acid gas had never been applied in
bleaching before. After some delay one of the largest English cotton
bleachers, Messrs. Ainsworth, Son & Co., Halliwell, Bolton, threw open
their works for a fair test of the Thompson process on a commercial
scale.

The result of trial was so satisfactory that a company was formed to work
the patent. Soon after this the well-known authorities on the oxidation
of cellulose, Messrs. Cross & Bevan and Mr. Mather, the principal partner
in the engineering firm of Mather & Platt, of Salford, Lancashire, joined
the company. For the last twelve months these gentlemen have devoted
considerable attention to improving the original contrivance of Thompson,
and a few weeks since they handed over to Messrs. Ainsworth the machinery
and instructions for what they considered the most complete and best
process of bleaching that has ever been introduced.

Recently a "demonstration" of the "Mather-Thompson" process of bleaching
took place at Halliwell, and to which were invited numerous chemists and
practical bleachers. Having been favored with an invitation, I propose to
lay before your readers a concise report of the proceedings.

It is usual in this country to give a short preliminary boil to the cloth
before it is brought in contact with the alkali, the object being to well
scour the cloth from the loose impurities present in the raw fiber and
also the added sizing materials. In the new process the waste or spent
alkaline liquors of the succeeding process are employed, with the result
that the bleaching proper is much facilitated. The economy effected by
this change is considerable, but in the next operation, that of
saponification, the new process differs even more widely from those
generally in use. In England, "market" or "white" bleaching requires a
number of operations. There is first the alkaline treatment divided into
the two stages or processes of lime stewing and bowking in soda-ash,
which only imperfectly breaks down the motes. There is consequently a
second round given to the goods, consisting of a bowk in soda-ash,
followed by the second and usually final chemicking. There is, therefore,
much handling of the cloth, with the consequent increase of time and
therefore expense.

Now, in the saponification process, the Mather-Thompson Company claim to
have achieved a complete triumph. They use a "steamer keir," the
invention of Mr. Mather. This keir is so constructed that it will allow
of two wire wagons being run in and the door securely fastened. At the
top of the keir is fixed a mechanical appliance for steaming the cloth.
The steamer keir process consists essentially in:

1. The application of the alkali in solution and in its most effective
form, viz., as caustic alkali, to each portion of fiber in such quantity
as to produce the complete result upon that portion.

2. The immediate and sustained action of heat in the most effective form
of steam.

Before the cloth is run into the steamer keir on the wire wagons, it is
saturated with about twice its weight of a dilute solution of caustic
soda (2° to 4° Twaddell = 0.5 to 1% Na_{2}O) at a boiling-temperature,
when in the steamer keir it is exposed to an atmosphere of steam at four
pounds pressure for five hours. This part of the process is entirely new.
The advantage of using caustic soda alone in the one operation, such as I
describe, has been long recognized, but hitherto no one has been able to
effect this improvement. It will be observed that the Mather-Thompson
process does away entirely with the use of lime and soda-ash in at least
two boilings and the accessory souring operation. In the space of the
five hours necessary for the steamer keir process the goods are
thoroughly bottomed and all the motes removed, no matter what be the
texture or weight of the cloth. After the cloth is washed in hot water it
is removed from the steamer keir, then follows a rinse in cold water, and
the goods are ready for the bleaching process.

In passing to the bleaching and whitening process, it may be necessary to
say that thus far the original Thompson process has been entirely
altered. Now we come to that part of the bleaching operation where the
essential feature in Thompson's patent is utilized. The patentee has
apparently thoroughly grasped the fact that carbonic acid has great
affinity for lime and that it liberates, in its gaseous condition, the
hypochlorous acid, which bleaches. The most perfect contact is realized
between the _nascent_ hypochlorous acid resulting from its action and the
fiber constituent in the exposure of the cloth treated with the bleaching
solution to the action of the gas. The order of treatment is as follows:

    (1) Saturation with weak chemic (1° Tw.), squeeze,
        and passage to gas chamber.
    (2) Wash (running).
    (3) Soda scald.
    (4) Wash.
    (5) Repetition of 1, but with weaker chemic (½° Tw.).
    (6) Wash.
    (7) Scouring.

The whole of the above operations are carried out on a continuous plan,
the machinery being the invention of Mr. Mather. The cloth travels along
at the rate of sixty or eighty yards a minute, and comes out a splendid
white bleach. The company consider, however, that it is necessary in the
case of some cloth to give a second treatment with chemic and gas, each
of thirty seconds duration, with an intermediate scald in a boiling very
dilute alkaline solution. Mr. Thompson originally claimed that the use of
carbonic acid gas rendered the employment of a mineral acid for souring
unnecessary. It is considered now to be advisable to employ it, and the
souring is included, as will be observed, in the continuous operation.

The new process for treating cloth differs materially from that
originally proposed by Mr. Thompson. His plan was to use an air-tight
keir in conjunction with a gas-holder. It is obvious that the
"continuous" process would not answer for yarns; Thompson's keir is,
therefore, employed for these and all heavy piece-goods.

Thus far I have given a concise outline of the Mather-Thompson process of
bleaching, which, it cannot be denied, differs materially from any system
hitherto recommended to the trade. Beyond doubt the goods are as
perfectly bleached by this process as by any now in use. The question
arises, What pecuniary advantage does it offer? Mr. Manby, the manager of
Messrs. Ainsworth, has informed me that he has bleached as much as ten
miles of cloth by the new process, and is, therefore, entitled to be
heard on the subject of cost. In regard to the consumption of chemicals,
he estimates the saving to amount to (in money value) one-fourth; steam
(coal), one-half; labor, one-half; water, four-fifths; time, two-thirds.

It might be well to contrast the process formerly employed by Messrs.
Ainsworth with that they have recently adopted:

                 "MATHER-THOMPSON" SYSTEM.

Alkali.                  Bleach                Acid Machine
                        (chemic).                 Washes.
       / Saturate.
  (1) <
       \ Steam.
                  / (2) Continuous
                 |       (chemic)
                 |       machine
                 |       (or keir if
             (2) <       for yarns,
                 |       etc.).
                 |        (2a) Machine or
                  \            pit sour.
                                           (3) Wash up for
                                                finishing.

                      ORDINARY SYSTEM.

Alkali.                  Bleach.               Acid Machine
                                                  Washes.

(1) Lime stew.                                    (1) Wash.
                          (2) Sour.               (2)  "
(3) Gray bowk                                     (3)  "
     (soda ash).
       (4)I Chemic.                               (4)  "
                          (5) Sour.               (5)  "
(6) White bowk.                                   (6)  "
     (7)II Chemic.                                (7)  "
                          (8) Sour.               (8)  "

It will be understood that 2 and 2a are merged into a single process by
using the "continuous" machine. Of course, it will be understood that the
cloth has in each case to be cleansed from size and loose impurities. The
"Mather-Thompson" Company claim that their system takes twelve hours in
the case of "market" or "white" bleaching. They reckon eight hours for
the steaming process and four for bleaching and washing. This has to be
compared with the old system, which generally takes forty hours, made up
as follows: 8 treatments with reagents and the necessary washings, the
former taking four hours and the latter one hour each.

The "Mather-Thompson" system has created considerable commotion in
English bleaching circles. It is generally considered that the bleachers
throughout the whole country will be compelled to adopt it, so great is
the saving in time and cost. In commencing a bleachery, the cost of
plant by this system is, I understand, less than by the old
processes.--_Textile Colorist_.

       *       *       *       *       *




INSTRUMENTS FOR DRAWING CURVES.

By Prof. C.W. MacCord, Sc.D.

I. THE HYPERBOLA.


We are free to express the opinion at the outset, that for various
reasons the draughtsman is likely to gain very little advantage by the
use of mechanical devices for describing mathematical curves by
continuous motion. Such instruments are as a rule not only complicated
and expensive, but cumbersome and difficult of adjustment. It may be
suggested, _per contra_, that these objections do not apply to the
familiar combination of two pins and a string, for tracing the
"gardener's ellipse." But we question the propriety of classing a string
among strictly mechanical devices; it has its uses, to be sure, but in
respect to perfect flexibility and inextensibility it cannot be relied on
when rigid accuracy is required in drawing any of the conic sections.

[Illustration: FIG. 1.]

Nevertheless, the construction of such apparatus affords a study which to
some is fascinating, and even in the abstract is not devoid of utility.
In each case a definite object is presented, and usually a choice of
methods of attaining it; success requires a thorough knowledge of the
properties of the curve in hand, while ingenuity is stimulated, and
familiarity with expedients is cultivated, by the effort to select the
most available of those properties, and to arrange parts whose motions
shall be in accordance with them. Such exercise of the inventive
faculties, then, is good training for the mechanician. And it must not be
forgotten that a mechanical movement thus devised for one purpose very
frequently is either itself applicable to a different one, or proves to
be the germ from which are developed new movements which can be made so;
the solution of one problem sometimes furnishing a hint or clew of great
value in dealing with another.

[Illustration: FIG. 2.]

We proceed, then, to describe a few instruments of this kind, which we
believe to be new, in the hope that in the manner just pointed out they
may render a greater service than that for which they are directly
intended.

The first of these, shown in Fig. 1, is for the purpose of describing the
hyperbola. The properties of the curve, upon which the action of the
instrument depends, are illustrated in Fig. 2, where MM, NN, are the two
branches of an hyperbola; C the center; AB the major axis; F and F' the
foci. If now a tangent TT be drawn at any point as P of either branch,
and a perpendicular let fall upon it from the nearer focus F be produced
to cut at G a line drawn from P to the farther focus F', then this
perpendicular will cut the tangent at a point I upon the circumference of
a circle described about C upon AB as a diameter, and also the distance
F'G will be equal to AB.

In Fig. 1, then, we have a crank CI, whose radius is equal to CB, half
the major axis, turning about a fixed center C. Upon the crank-pin I is
hung, so as to turn freely, a rigid cross composed of a long slotted
piece TT, in which slides a block, and two cylindrical arms at right
angles to it and in line with each other, the axis EE passing through I.
The arm on the right slides through a socket pivoted at the focus F; the
one on the left slides through a similar socket, which is pivoted at G to
a third socket longer than the others, which again is pivoted at the
focus F'; the distance F'G being equal to AB. Through this long socket
slides a rod KP, the end P being formed into an eye, by which this rod is
pivoted to the block which slides in the long slot, and thus controls the
motion of the block; and the pivot at P is centrally drilled to carry the
pencil. It is thus apparent that the center line of the slot TT must in
all positions be tangent to the hyperbola PBR, which will be traced by
the pencil, whose motions are so restricted as always to satisfy the
conditions explained in connection with Fig. 2.

The apparatus as thus represented does not at first sight appear unduly
complicated. But in order to render it adjustable, so that hyperbolas of
varying eccentricities and on different scales may be drawn with it,
several parts not here shown must be added. A frame must be provided, in
which to arrange supports for the pivots at F and F', and these supports
connected by a right and left handed screw, or equivalent means of
altering the distance between the foci; the crank CI and the socket F'G
must be of variable length, and these in each case would require to be
carefully adjusted. So that, as we stated in the beginning, it is
questionable whether a draughtsman of ordinary skill could draw the curve
any more readily by the aid of such a piece of mechanism than he could
without it; but it may claim a passing notice as a novel device, and the
first one, we believe, for describing the hyperbola by a combination of
rigid parts.

       *       *       *       *       *




EXPERIMENTS WITH FIBERS.

By Dr. THOMAS TAYLOR.


As Microscopist of the United States Department of Agriculture, I am
frequently called upon to make investigations as to the character of
textile fibers and fabrics, not only for the public generally, but also
for several departments of the Government.

Textile fibers are presented both in the raw and as articles of
manufacture. In the latter case they may have been dyed, stained, or
painted. It is obvious that under these conditions the fibers should be
subjected to chemical reaction to bring them as nearly as possible to
their normal condition.

Considering how well the structures of the common textile fibers of
commerce--cotton, flax, ramie, hemp, jute, Manila hemp, silk, and
wool--have been investigated and minutely described by able and exact
microscopists, I will in this paper confine myself chiefly to such
experiments as I have personally made with textile fibers, treating them
with chemical agents while under the objective.

While I am aware that this method is not wholly new, I am satisfied that
comparatively little work has been done in this direction, and that a
wide field is still open for future research.

As microscopists, we have to fortify ourselves in every way that will
sustain, by truthful work, the value of the microscope as a means of
research, sometimes conducting our experiments under the most trying
circumstances. Fibers may be so treated by experts as to make it
difficult to determine how their changed appearance has been effected,
and it may happen in this age of experiment and of fraud that important
decisions in commercial transactions and in criminal cases may depend on
our observations.


DETECTION OF A FRAUD.

A case in point will illustrate this. While Dr. Dyrenforth was chief of
the chemical division of the U.S. Patent Office, a person applied for a
patent on what he called "cottonized silk," inclosing specimens. He
claimed that he had discovered a mode of covering cotton fiber with a
solution of silk which could be woven into goods of various kinds; in
order to satisfy the public of the reality of his invention, he placed on
exhibition, in various localities, specimens of silk-like goods in the
form of ribbons in the web and skeins of thread, representing them to be
"cottonized silk."

Dr. Dyrenforth was not satisfied that the so-called discovery was an
accomplished fact, and he forwarded a few fibers of the material to the
division of which I have charge for investigation. I subjected them to my
usual tests, and found them to consist of pure silk, and I so reported to
Dr. Dyrenforth, who rejected the application for a patent. The microscope
was thus usefully employed to protect capitalists from imposition.


METHODS EMPLOYED.

It may be well to state briefly the methods I employed in detecting the
real character of the material. The fibers were first viewed under plain
transmitted light, secondly, polarized light and selenite plate. Since
silk and cotton are polarizing bodies, "cottonized silk," if such could
be made as described, would give, in this case, the prismatic colors of
both fibers, and the complementary colors would differ greatly because of
the great disparity of their respective polarizing and refractive powers.

The fact will be observed that a cotton fiber presents the appearance of
a twisted ribbon when viewed by the microscope, while silk, owing to its
cylindrical form, cannot twist on itself. It should also be considered
that the diameter of "cottonized silk," so called, would be greater than
that of a fiber of silk, because the silk solution would have to be
applied to an actual thread of cotton, and not to a single cotton fiber,
by reason of the shortness of the original hairs of the latter. Were a
single fiber of such a combination put under a suitable objective, and a
drop of nitric acid brought in contact with the fiber, it would be seen
that the acid would destroy the silk and leave the fibers of cotton
untouched, the latter being insoluble in cold nitric acid. The action of
muriatic acid is similar in this respect. Were a fiber of cotton present
and a drop of pure sulphuric acid placed on it, followed quickly by a
drop of a transparent solution of the tincture of iodine, a peculiar
change in the fiber would take place, provided the right proportion of
acid be used. Cotton fiber, and especially flax fiber, under such
conditions, forms into disks or beads of a beautiful blue color.

Fig. 1 represents a cotton fiber, and 2, 3, 4, 5 those of flax, as they
appear under the acid treatment. Every textile amylaceous fiber is
convertible into these forms, more or less, by strong sulphuric acid. The
fibers of cotton, flax, and ramie are examples of amylaceous cellulose,
that is to say, these fibers are converted into starchy matter by
treatment with the last-named acid. Therefore combinations of these
fibers in any composition of non-amylaceous fiber (ligneous or woody
fiber) will be dissolved, leaving the latter unharmed; the woody fibers
remaining will prove suitable objects for examination under the
microscope.


COTTON MIXED WITH LINEN.

Again, it might be important to know whether a certain pulp or
composition contained flax in combination with cotton. The composition
might be of such a well-digested character as to destroy all appearance
of normal form, that is to say, the "twisted ribbon" character of cotton,
as well as that of the cylindrical and jointed characteristic of flax,
might be lost to ordinary view. In this case make a watery solution of
the pulp, spread it out thinly on a glass slide 3 inches by one, draw off
any superfluous water, then add one or two drops of a strong solution of
chromic acid to the preparation, and place over it a glass cover; when
viewed by the microscope, any portion of the flax joints present will
appear of a dark brown color; a solution of iodine has a similar effect.
The brown portions of the joints are nitrogenous in character; cotton
fibers are devoid of nitrogen.

[Illustration: Figs. 1, 2, 3, 4, 5.]


EXPERIMENTS WITH FLAX.

A chemist of the Department of Agriculture had once occasion to make
experiments with flax fibers, his object being to make them chemically
pure; and to this end he treated them with excess of bleaching agents,
thus rendering them of a beautiful white, silky appearance, to the naked
eye; but when I examined them under the microscope, I found the brown
nitrogenous matter of the joints still present, and on using the chromic
acid test, they became deeply stained. A chemical solution of flax
therefore would prove for some purposes undesirable, owing to the
presence of this ligneous matter. A chemical solution of cotton which is
destitute of ligneous matter will give a chemically pure solution. Cotton
is therefore better adapted than flax for collodion compounds.


WOOL TESTED WITH ACID.

It is known that when wool is treated with the sulphuric acid of commerce
or in strong dilute sulphuric acid, the surface scales of the fiber are
liberated at one end, and appear, under a low power, as hairs proceeding
from the body of the fibers. Wool may remain thus saturated in the acid
for several hours, without appearing to undergo any further change, as
far as is revealed by the microscope. When treated in mass in a bath of
sulphuric acid, strength 60° B., for several minutes, and afterward
quickly washed in a weak solution of soda, and finally in pure water and
dried, it feels rough to the fingers, owing to the separation of the
scales. I have preserved a small quantity of wool thus treated for the
last twelve years, my object being to ascertain whether the chemical
action to which it was exposed would impair its strength. As far as I can
observe, without the aid of the proper tests, it seems to have retained
its original tenacity. Wool thus treated seems to possess the property of
resisting the ravages of the larvæ of the moth. This specimen, although
openly exposed for the period named, suffered no injury from them. Under
the microscope, the lubrications appear to have resumed their natural
position, and appear finer.

From these experiments it would seem not improbable that a new article of
commerce might be produced from wool thus treated, considering that it
seems to be moth-proof.

I find in practice that when sable brushes are washed in a weak solution
of pure phenic alcohol and afterward in warm water, the moth worm will
not eat them. In this way I preserve sable brushes. I mention this
chemical fact because it shows that a change of this material is brought
about by the phenol as to its edibility, and this may explain why wool
treated with sulphuric acid is rendered moth-proof.

I find that when brain matter has been subjected to a solution of weak
phenic alcohol, weak alkaline solutions afterward applied fail to
separate its nerve-cells on the process of maceration. (This is probably
owing to its albuminoids being coagulated by the action of the phenol.)
When brain matter is subjected to a weak solution of soda alone, the
nerve-cells are easily separated by maceration, and well adapted for
microscopic use.


TESTS OF DYED BLACK SILK.

The fibers of dyed black silk may be viewed with interest under the
microscope. If a few threads of its warp are placed on a glass slide, and
one or two drops of concentrated nitric acid placed in contact with them,
the black color changes first to green, then to blue; a life-like motion
is observed in all the fibers; they appear marked crosswise like the
rings of an earthworm; the surface of each fiber appears loaded with
particles of dyestuff; finally the fibers wholly dissolve in the acid. If
we now treat a few threads of the weft in the same manner, a similar
change of color takes place. When the fibers assume the blue color, a
dark line is observed in the center of each, running longitudinally the
whole length; this dark line is doubtless the dividing line of the two
original normal threads formed directly by the two spinnerets; the dark
air line or shadow finally breaks up, and in the course of a few minutes
the silk is wholly dissolved. Were ramie, cotton, flax, or hemp present,
they would be observed, as all their fibers remain unchanged under this
treatment. If wool be present, rapid decomposition will follow, giving
off copious fumes of nitrous acid, allowing, however, sufficient time to
observe the separation of the scales of the fibers and to demonstrate by
observation under the microscope that the fibers are those of wool.

In making these experiments it is not necessary to use a glass disk over
the treated fibers. If a disk or cover is pressed on them while
undergoing this treatment, the life-like motion of the silk will not be
so apparent.

       *       *       *       *       *




IMPROVED PYROMETER.


Mr. John Frew, Langloan Iron Works, Coatbridge, has been successful in
perfecting a most ingenious pyrometer, an instrument which is capable of
continuously indicating every variation of temperature with a remarkable
degree of correctness. This instrument, which we here illustrate, has
already become known to a number of proprietors and managers of blast
furnaces; and on the occasion of the members of the Iron and Steel
Institute visiting Coatbridge, in connection with the meeting of that
body which was held in Glasgow last autumn, many persons became
interested in its construction and in the practical determination of
blast temperatures by its readings. Furthermore, Sir William Thomson has
expressed himself as being highly delighted with it on account of the
manner in which its use illustrates various beautiful scientific
principles.

The leading principle on which the construction of this pyrometer has
been based is the well-known law of the expansion of gases. Referring to
our engraving, it will be seen that at A is a pipe through which air from
the cold blast main is admitted into another and larger pipe, B, which
reaches nearly to the bottom of a water cistern, C. By means of the inlet
and outlet pipes, D and E, the height of the water in the cistern is
maintained at a uniform level. In this way there is provided a head of
water which retains within the pipe, B, a constant pressure of air,
equivalent to the head of water between the open end of that pipe and the
overflow at E. Any excess of pressure is prevented by means of the
open-ended pipe, which permits the air to escape by the central tube.
This latter prevents the agitation caused by the upward rushing air from
disturbing the level of the water in the cistern; and in order further to
assist this, the central tube is filled loosely in its upper part with
lead bullets or other suitable materials supported on a perforated plate.
The water level in the cistern is indicated by means of a glass gauge,
which is represented at G. To the upper end of the pipe, B, another pipe,
H, is attached. This is required for conveying the cold air to the
pyrometer proper, for the piece of apparatus above described is simply an
arrangement for securing a flow or current of air at constant pressure.

At any point where it is desired to fix a pyrometer, a connection is made
with the pipe last spoken of, by means of a small pipe such as is
indicated at J, into which is fixed a platinum or other metallic nozzle
of small bore, as shown at K. To this same pipe there is attached a
solid-drawn copper spiral heater or worm, L, which is fixed into the
place or the material the temperature of which it is desired to indicate.
Into the outlet of this worm another similar but larger nozzle, M, is
fixed. At N is shown a small pipe which is connected with the pipe, J, at
any convenient point between the inlet nozzle, K, and the spiral heater,
L. The other end of this pipe passes through the India rubber stopper of
a small cistern or bottle, O, which, when in use, is about two-thirds
filled with a colored liquid. It will be seen that the tube, N, only
passes through the stopper, so that it may convey pressure to the surface
of the liquid. At P is a glass tube which also passes through the stopper
and then to the bottom of the colored liquid; and as its upper end is
open, any variation of pressure in the spiral heater is directly
transmitted to the indicating column of colored liquid.

[Illustration: FREW'S PYROMETER.]

The operation of the instrument is as follows: As the cold blast used in
the apparatus would be useless for the working of the pyrometer if taken
direct from the cold blast main, owing to its irregularity of pressure,
the regulator that has been described is employed, and by its means an
absolutely steady flow of cold blast air at an unvarying pressure is
secured. The diameters of the inlet and outlet nozzles are so nicely
adjusted that, so long as both are at the same temperature, the outlet
nozzle, which is open to the atmosphere, will pass all the air that the
inlet nozzle can deliver without disturbing the pressure in the cistern,
O; but if heat be applied to the circulating air through the walls of the
spiral heater, the air expands in volume, and is unable to pass through
the outlet nozzle in its heated condition as rapidly as it is delivered
cold by the inlet nozzle. The consequence is that an increase of pressure
takes place in the apparatus between the two nozzles, and it is this
pressure that indicates the amount of heat that the air has taken up from
the hot blast pipe, in which the spiral heater is fixed. Then, again, as
this pressure is directly transmitted to the indicating liquid in the
cistern and the vertical tube immersed in it, a rise takes place in the
column which is in exact proportion to the expansion of the current of
blast passing through the spiral heater.

The method of graduating the indicator scales of the Frew pyrometer is
worthy of special notice. When the apparatus is fitted up, and before it
is permanently fixed in position, the spiral heater is placed in cold
water of known temperature, and the point noted at which the colored
liquid stands in the indicator tube. The water is then boiled, and the
rise in the liquid in the tube is again noted. Suppose, in the first
instance, the cold water temperature to be 62 deg. Fahr., and that, from
this point up to 212 deg. Fahr., the liquid to have risen 2¼ in. in the
tube; this is equal to 1½ in. per 100 deg. Fahr., and from these data a
scale is constructed, the correctness of which is easily verified by
transferring the spiral heater into an air bath or oil of high boiling
point, and then comparing the readings of the pyrometer scale with those
of a mercurial thermometer placed alongside of the spiral heater. By this
means it can be clearly demonstrated that, up to the highest point to
which it is safe to use a mercurial thermometer, the readings of the
pyrometer scale and that of the thermometer are identical.

While this pyrometer is particularly valuable for indicating the
temperature of hot blast stoves of every description, there are doubtless
many uses that will suggest themselves to persons engaged in various
industrial arts and manufactures. The apparatus is neat and substantial
in its parts, while it occupies very little space, is not at all liable
to derangement, and is entirely automatic in its action. A number of the
instruments have been in continuous use at the Langloan Iron Works, with
the most satisfactory results, for about eight months. The temperatures
they are graduated for vary according to the furnaces with which they are
connected and the kind of work to which these are
applied.--_Engineering_.

       *       *       *       *       *




An exchange gives the following very simple way of avoiding the
disagreeable smoke and gas which always pours into the room when a fire
is lit in a stove, heater, or fireplace on a damp day: Put in the wood
and coal as usual; but before lighting them, ignite a handful of paper or
shavings placed on top of the coal. This produces a current of hot air in
the chimney, which draws up the smoke and gas at once.

       *       *       *       *       *




[FROM PHOTOGRAPHISCHE CORRESPONDENZ.]

ORTHOCHROMATIC PLATES.

By CH SCOLIK.


Since the emulsion process has taken root, no improvement has awakened
such a lively, steadily increasing interest as photography of colored
objects in their correct tone proportions; a process which makes it
possible to reproduce the warmer color-tones, particularly yellow,
orange-red, and yellow-green, in their correct light value as they appear
to the eye.

In professional circles, as also among the public, the value of this
invention cannot possibly be underestimated; an invention with which a
new epoch in photography may begin, and by which the handsomest results,
particularly in reproductions of oil paintings, can be attained. But in
portraiture, as well as in landscape photography, recourse must also be
had to orthochromatic plates to obtain effective pictures, particularly
as plates can now be produced in which the relative sensitiveness closely
resembles that of the ordinary emulsion plate. Although a good deal has
been written about this subject, none of these sometimes excellent
treatises contains a complete and generally comprehensive formula for the
production of color-sensitive plates, and this circumstance causes me to
publish my own experiences.

The following coloring matters are particularly recommended in the
several publications as preferable:

Eosine yellow and eosine blue shade, iodine cyanin, erythrosine, methyl
violet, aniline violet, iodine green, azalein, Hoffmann's violet, acid
green, methyl green, rose bengal, pyrosine, chlorophyl, saffrosine,
coralline, saffranine, etc.

Particularly important is the correct concentration. The most excellent
color matters make the plates oftentimes quite useless by an incorrect
proportion of concentration. If this should be too strong, the total
sensitiveness will sink (decrease); but when too weak, the color
sensitiveness is much reduced.

This fault, particularly, cannot be corrected during washing, but I have
mentioned, at the end, how such overcolored emulsion can be made of use
before wetting (flowing).

By the addition of some coloring matter to the emulsion, the light
sensitiveness of the film toward some individual colored rays is
increased, but the sensitiveness for the stronger refractive rays is, as
a rule, generally reduced. The result is a loss of the total
sensitiveness for white light. Color-sensitive plates are therefore less
sensitive to light than ordinary plates of the same origin.

The action of the coloring matter depends also very essentially upon the
emulsion. If the emulsion contains iodide of silver, it has a greater
sensitiveness for light blue and blue-green light. At all events, the
iodide combination must not amount to more than one or two per cent., a
small quantity of iodine acting much better upon the total sensitiveness
of the plates than can be obtained by pure bromide of silver emulsion.

Methyl violet, rose bengal, and azalein act perceptibly in 1/10000 per
cent. upon yellow sensitiveness. Eosine and its varieties, eosine yellow
shade, or eosine J, pyrosine J, erythrosine yellowish, may all be noted
as very good sensitizers for green, yellow-green, and eventually for
yellow. The bluish shades of eosine colors, on the contrary, have an
absorption band further in the yellow. This is also the case with the
blue shade eosine (eosine B) and the most bluish of all eosines, the
bengal rosa. Of both eosines, yellow shade and blue shade, the latter
gives a little more intensity.

Although the eosine permits a large limit in the quantity, it will reduce
the sensitiveness greatly in larger quantity.

If eosine solution is mixed with bromide of silver emulsion, which is
entirely free from nitrate of silver, no eosine silver can form; it acts,
therefore, only as an optical sensitizer.

Of the several kinds of cyanin, chlorosulphate, nitrate, and iodide, the
latter acts best, as stated by Eder.

Schumann has already said that one drop of cyanin solution, 1 to 2,500 to
6½ c. c. emulsion, already acted as sensitizing in orange; five to ten
drops cyanin. 1 to 1,500 to 15 c. c. emulsion, even gave red action.

There are two ways to color the gelatine film with a suitable coloring
matter: by mixing the latter directly before filtering into the ready
made emulsion, to produce at once colored plates; or to bathe dry
emulsion plates for one to five minutes in a solution containing the
sensitizing coloring matter. The plates have previously to be soaked for
a few minutes, whereupon they are bathed in an aqueous alcoholic solution
(with eosine yellow shade and eosine blue shade, in a solution of 1 to
3,000; but with cyanin in a diluted solution of 1 to 5,000). A mixture of
1/10 cyanin and 9/10 eosine yellow shade (of above concentration) acts as
a very favorable sensitizer. Lohse recommended bathing of the gelatine
plates in a solution of 0.03 eosine and 10 c. c. ammonia in 100 parts of
water. He found that very diluted eosine solutions, 1 to 20,000, acted as
a yellow sensitizer.

After washing, the plates have to be rinsed and dried--colored plates, as
long as they remain moist, being less sensitive than dry ones, and very
seldom the reverse.

This bathing of the ready made plates may give good results, but pure and
faultless plates are very seldom obtained, wherefore the first mentioned
manner (direct addition of color to the emulsion) is to be preferred.

After the experiments made by me, eosine mixtures acted equally in the
yellow and blue shade; likewise mixtures of cyanin 1/10 and eosine yellow
shade 9/10 were the most favorable. The process with eosine underwent
first of all a thorough test, of which the following are the results.

The color, solution I made as follows:

I. 0.5 grm. eosine yellow shade in 750 c.c. alcohol (95 per cent.) is
dissolved under good shaking.

II. 0.5 grm. eosine blue shade is also dissolved in 750 c.c. alcohol.

(The emulsion preparation I do not repeat, supposing that everybody is
conversant with the same.)

To an emulsion after Monckhoven's method, I add, before filtering, above
eosine solutions to 1,000 c.c. emulsion, 15 c.c. each of yellow shade and
15 c.c. of blue shade eosine; mix with a glass stirring-rod, filter, and
begin the flowing of the plates. On the contrary, to an emulsion made
after Henderson's method, double the quantity of coloring matter can be
added before flowing, without reducing the sensitiveness perceptibly.

Cyanin and eosine mixtures I give in the following proportions;

III. 0.5 grm. cyanin (iodo-cyanin) dissolved in 1,000 c.c. alcohol under
good shaking.

(All coloring matter solutions have to be filtered.)

To 1,000 c.c. Monckhoven emulsion I give:

25 c.c. eosine solution, yellow shade (I.).

5 c.c. cyanine solution (III.).

With Henderson emulsion I increase to double the quantity.

Further experiments taught me that even if 60 to 80 c.c., and more, of
these coloring matter solutions were added, and the emulsion was left to
coagulate and then laid in alcohol for several days, after which it was
washed well, so that hardly any coloration could be observed, it showed,
when making a copy of an oil painting, that the color sensitiveness of
the emulsion was not reduced, and that it had rather increased in
relative sensitiveness.

Anyhow, I put every colored emulsion for eight days in alcohol, having
experienced that hereby, after washing, just a sufficient quantity of the
coloring matter will remain as is necessary for the color sensitiveness.

For the correctness of what I have said here, the following experiment
made by me will speak:

I mixed with an emulsion a quantity of coloring matter five times
increased, flowed a plate with same, which I then exposed, but obtained
no picture whatever.

The same emulsion I placed for fourteen days in alcohol, washed it well,
and flowed a plate again, which latter had not only the full color
sensitiveness, but almost equaled an ordinary emulsion plate in total
sensitiveness.

From this can be concluded that--as above said--by placing the emulsion
in alcohol, all superfluous coloring matter is removed from the same, and
that only the quantity necessary for the color sensitiveness remains
therein.

Further, it may be mentioned that it might be of advantage to add to all
emulsions eosine besides iodide of silver, because this will give to the
emulsion clearness and brilliancy besides color sensitiveness, and
produce fine lights.

Finally, I express the hope that these communications may be useful to
the practical photographer, and it is my intention to report also about
other coloring matters at some future time.--_H.D., in Anthony's
Bulletin._

       *       *       *       *       *




A NEW PHOTOGRAPHIC APPARATUS.


This apparatus consists of a box containing a camera, A, and a frame, C,
containing the desired number of plates, each held in a small frame of
black Bristol board. The camera contains a mirror, M, which pivots upon
an axis and is maneuvered by the extreme bottom, B. This mirror stops at
an angle of 45°, and sends the image coming from the objective to the
horizontal plate, D, at the upper part of the camera. The image thus
reflected is righted upon this plate.

[Illustration: NEW PHOTOGRAPHIC APPARATUS.]

As the objective is of short focus, every object situated beyond a
distance of three yards from the apparatus is in focus. In exceptional
cases, where the operator might be nearer the object to be photographed,
the focusing would be done by means of the rack of the objective. The
latter can also slide up and down, so that the apparatus need not be
inclined when buildings or high trees are being photographed. The door,
E, performs the _role_ of a shade. When the apparatus has been fixed upon
its tripod and properly directed, all the operator has to do is to close
the door, P, and raise the mirror, M, by turning the button, B, and then
expose the plate. The sensitized plates are introduced into the apparatus
through the door, I, and are always brought automatically to the focus of
the objective through the pressure of the springs, R. The shutter of the
frame, B, opens through a hook, H, with in the pocket, N. After exposure,
each plate is lifted by means of the extractor, K, into the pocket,
whence it is taken by hand and introduced through a slit, S, behind the
springs, R, and the other plates that the frame contains. All these
operations are performed in the interior of the pocket, N, through the
impermeable, triple fabric of which no light can enter.

An automatic marker shows the number of plates exposed. When the
operations are finished, the objective is put back in the interior of the
camera, the doors, P and E, are closed, and the pocket is rolled up. The
apparatus is thus hermetically closed, and, containing all the
accessories, forms one of the most practical of systems for the itinerant
photographer.--_La Nature._

       *       *       *       *       *




METEORITES.


In our SUPPLEMENT No. 529 we gave an abstract of Prof. Dewars recent
series of lectures on the above subject at the Royal Institution. We now
present an abstract of the last and concluding lecture.


THE DHURMSALA. METEORITE.

After the conclusion of his last lecture, Prof. Dewar distributed among
the younger listeners small pieces of a portion of the Dhurmsala
meteorite, which had been broken up for presentation to them by Mr. J.R.
Gregory, whose collection of rare minerals was recently to some extent
described in these pages. The lecturer stated that Sir F. Abel had given
him a large piece of a large meteorite, because he thought that the
speaker's piece ought to be bigger than theirs.

Professor Dewar also presented the listeners with a printed detailed
account of the fall of the Dhurmsala meteorite, including the report of
the occurrence sent to the Punjaub Government, and dated July 28, 1860.
The following are the main facts:

"On the afternoon of Saturday, the 14th of July, 1860, between the hours
of 2 and 2:30 P.M., the station of Dhurmsala was startled by a terrific
bursting noise, which was supposed at first to proceed from a succession
of loud blastings or from the explosion of a mine in the upper part of
the station; others, imagining it to be an earthquake or very large
landslip, rushed from their houses in the firm belief that they must fall
upon them. It soon became apparent that this was not the case. The first
report, which was far louder in its discharge than any volley of
artillery, was quickly followed by another and another, to the number of
fourteen or sixteen. Most of the latter reports grew gradually less and
less loud. These were probably but the reverberations of the former, not
among the hills, but among the clouds, just as is the case with thunder.
It was difficult to say which were the reports and which the echoes.
There could certainly not have been fewer than four or five actual
reports. During the time that the sound lasted the ground trembled and
shook convulsively. From the different accounts of three eyewitnesses
there appears to have been observed a flame of fire, described as about 2
ft. in depth and 9 ft. in length, darting in an oblique direction above
the station after the first explosion had taken place. The stones as they
fell buried themselves from 1 ft. to 1½ ft. in the ground, sending up a
cloud of dust in all directions. Most providentially, no loss of life or
property has occurred. Some coolies, passing by where one fell, ran to
the spot to pick up the pieces; before they had held them in their hands
half a minute they had to drop them, owing to the intensity of the cold,
which benumbed their fingers. This, considering the fact that they were
apparently but a moment before in a state of ignition, is very
remarkable. Each stone that fell bore unmistakable marks of partial
fusion."

Several meteors were seen at Dhurmsala on the evening of the same day.

Dr. C.T. Jackson analyzed a portion of one meteorite weighing 4½ oz.; the
piece was 2½ in. long, 1¼ in. wide, and 1 in. in average thickness. In
the course of his report he stated: "Its specific gravity is 3.456 at 68
deg. Fahr., barom. 29.9. Its structure is imperfectly granular, but not
crystallized, and there are small black specks of the size of a pin's
head, and smaller, of malleable meteoric iron, which are readily removed
from the crushed stone by the magnet. The color of the mass is ash gray.
A portion of the surface is black and is scarified by fusion. Its
hardness is not superior to that of olivine or massive chrysolite.
Chemical analysis shows that its composition is that of a ferruginous
olivine. One gramme of the stone, crushed in an agate mortar, and acted
on by a magnet, yielded 0.43 gramme of meteoric iron, which was
malleable. After the removal of this a qualitative analysis was made of
the residual powder. Another gramme was also taken, without picking out
the metallic iron, and was tested for chlorine and for phosphoric acid.
The results of the qualitative analysis were that the stone contains
silica, magnesia, a little alumina, oxide of iron and nickel, a little
tin, an alloy of iron and nickel, phosphoric acid, and a trace of
chlorine. These ingredients being determined, the plan for a quantitative
analysis was laid out, and was duly executed by the usual and approved
methods The following are the results of this analysis, per centum:

Silica, with traces of tin     40.000
Magnesia                       26.600
Peroxide of iron               27.700
Metallic iron                   3.500
Metallic nickel                 0.800
Alumina                         0.400
Chlorine                        0.049
Phosphoric acid not weighed       --
                               ______
                               99.049"

Messrs. Dewar and Ansdell analyzed the gases in the meteorite, of which
it contained three times its volume; the gases were in the following
proportions to each other:

Carbonic acid       61.29
Carbonic oxide       7.52
Hydrogen            30.96
Nitrogen             0.23
                   ______
                   100.00

       *       *       *       *       *




TELESCOPIC SEARCH FOR THE TRANS-NEPTUNIAN PLANET.

[Footnote: By David P. Todd, M.A., from the _Proceedings_ of the
American Academy of Arts and Science.]


In the twentieth volume of the _American Journal of Science_, at page
225, I gave a preliminary account of my search, theoretic and practical,
for the trans-Neptunian planet. I say _the_ trans-Neptunian planet,
because I regard the evidence of its existence as well-founded, and
further because, since the time when I was engaged upon this search,
nothing has in the least weakened my entire conviction as to its
existence in about that part of the sky assigned; while, as is well
known, the independent researches in cometary perturbations by Prof.
Forbes conducted him to a result identical with my own--a coincidence not
to be lightly set aside as pure accident.

That five years have elapsed since this coincidence was remarked, and the
planet is still unfound, is not sufficient assurance to me that its
existence is merely fanciful. In so far as I am informed, this spot of
the sky has received very little scrutiny with telescopes competent to
such a search; and most observers finding nothing would, I suspect,
prefer not to announce their ineffective search.

The time has now come when this search can be profitably undertaken by
any observer having the rare combination of time, enthusiasm, and the
necessary appliances. Strongly marked developments in astronomical
photography have been effected since this optical search was conducted;
and the capacity of the modern dry-plate for the registry of the light of
very faint stars makes the application of this method the shortest and
surest way of detecting any such object. Nor is this purely an opinion of
my own. But the required apparatus would be costly; and the instrument,
together with the services of an astronomer and a photographer, would,
for the time being, be necessarily devoted exclusively to the work.
While, however, the photographic search might have to be ended with a
negative result, in so far as the trans-Neptunian planet is concerned,
there would still remain the series of photographic maps of the region
explored, and these would be of incalculable service in the astronomy of
the future.

In the latter part of the paper alluded to above, I stated the
speculative basis upon which I restricted the stellar region to be
examined; also the fact that between November of 1877 and March of 1878 I
was engaged in a telescopic scrutiny of this region, employing the
twenty-six inch refractor of the Naval Observatory. For the purposes
contemplated I had no hesitation in adopting the method of search whereby
I expected to detect the planet by the contrast of its disk and light
with the appearance of an average star of about the thirteenth magnitude.
A power of 600 diameters was often employed, but the field of view of
this eye-piece was so restricted that a power of 400 diameters had to be
used most of the time. I say, too, that, "after the first few nights, I
was surprised at the readiness with which my eye detected any variation
from the average appearance of a star of a given faint magnitude; as a
consequence whereof my observing book contains a large stock of memoranda
of suspected objects. My general plan with these was to observe with a
sufficient degree of accuracy the position of all suspected objects. On
the succeeding night of observation they were re-observed; and, at an
interval of several weeks thereafter, the observation was again
verified." Subjoined to the original observations are printed these
verifications in heavy-faced type.

In conducting the search, the plans were several times varied in slight
detail, generally because experience with the work enabled me to make
improvements in method. Usually, I prepared every few days a new zone
chart of the region over which I was about to search; and these charts
while containing memoranda of all the instrumental data which could be
prepared beforehand, were likewise so adjusted with reference to the
opposition-time of the planet as to avoid, if possible, its stationary
point. The same thing, too, was kept in mind in selecting the times of
subsequent observation. Notwithstanding this precaution, however, it
would be well if some observer who has a large telescope should now
re-examine the positions of these objects.

Researches in faint nebulæ and nebulous stars appearing likely to
constitute a separate and interesting branch of the astronomy of the
future, it has seemed to me that the astronomers engaged in this work may
like to make a careful examination of some of the stars entered in my
observing book under the category of "suspected objects." The method I
adopted of insuring re-observation of these objects was by the
determination, not of their absolute, but only of their relative,
positions, through the agency of the larger "finder" of the great
telescope. This has an aperture of five inches, a power of thirty
diameters, and a field of view of seventy-eight minutes of arc. Two
diagrams were usually drawn in the book for each of these objects, the
one showing the relation of adjacent objects in the great telescope, and
the other the configuration of the more conspicuous objects in the field
of view of the finder. Adjacent to these "finder" diagrams are the
settings--to the nearest minute of arc in declination, and of time in
right ascension--as read from the large finding-circles, divided in black
and white. The field of view of the finder is crossed by two pairs of
hairlines, making a square of about twelve minutes on a side by their
intersection at the center. The diagrams in all cases represent the
objects as seen with an inverting eye-piece. As the adjustment of the
finder was occasionally verified, as well as the readings of the large
circles, there should be no trouble in identifying any of these objects,
notwithstanding the fact that no estimates of absolute magnitude were
recorded. The relative magnitudes, while intended to be only approximate,
are still shown with sufficient accuracy for the purpose of the research,
and the diagrams are, in general, faithful tracings from the original
memoranda.

[Mr. Todd transcribes the observing book entire.]

       *       *       *       *       *




[AMERICAN ANNALS OF THE DEAF AND DUMB.]

NOTES ON MANUAL SPELLING.


The inestimable value of speech-reading and the practicability of its
acquisition under favorable conditions is a matter of common experience
and observation but justice to the deaf requires a recognition of the
fact that speech-reading has its limitations. Certain English words,
chiefly short ones, are practically alike to the speech-reader and the
context may fail sometimes to give a clew. It is necessary, at times, in
communicating with even expert speech-readers, to have recourse to
writing or oral spelling to convey the names of persons, places,
technical terms, etc., not in common use. Moreover, it is convenient to
have accurate and rapid means of conversation under unfavorable
conditions as to light and distance, or when from any cause the deaf
person's voice cannot be heard.

Writing is slow, inconvenient, and often impossible. Writing upon the
palm of the hand was proposed by the Abbe Deschamps in 1778, as utilizing
the sense of touch, and was used in darkness by him as a substitute for
speech, but it is neither accurate nor rapid. Writing in the air[1] with
the finger is also slow and uncertain, while the action is unpleasantly
conspicuous.

[Footnote 1: The brilliant but wily Sicard, whose "show" pupils were
accustomed to honoring drafts at sight in appropriate responses to all
sorts of questions, acting upon the motto, _Mundus vult decipi, ergo
decipiatur_, schooled certain pupils in deciphering writing in the air,
and was thus prepared, in emergencies at his public exhibitions, to
convey intimations of the answers, while supposed to be using "signs" in
putting questions.]

Finger-spelling would appear to be a far more convenient, easy, rapid,
and accurate adjunct to speech or substitute for it than writing.

It is a common error to consider the ordinary manual alphabets as
deaf-mute alphabets and finger-spelling as the sign-language of the deaf.
Finger-spelling is to the deaf a borrowed art. It is used by many of the
educated deaf and their friends as a substitute for the sign-language,
and it enables them also to supply the deficiencies of the sign-language
by incorporating words from written language. Scagliotti, of Turin,
devised a system of initial signs[2] which begin with letters of the
manual alphabet, and Dr. Isaac Lewis Peet, of New York, has made a
similar application of manual letters to signs to suggest words of our
written language to the initiated deaf. But it should not be forgotten
that practice in finger-spelling is practice in our language.

[Footnote 2: _Quatrieme Circulaire_, Paris, 1836, p. 16. Carton's
_Memoire_, 1845, p. 73.]

The origin of finger-spelling is not known. Barrois, a distinguished
orientalist, in his _Dactylologie et Langage primitif_[3], ingeniously
traces evidences of finger-spelling, from the Assyrian antiquities down
to the fifteenth century upon monuments of art.

[Footnote 3: Barrois: _Dactylologie et langage primitif_, Paris, 1850,
Firmin Didot freres.]

The ancient Egyptians, Greeks, and Romans were familiar with manual
arithmetic and finger-numeration, as quaint John Bulwer shows by numerous
citations in his _Chironomia_ (1644). The earliest finger-alphabets
extant appear to have been based upon finger-signs for numbers, as, for
instance, that given by the Venerable Bede (672-735) in his _De Loguela
per Gestum Digitorum sive Indigitatione_, figured in the Ratisbon edition
of 1532.[4] Monks and others who had special reason to prize secret and
silent modes of communication, beyond doubt invented and used many forms
of finger alphabets as well as systems of manual signs.[5] The oldest
plates in the library of the National Deaf Mute College are found in the
_Thesaurus Artificiosae Memoriae_ of frater Cosmas P. Rossellius of
Florence, printed in 1579, which gives three forms of one-hand alphabets.
Bonet's work[6] of 1620 gives one form of the one hand Spanish manual
alphabet, which contains forms identical with certain letters in the
alphabets of 1579. This was introduced into France by Pereire and taught
to the Abbe de l'Epee by Saboureux de Fontenay, the gifted pupil of
Pereire. The good Abbe however continued to use a French[7] two-hand
alphabet which, he had learned when a child and which he said all
school-children knew. He mentions also a Spanish alphabet in part
requiring both hands, and remarks that different nations have different
manual alphabets. The Abbe Deschamps, a rival of De l'Epee, made use of a
finger alphabet in teaching the deaf to speak, which was not adapted to
rapid use. John Bulwer, in his _Chirologia, or the Naturall Language of
the Hand_, printed in 1644, figures five manual alphabets for secret
communication.

[Footnote 4: The library of the New York Institution contains a copy of
this very rare edition, bearing the title _Abacus atque velustissima
Latinorum per digitos manusque numerandi (quinetiam loquendi)
consuetudo_, etc., Ratisbonae, 1532.]

[Footnote 5: For an exhaustive account of the gesture speech in
Anglo-Saxon monasteries and of the Cistercian monks, who were
under rigid vows of silence, see F. Kluge: _Zur Geschichte der
Zeichensprache.--Angelsachsische indicia Monaslerialia,_ in
_International Zeitschrift fur Allgemeine Sprachwissenschaft,_ II. Band,
I. Halfte. Leipzig, 1885.]

[Footnote 6: _Reduccion de lasletras y arte para ensenar a hablar los
mudos_, 1620. The writer is under obligations to Sr. Santos M. Robledo,
of the Ministry of Public Works and Education, for advance sheets of the
reprint in beautiful facsimile of this rare work ordered by the Spanish
Government in 1881.]

[Footnote 7: The Abbe de l'Epee did not master the Spanish alphabet,
and, attaching but little importance to manual spelling, he was unsparing
in his criticism of _Messieurs the dactylologists_, but by "the irony of
fate" this alphabet occupies a face of the pedestal of one statue to his
memory, and in another statue the good Abbe is represented either as
receiving this alphabet from the skies or as devoutly using it.]

The first alphabet which appears to have been devised expressly for use
in teaching the deaf is that of George Dalgarno, of Aberdeen (1626-1687),
given in his remarkable philosophical treatise, _Didascalocophus, or the
Deaf and Dumb Man's Tutor_, Oxford, 1680. A facsimile of this alphabet is
given in the _Annals_, vol. ix., page 19. Words are spelled by touching
with your finger the positions indicated, either upon your hand or upon
the hand of your interlocutor. An alphabet of the same character,
however, was not unknown at an earlier date. For Bulwer, in 1648, says:
"A pregnant example of the officious nature of the Touch in supplying the
defect or temporall incapacity of the other senses we have in one Master
_Babington_ of _Burntwood_ in the County of _Essex_, an ingenious
gentleman, who through some sicknesse becoming _deaf_, doth
notwithstanding feele words, and as if he had an eye in his finger, sees
signes in the darke; whose Wife discourseth very perfectly with him by a
strange way of Arthrologie or Alphabet contrived on the joynts of his
Fingers; who taking him by the hand in the night, can so discourse with
him very exactly; for he feeling the joynts which she toucheth for
letters, by them collected into words, very readily conceives what shee
would suggest unto him. By which examples [referring to this case and to
that of an abbot who became _deaf, dumb_, and _blind_, who understood
writing traced upon his naked arm] you may see how ready upon any
invitation of Art, the _Tact_ is, to supply the defect, and to officiate
for any or all of the other senses, as being the most faithfull sense to
man, being both the _Founder_, and _Vicar generall_ to all the rest."[8]

[Footnote 8: _Philocophus_: or, THE DEAFE and Dumbe Mans Friend. By I.B.
[John Bulwer] sirnamed the _Chorosopher_. London, 1648. Pp. 106,107.]

Dr. Alexander Graham Bell has modified the Dalgarno alphabet, and has
made considerable use of it in its modified form as figured in the
_Annals_, vol. xxviii., page 133. He esteems it highly for certain
purposes, especially as employing touch to assist the sight or to release
the sight for other employment, as in reading speech for instance. Here a
touch-alphabet may be an efficient aid to the sight, as the touch may
fairly keep pace with the rapidity of oral expression in deliberate
speech. An objection of Dr. Kitto to the two-hand alphabet so widely know
by school-children and others in Great Britain and in this country would
seem to apply with greater force to the Dalgarno alphabet: "To hit the
right digit on all occasions is by far the most difficult point to learn
in the use of the [two-hand] manual alphabet, and it is hard to be sure
which fingers have been touched."[9]

[Footnote 9: Dr. Kitto remaks the following common mistakes in reading
rapid two-hand spelling: the confounding _i_ with _e_ or _o_; _d_ with
_p_; _l_ with _t_; _f_ with _x_; _r_ with _t_ and with one form of _j_;
_n_ with _v_, and adds: "Upon the whole, the system is very defective,
and is capable of great improvement." _--The Lost Senses_, p. 107.]

It is not the purpose of the writer to attempt even a catalogue of the
numerous finger alphabets, common, tactile, phonetic, "phonomimic,"
"phonodactylologic," and syllabic, which have been proposed for the
special use of the deaf.

The one-hand alphabet used by Ponce and figured by Bonet was common in
Spanish almanacs hawked by ballad-mongers upon the streets of Madrid in
the days of De l'Epee, and although rejected by him, it was adopted by
his pupils. This with slight modifications became the French manual
alphabet which was introduced at Hartford by Dr. Thomas Hopkins
Gallaudet. This alphabet is known in almost every hamlet in the land.
Slight changes in the form of certain letters, or in the position of the
hand, in the direction of greater perspicuity and capacity for rapid use,
have taken place gradually, though there is no absolute uniformity of
usage among instructors or pupils.

This "American" alphabet, as here presented, through the liberality of
Dr. A. Graham Bell, has been drawn and engraved from photographs, and
represents typical positions of the fingers, hand and fore-arm from a
uniform point of view in front of the person spelling, or as seen in a
large mirror by the user himself.[10]

[Footnote 10: See an interesting paper on figured manual alphabets by
H.H. Hollister, _Annals_, xv., 88-93.]

This alphabet can be learned in less than an hour, and many have learned
it by extraordinary application in ten minutes. It is recommended that
the arm be held in an easy position near the body, with the fore-arm as
in the plates. Each letter should be mastered before leaving it. Speed
will come with use; it should not be attempted nor permitted until the
forms of the letters and the appropriate positions of the hand are
thoroughly familiar. The forms as given are legible from the distant
parts of a public hall. In colloquial use the fingers need not be so
closely held nor firmly flexed, as represented, but sprawling should be
avoided. It is not necessary to move the arm, but a slight leverage at
the elbow is conducive to ease and is permissible, provided the hand
delivers the letters steadily within an imaginary immovable ring of, say,
ten inches in diameter.

[Illustration: THE ONE-HAND ALPHABET IN GENERAL USE.--FRONT VIEW.]

This adjunct to speech-reading is recommended for its convenience,
clearness, rapidity, and ease in colloquial use, as well as for its value
as an educational instrument in impressing words, phrases, and sentences
in their spelled form upon the mind, in testing the comprehension of
children, and in affording by easy steps a substitute for the
sign-language.

In the simultaneous instruction of large classes not able to follow
speech, finger-spelling "may take the place of signs to a great extent in
the definition, explanation, and illustration of single words and
phrases, and in questions and answers upon the lessons, and in
communications of every kind to which the stock of language already
acquired may be adequate."[11]

[Footnote 11: _The Use of the Manual Alphabet_, by S. Porter: Proceedings
of the Eighth Convention of American Instructors, pp. 21-30. Copies of
the Proceedings which contain this extremely valuable paper may be
obtained of R. Mathison, Superintendent of the Ontario Institution,
Belleville, Ontario.]

All who have anything to do with the school instruction of the deaf may
well bear in mind the matured opinion and wise counsel of Professor
Samuel Porter, of the National College, the Nestor of American
instructors. In this connection, Professor Porter says:

_In short, let the gestural signs come in only as a last resort, or, so
far as possible, merely as supplementary to words, re-enforcing them in
some instances, or employed as a test of the pupil's knowledge of words,
but always, so far as possible, falling behind and taking a subordinate
place. And let the pupils be required, in what they have to say to their
teachers in the schoolroom or elsewhere, to employ the finger-alphabet
instead of natural signs to the utmost possible extent, and this by
complete sentences and not in a fragmentary way_.

JOSEPH C. GORDON, M.A.,

_Professor in the National College, Washington, D.C._.

       *       *       *       *       *




FRUITS AND SEEDS FOR DRESS-TRIMMING.


The use of natural flowers for decorating the person is instinctive among
certain peoples, and a question of fashion among others. It is in
Oceanica especially that this taste seems to be nationally developed, and
from the narrative of Cook we know that the Tahitian belles use in their
toilet the perfumed flowers of the pua and tiare (_Carissa grandis_ and
_Gardenia Tahitensis_), whose dazzling whiteness renders still more
marked the ebony blackness of their wealth of hair.

In Europe this custom is traditional in many countries. Women of fashion
scarcely ever appear at a soiree or ball without wearing a camellia or an
exotic orchid on their breast or in their head-dress, and so, too,
gentlemen of "high life" do not go out without a boutonniere of white
violets or Cape jasmine.

But natural flowers, being ephemeral, were once replaced in the toilets
of ladies by artificial ones. The artificial flower industry originated
in China, and from thence passed into Italy and afterward into France. In
course of time people got tired of artificial flowers for decorative
purposes, and then imitation fruits made their appearance, and were worn
in the toilets of dowagers and mothers of families.

Now that fashion, that tyrant born of dressmakers, milliners, and tailors
of renown, obliges us to clothe ourselves according to accepted models,
the kaleidoscope no longer suffices to find the most varied designs and
most fantastic cuts for garbs or ornament.

In recent years pleasing objects have been borrowed from the animal
kingdom, such as small birds and quadrupeds, and insects with brilliant
colors and of strange forms. What formerly would have been a repulsive
object (such as a great longicorn or beetle) is worn with ease by the
belles of our time. The use of such objects of natural history, however,
has been about confined to the decoration of head-dresses or the
manufacture of jewelry.

[Illustration: FIG. 1.--DRESS TRIMMINGS OF FRUITS AND SEEDS. 1. Seeds
of _Casuarina_ and fruit of alder. 2. Acorn cup, involcure of beech, and
pod of medick. 3. Fruit of _Eucalyptus_, cups of acorns, Job's tears, and
cones of cypress.]

As the need of creating new models is always making itself felt, one
ingenious manufacturer, Mr. Collin, has turned toward the vegetable
kingdom, and brought out an elegant and original style of dress-trimming
made of certain indigenous and exotic fruits and seeds that no one would
ever have thought of using for such a purpose. Instead of pendants made
of wood and covered with silk or velvet, Mr. Collin uses dry fruits or
seeds, which he has previously dyed, gilded, or silvered.

[Illustration: FIG. 2.--DRESS TRIMMINGS OF FRUITS AND SEEDS. 4 and 5.
Fruit of alder. 6. Fruit of _Casuarina_. 7. Fruit of _Arbutus_. 8. Fruit
of _Casuarina_.]

In order that the effect may be good, it is necessary that the objects be
not uniform. Their surface must be naturally carved and hollowed, and the
projecting parts must detach themselves well from each other. The number
of species now used is relatively large, but a selection from these will
inevitably be made. Some patterns will be better liked than others, and
ladies who are to wear these new trimmings this winter will be able to
make their choice of them at the fashion stores. When such articles as
these make their appearance, they often spread with surprising rapidity.
It is now but a few days since the great dressmaker Worth adopted them,
and the linen trade already has them in stock. We recently saw at
Suzange's some linen aprons and collars ornamented with small groups of
fruits and seeds prepared by the Collin process, and which produced a
most pleasing effect. The idea has even occurred to apply these trimmings
to furniture and upholstery.

In the manufacture of these articles the cones of several species of
_Casuarina_, the tags of alder, as well as the naturally carved fruits of
certain _Eloeocarpi_ of India and Australia, were first used; then came
the fruits of the umbelliferous plant, _Oenanthe_, the spiral pods of
_Medicago_, the fruit of the water-caltrops, _Melia_ and _Zizyphus_, the
cups of the acorn, the involucres of the beech, the seeds of _Coix
lacryma_, etc.

The naturalist ought to be glad to see objects that form the base of his
studies taking a direction favorable to the industry of his country.

On another hand, these products themselves cannot fail to arouse the
curiosity of ladies who have the instinct of observation. And, who knows?
Perhaps a frock or mantle trimmed with these vegetable ornaments may
prove a more certain propaganda in favor of botany than the most classic
lessons on this gentle, science!--_La Nature_.

       *       *       *       *       *




DEW.

[Footnote: Abstract of paper read before the Royal Society of
Edinburgh on Dec. 21, 1885, by Mr. Aitken, communicated by permission of
the Council of the Society.--_Nature_.]


The first point referred to in this paper is the source of the vapor that
condenses to form dew. A short historical sketch is given of the
successive theories from time to time advanced on this point, showing
how in early times dew was supposed to descend from the heavens, and then
afterward it was suggested that it rose from the earth, while Dr. Wells,
who has justly been considered the great master of this subject, thought
it came neither from above nor from below, but was condensed out of the
air near the surface of the earth. He combated Gersten's idea that it
rose from the earth, and showed that all the phenomena observed by
Gersten and others which were advanced to support this theory could be
equally well explained according to the theory that it was simply formed
from the vapor present at the time in the air, and which had risen from
the ground during the day, and concluded that if any did rise from the
ground during night, the quantity must be small, but, with great caution,
he adds that "he was not acquainted with any means of determining the
proportion of this part to the whole."

A few observations of the temperature of the ground near the surface, and
of the air over it, first raised doubts as to the correctness of the now
generally received opinion that dew is formed of vapor existing at the
time in the air. These observations, made at night, showed the ground at
a short distance below the surface to be always hotter than the air over
it, and it was thought that so long as this excess is sufficient to keep
the temperature of the surface of the ground above the dew point of the
air, it will, if moist, give off vapor, and it will be this rising vapor
that will condense on the grass and form dew, and not the vapor that was
previously present in the air.

The first question to be determined was whether vapor does, or does not,
rise from the ground on dewy nights. One method tried of testing this
point was by placing over the grass, in an inverted position, shallow
trays made of thin metal and painted. These trays were put over the
ground to be tested after sunset and examined at night, and also next
morning. It was expected that, if vapor was rising from the ground during
dewy nights, it would be trapped inside the trays. The result in all the
experiments was that the inside was dewed every night, and the grass
inside was wetter than that outside. On some nights there was no dew
outside the trays, and on all nights the inside deposit was heavier than
the outside one.

An analysis of the action of these trays is given, and it is concluded
that they act very much the same as if the air was quite still. Under
these conditions vapor will rise from the ground so long as the
vapor-tension on the surface of the ground is higher than that at the top
of the grass, and much of this rising vapor is, under ordinary
conditions, carried away by the passing air, and mixed with a large
amount of drier air, whereas the vapor rising under the trays is not so
diluted; and hence, though only cooled to the same amount as the air
outside, it yields a heavier deposit of dew.

Another method of testing this point was employed, which consisted in
weighing a small area of the exposed surface of the ground, as it was
evident that if the soil gave off vapor during a dewy night, it must lose
weight. A small turf about 6 inches (152 mm.) square was cut out of the
lawn, and placed in a small shallow pan of about the same size. The pan
with its turf, after being carefully weighed, was put out on the lawn in
the place where the turf had been cut. It was exposed for some hours
while dew was forming, and on these occasions it was always found to lose
weight. It was thus evident that vapor was rising from the ground while
dew was forming, and therefore the dew found on the grass was formed of
part of the rising vapor, trapped or held back by coming into contact
with the cold blades of grass.

The difference between these experiments, in which the exposed bodies
_lose_ weight, and the well-known ones in which bodies are exposed to
radiation, and the amount of dew formed is estimated by the _increase_ in
their weight, is pointed out. In the former case, the bodies are in good
heat-communication with the ground, whereas in the latter little or no
heat is received by conduction from the earth.

Another method employed for determining whether the conditions found in
nature were favorable for dew rising from the ground on dewy nights was
by observations of the temperatures indicated by two thermometers, one
placed on the surface of the grass and the other under the surface, among
the stems, but on the top of the soil. The difference in the readings of
these two thermometers on dewy nights was found to be very considerable.
From 10° to 18° F. was frequently observed. A minimum thermometer placed
on, and another under, the grass showed that during the whole night a
considerable difference was always maintained. As a result of this
difference of temperature, it is evident that vapor will rise from the
hotter soil underneath into the colder air above, and some of it will be
trapped by coming into contact with the cold grass.

While the experiments were being conducted on grass land, parallel
observations were made on bare soil. Over soil the inverted traps
collected more dew inside them than those over grass. A small area of
soil was spread over a shallow pan, and after being weighed was exposed
at the place where the soil had been taken out, to see if bare soil as
well as grass lost weight during dewy nights. The result was that on all
nights on which the tests were made the soil lost weight, and lost very
nearly the same amount as the grass-land.

Another method employed of testing whether vapor is rising from bare
soil, or is being condensed upon it, consisted in placing on the soil,
and in good contact with it, small pieces of black mirror, or any
substance having a surface that shows dewing easily. In this way a small
area of the surface of the earth is converted into a hygroscope, and
these test surfaces tell us whether the ground is cooled to the dew-point
or not. So long as they remain clear and undewed, the surface of the soil
is hotter than the dew-point, and vapor is being given off, while if they
get dewed, the soil will also be condensing vapor. On all nights
observed, these test-surfaces kept clear, and showed the soil to be
always giving off vapor.

All these different methods of testing point to the conclusion that
during dewy nights, in this climate, vapor is constantly being given off
from grass land, and almost always from bare soil; that the tide of vapor
almost always sets outward from the earth and but rarely ebbs, save after
being condensed to cloud and rain, or on those rarer occasions on which,
after the earth has got greatly cooled, a warm moist air blows over it.
The results of the experiments are given, showing, from weighings, the
amount of vapor lost by the soil at night, and also the heat lost by the
surface soil.

It seems probable that when the radiation is strong, that soil,
especially if it is loose and not in good heat-communication with the
ground, will get cooled below the dew-point, and have vapor condensed
upon it. On some occasions the soil certainly got wetter on the surface,
but the question still remains, Whence the vapor? Came it from the air,
or from the soil underneath? The latter seems the more probable source;
the vapor rising from the hot soil underneath will be trapped by the cold
surface-soil, in the same way as it is trapped by grass over grass-land.
During frost, opportunities are afforded of studying this point in a
satisfactory manner, as the trapped vapor keeps its place where it is
condensed. On these occasions the under sides of the clods, at the
surface of the soil, are found to be thickly covered with hoar-frost,
while there is little on their upper or exposed surfaces, showing that
the vapor condensed on the surface-soil has come from below.

The next division of the subject is on dew on roads. It is generally said
that dew forms copiously on grass, while none is deposited on roads,
because grass is a good radiator and cools quicker, and cools more, than
the surface of a road. It is shown that the above statement is wrong, and
that dew really does form abundantly on roads, and that the reason it has
not been observed is that it has not been sought for at the correct
place. We are not entitled to expect to find dew on the surface of roads
as on the surface of grass. because stones are good conductors of heat,
and, the vapor-tension being higher underneath than above the stones, the
result is, the rising vapor gets condensed on the under sides of the
stones. If a road is examined on a dewy night, and the gravel turned up,
the under sides of the stones are found to be dripping wet.

Another reason why no dew forms on the surface of roads is that the
stones, being fair conductors, and in heat communication with the ground,
the temperature of the surface of the road is, from observations taken on
several occasions, higher than that of the surface of the grass
alongside. The air in contact with the stones is, therefore, not cooled
so much as that in contact with the grass.

For studying the formation of dew on roads, slates were found to be
useful. One slate was placed over a gravelly part of the road, and
another over a hard dry part. Examined on dewy nights, the under sides of
these slates were always found to be dripping wet, while their upper
surfaces, and the ground all round, were quite dry.

The importance of the heat communicated from the ground is illustrated by
a simple experiment with two slates or two iron weights, one of them
being placed on the ground, either on grass or on bare soil, and the
other elevated a few inches above the surface. The one resting on the
ground, and in heat-communication with it, is found always to keep dry on
dewy nights, whereas the elevated one gets dewed all over.

The effect of wind in preventing the formation of dew is referred to. It
is shown that, in addition to the other ways already known, wind hinders
the formation of dew by preventing an accumulation of moist air near the
surface of the ground.

An examination of the different forms of vegetation was made on dewy
nights. It was soon evident that something else than radiation and
condensation was at work to produce the varied appearances then seen on
plants. Some kinds of plants were found to be wet, while others of a
different kind, and growing close to them, were dry, and even on the same
plant some branches were wet, while others were dry. The examination of
the leaf of a broccoli plant showed better than any other that the
wetting was not what we might expect if it were dew. The surface of the
leaf was not wet all over, and the amount of deposit on any part had no
relation to its exposure to radiation or access to moist air; but the
moisture was collected in little drops, placed at short distances apart,
along the very edge of the leaf. Closer examination showed that the
position of these drops had a close relation to the structure of the
leaf; they were all placed at the points where the veins in the leaf came
to the outer edge, at once suggesting that these veins were the channels
through which the liquid had been expelled. An examination of grass
revealed a similar condition of matters; the moisture was not equally
distributed over the blade, but was in drops attached to the tips of some
of the blades. These drops, seen on vegetation on dewy nights, are
therefore not dew at all, but are an effect of the vitality of the plant.

It is pointed out that the excretion of drops of liquid by plants is no
new discovery, as it has been long well known, and the experiments of Dr.
Moll on this subject are referred to; but what seems strange is that the
relation of it to dew does not seem to have been recognized.

Some experiments were made on this subject in its relation to dew. Leaves
of plants that had been seen to be wet on dewy nights were experimented
on. They were connected by means of an India-rubber tube with a head of
water of about one meter, and the leaf surrounded with saturated air. All
were found to exude a watery liquid after being subjected to pressure for
some hours, and a broccoli leaf got studded all along its edge with
drops, and presented exactly the same appearance it did on dewy nights. A
stem of grass was also found to exude at the tips of one or two blades
when pressure was applied.

The question as to whether these drops are really exuded by the plant, or
are produced in some other way, is considered. The tip of a blade of
grass was put under conditions in which it could not extract moisture
from the surrounding air, and, as the drop grew as rapidly under these
conditions as did those on the unprotected blades, it is concluded that
these drops are really exuded by the plant. Grass was found to get
"dewed" in air not quite saturated.

On many nights no true dew is formed, and nothing but these exuded drops
appear on the grass; and on all nights when vegetation is active, these
drops appear before the true dew; and if the radiation is strong enough
and the supply of vapor sufficient, true dew makes its appearance, and
now the plants get equally wet all over, in the same manner as dead
matter. The difference between true dew on grass and these exuded drops
can be detected at a glance. The drops are always exuded at a point near
the tip of the blade, and form a drop of some size, while true dew is
distributed all over the blade. The exuded liquid forms a large
diamond-like drop, while the dew coats the blade with a pearly luster.

Toward the end of the paper the radiating powers of different surfaces at
night is considered, and after a reference to some early experiments on
this subject, the paper proceeds to describe some experiments made with
the radiation thermometer described by the author in a previous paper.
When working with this instrument, it is placed in a situation having a
clear view of the sky all round, and is fixed at the same height as the
ordinary thermometer screen, which is worked along with it, the
difference between the thermometer in the screen and the radiation
thermometer being observed. This difference in clear nights amounts to
from 7° to 10°. By means of the radiation thermometer the radiating
powers of different surfaces were observed. Black and white cloths were
found to radiate equally well; soil and grass were also almost exactly
equal to each other. Lampblack was equal to whitening. Sulphur was about
two-thirds of black paint, and polished tin about one-seventh of black
paint. Snow in the shade on a bright day was at midday 7° colder than the
air, while a black surface at the same time was only 4° colder. This
difference diminished as the sun got lower, and at night both radiated
almost equally well. In the concluding pages of the paper some less
important subjects are considered.

       *       *       *       *       *


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