Chapter 1

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SCIENTIFIC AMERICAN SUPPLEMENT NO. 623

NEW YORK, DECEMBER 10, 1887

Scientific American Supplement. Vol. XXIV., No. 623.

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. ARCHITECTURE.--Notes on the Construction of a Distillery Chimney--A new method of building lofty shafts, including a metallic frame and brick lining--3 illustrations. 9949

The Commercial Exchange, Paris--The new Paris exchange now in process of erection.--Present state of operations--1 illustration. 9954

II. ASTRONOMY.--The Yale College Measurement of the Pleiades.-- Dr. Elkin's work with the Repsold heliometer at Yale College. 9957

III. CHEMISTRY--New Method for the Quantitative Determination of Starch.--By A.N. ASBOTH--Determination of starch by its barium compound. 9956

Synthesis of the Alkaloids--A retrospect of the field of work so far traveled over by synthetical chemists, and future prospects. 9956

The Chemical Basis of Plant Forms--By HELEN C. DE S. ABBOTT --Continuation of this important contribution to plant chemistry, one of the most valuable of recent chemical monographs. 9955

IV. ELECTRICITY.--An Electrical Governor--A new apparatus for preserving a constant electromotive force with varying dynamo speed--1 illustration. 9952

Electric Launch--A French government launch with Krebs electric motor. 9954

The electric current as a means of increasing the tractive adhesion of railway motors and other rolling contacts.--By ELIAS E. RIES--A full review of this important subject, with accounts of its experimental examination. 9953

V. ENGINEERING--Benier's Hot Air Engine--A new caloric engine very fully illustrated and described--8 illustrations. 9943

Heating Marine Boilers with Liquid Fuel--A simple apparatus and recent experiments with the same.--3 illustrations. 9945

The Change of Gauge of Southern Railroads in 1886--By C.H. HUDSON.--The conclusion of the account of this great engineering feat, with tables of statistics and data--16 illustrations. 9946

Your Future Problems--By CHAS. E. EMERY--An address to the graduating class of the Stevens Institute, N.J.--A practical view of the engineering profession. 9943

VI. MISCELLANEOUS--A Group of Hampshire Downs--A typical breed of sheep, their qualities and habits.--1 illustration. 9957

VII. NAVAL ENGINEERING--The Spanish Cruiser Reina Regente--A further description of this celebrated vessel--4 illustrations. 9948

Torpedo Boats for Spain--The Azor and Halcon, two Yarrow torpedo boats, described and illustrated--7 illustrations. 9947

VIII. PHOTOGRAPHY--How Different Tones in Gelatino-chloride Prints may be Varied by Developers.--Twenty different formulæ for the above purpose. 9949

Film Negatives--Eastman stripping films, their manipulation and development. 9949

IX. SANITATION--French Disinfecting Apparatus--A portable apparatus for disinfecting clothes and similar objects--1 illustration. 9952

X. TECHNOLOGY.--The Manufacture of Cocaine--The extraction of cocaine with alkali and petroleum, with statement of percentage yielded by various leaves. 9954

The Production of Oxygen by Brin's Process--The commercial manufacture of oxygen by means of baryta--3 illustrations. 9950

#Transcriber's Note: Following entry not in original table of contents#

Deep Sea Dredgings: Examination Of Sea Bottoms. By THOMAS 9958 T.P. BRUCE WARREN.

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BENIER'S HOT AIR ENGINE.

The hot air engine, although theoretically recognized for some time past as the most economical means of converting heat into motive power, has up to the present met with little success. This is due to the fact that the arrangement of the motors of this class that have hitherto been constructed has been such as to render them but slightly practical. In the Benier hot air engine (illustrated herewith), however, obstacles that were once considered insurmountable have been overcome, and the motor presents many advantages over all the types that have preceded it. Among such advantages we shall cite the possibility of utilizing air at a high temperature (1,200 or 1,500 degrees), while the rubbing surfaces remain at a moderate temperature (60 or 80 degrees). The fire grate is placed in the interior of the cylinder, and is traversed by the cold air forced by a pump. The expanded hot gases fill the cylinder and act against the piston directly above the grate.

The type herewith illustrated is of 6 horse power. The motive cylinder, CC', is bolted to the extremity of the frame, A. Upon this latter is fixed a column, B, which carries a working beam, E. This latter transmits the motion of the piston, P, to the shaft, D. A pump, G, placed within the frame, forces a certain quantity of cold air at every revolution into the driving cylinder. The piston of this pump is actuated by the connecting rod, G', jointed to the lever, F', which receives its motion from the rod, F. A slide valve, _b'_, actuated by a cam, regulates the entrance of the cold air into the pump during suction, as well as its introduction into the cylinder. There is a thrust upon the piston during its upward travel, and an escape of hot gas through the eduction valve, _h_, during the downward travel.

The cylinder is in two parts, C and C'. The piston, which is very long, rubs at its upper end against the sides of the cylinder, C. The lower end is of smaller diameter, and leaves an annular space between it and the cylinder. The grate is at the bottom of the cylinder, C'. The sides of the cylinder at the level of the fire box are protected with a lining of plumbago. When the piston is at the bottom of its travel, the eduction valve closes. The slide valve, _b'_, establishes a communication between the pump chamber and the cylinder. The air contained in the pump is already compressed in the latter to a pressure of nearly a kilogramme at the moment of the communication. This air enters the cylinder, and the communication between the latter and the pump continues until all the air is forced into the driving cylinder, the piston of the pump being at the bottom of its travel, and that of the cylinder about midway.

The air forced by the pump piston enters the cylinder through two conduits, one of which leads a portion of it toward the top of the cylinder, and the other toward the bottom. The lower conduit debouches under the grate, and the air that passes through it traverses the fire box, and the hot gas fills the cylinder. The conduit that runs to the top debouches in the cylinder, C, at the lower limit of the surface rubbed by the piston. The air that traverses this conduit is distributed through the annular space between the piston and cylinder. The hot gas derived from combustion can therefore never introduce itself into this annular space, and consequently cannot come into contact with the rubbing surfaces of the cylinder and piston.

As the quantity of air introduced at every stroke is constant, the work developed at every stroke is varied by regulating the temperature of the gas that fills the cylinder. When the temperature falls, the pressure, and consequently the work developed, diminishes. This result is obtained by varying the respective quantities of air that pass through the fire box and around the piston. In measure as less air passes through the fire box, the quantity that passes around the piston augments by just so much, and the pressure diminishes. A valve, _n'_, in the conduit that runs to the fire box is controlled by the regulator, L', in the interior of the column. When the work to be transmitted diminishes, the regulator closes the valve more or less, and the work developed diminishes.

The coke is put by shovelfuls into a hopper, I. Four buckets mounted upon the periphery of a wheel, I', traverse the coke, and, taking up a piece of it, let it fall upon the cover, J, of the slide valve, _j_, whence it falls into the cavity of the latter when it is uncovered, and from thence into the conduit, _c'_, of the box, _j'_, when the cavity of the valve is opposite the conduit. From the conduit, _c'_, the coke falls upon the grate.

A small sight hole covered with glass, in the cover, J, permits the grate to be seen when the cavity of the valve is opposite _c'_.

As in gas engines, a current of water is made to flow around the cylinder, C', in order to keep the sides from getting too hot.

In order to set the engine in motion, we begin by opening the bottom, C, of the cylinder, C', to clean the grate. This done, we close C and introduce lighted charcoal through the conduit, _c'_ (the valve being open). The valve is put in place, two or three revolutions are given to the fly wheel, and the motor starts. The feeding is afterward done with coke.

The parts that transmit motion operate under conditions analogous to those under which the same parts of a steam engine do. The air pump sucks and forces nothing but cold air, and nothing but cold air passes through the distributing slide valve. The pump and valve are therefore rendered very durable. The piston and cylinder, at the points where friction exists, are at a temperature of 60 or 80 degrees. These surfaces are protected against hot gas charged with dust.

The hot gas, which escapes from the cylinder through a valve, has previously been cooled by contact with the sides of the cylinder and by expansion. The eduction valve just mentioned works about like that of a steam engine, and it is only necessary to polish it now and then in order to keep it in good condition.--_Annales Industrielles._

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YOUR FUTURE PROBLEMS.[1]

[Footnote 1: An address to the graduating class, Stevens Institute, Hoboken, N.J., 1887.]

By CHARLES E. EMERY.

_Mr. President and Ladies and Gentlemen:_ It has not been considered the duty of the speaker, in addressing the graduating class, to dwell on the triumphs of science or the advantage of a liberal education. These subjects have already been discussed, in connection with the regular courses of study, better, and more at length, than he could do. We propose rather to try and prepare the minds of the graduates for the practical problems before them.

All young men are impressed with the consciousness of higher powers as they increase their stores of knowledge, and this feeling perhaps reaches its maximum with those who have made a specialty of the investigation and application of physical laws. Young men who have learned how to harness the powers of nature and guide them to do their will are apt to belittle the difficulties they have yet to overcome, and have a false impression of the problems of life. This feeling is shown to a minimum extent by graduates of the Stevens Institute, on account of their careful practical training, in connection with the thorough study of principles; but it has been thought best for one from the outside world to supplement such teaching by calling to mind instances which may have a useful counteracting effect, and, like parables, serve the purpose of illustrative instruction.

_Gentlemen of the Class of '87_: It was the pleasure of the speaker to address the class of '79, under the title of "How to Succeed," some words of counsel and warning, which, if they left an impression of severity at the time, were apparently so well received afterward that he has been tempted to continue the general subject, with the title of "Your Future Problems." The notation of your future problems will not be found at once among the known quantities, but with _x_, _y_, and _z_, at the other end of the alphabet. Often word symbols will be applicable, expressing at times disappointment and pain, at other times renewed effort, and finally the active phases of individual thought and exertion.

The first serious problem with many of you will be to secure satisfactory engagements. This problem cannot be illustrated by parables. It needs, in general, patient, unremitting, and frequently long continued effort. It may be that the fame of some of you, that have already acquired the happy faculty of making yourselves immediately useful, has already gone abroad and the coveted positions been already assured. To be frank, we cannot promise you even a bed of roses. We have in mind an instance where a superior authority in a large business enterprise who had great respect, as he should have, for the attainments of young gentlemen who have had the opportunities of a technical education, deliberately ordered out a competent mechanical engineer, familiar with the designs required in a large repair shop, and sent in his place a young gentleman fresh from school and flushed with hope, but who from the very nature of the case could know little or nothing of his duties at that particular place. He was practically alone in the drawing room, and did not know where to find such drawings as were required, and candor requires it to be said that he desired to ask many questions about those he did find. The superintendent unfortunately had nothing to do with his appointment, and rather resented it. So he did not trust any of his work, and the new comer was obliged to learn his practical experience at that establishment, where he was known as the mechanical engineer, by having all his work done over by the pattern maker or others, under the eye of the superintendent or master mechanic, and be subjected all the time to the jealousies and annoyances incident to such a method of introduction.

His practical experience was certainly learned under difficulties which I trust none of you may experience. This statement is made that those of you who have not yet obtained positions may not envy those who have, and that each and all of you may be careful not to take a position so far above your experience, if not your capacity, as to become unpleasantly situated in the beginning. The educational facilities you have enjoyed are of such great value in some exceptional cases that the parties thus benefited may do you an injury by leading others to expect that you will be equally valuable in performing duties which require much more practical experience and knowledge of detail than it is possible that you could have obtained in the time you have been here.

The incident is ripe with suggestions. No matter how humble a position you may take in the beginning, you will be embarrassed in much the same way as the young gentleman in question, though it is hoped in a less degree. Your course of action should be first to learn to do as you are told, no matter what you think of it. And above everything keep your eyes and ears open to obtain practical knowledge of all that is going on about you. Let nothing escape you of an engineering nature, though it has connection with the business in hand. It may be your business the next day, and if you have taken advantage of the various opportunities to know all about that particular matter in every detail, you can intelligently act in relation to it, without embarrassment to yourself and with satisfaction to your superior.

Above all, avoid conflict with the practical force of the establishment into which you are introduced. It is better, as we have at another time advised, to establish friendly relations with the workmen and practical men with whom you have to do.

You are to be spared this evening any direct references to the "conceit of learning," but you are asked and advised to bear with the _conceit of ignorance_. You will find that practical men will be jealous of you on account of your opportunities, and at the same time jealous of their own practical information and experience, and that they may take some pains to hinder rather than aid you in your attempts to actively learn the practical details of the business. The most disagreeable man about the establishment to persons like you, who perhaps goes out of his way to insult you, and yet should be respected for his age, may be one who can be of greatest use to you. Cultivate his acquaintance. A kind word will generally be the best response to an offensive remark, though gentlemanly words of resentment may be necessary when others are present. Sometimes it will be sufficient to say, "I wish a little talk with you by yourself," which will put the bystanders at a distance and enable you to mature your plans. Ascertain as soon as possible that man's tastes; what he reads and what he delights in. Approach him as if you had no resentment and talk on his favorite topic. If rebuffed, tell a pleasant story, and persist from time to time in the attempt to please, until his hardened nature relaxes and he begins to feel and perhaps speaks to others favorably of you. St. Paul has said: "For though I be free from all men, yet have I made myself servant of all that I might gain the more." This is the keynote of policy, and though in humbling yourself you control and hide your true feelings, recollect that all your faculties are given you for proper use.

We have referred to some who have acquired the happy faculty of making themselves immediately useful. This is a much more difficult matter than the words imply. If one of you should be so fortunate as to be ordered to make certain tests almost like those you have already conducted here, or to tabulate the results of tests as you have done it here, or to make inspections akin to those which have been fully explained here, there is every probability the work would be done satisfactorily in the first instance. But let a much _simpler_ case arise, for instance, if a superior hand one of you a letter with the simple instructions, "Get me the facts on that," you may be very much puzzled to know what is to be done and how to do it. It may be that the letter is a request for information in regard to certain work that was carried on in the past, in which case it will be necessary for you to hunt through old records, copy books, engineering notes, drawings, and the like, and get a list of all referring to the subject; to make an abstract of the letters and notes if they are at all complicated; and finally to lay the whole before the overworked superior in a business manner, that he largely from recollection, aided by the references and notes, can write an intelligent answer in a very brief period. The way not to do it would be to say, "Yes, sir," very promptly, go off and not more than half read the letter, do something and be back in five minutes with some question or ill-digested answer; then upon receiving a polite hint as to the method to be employed, go off and repeat the operation the next five minutes; then on receiving a short reply, in what appeared to be an unnecessary tone of voice, get a little flurried perhaps, do worse next time, and in the end feel very unpleasant without having accomplished much, and make the gentleman seeking assistance lament the difficulty in teaching young men practical work.

It is possible, on the contrary, for a young man to exceed his instructions and volunteer advice that has not been asked. If he has unfortunately gone too far for some time and been sharply spoken to, he may fail the next in not fully doing the work intended. Simply putting down a column of figures would not necessarily mean tabulating facts. The arrangement and rearrangement of the columns aid in classifying such facts, so that the results shown by them will be readily seen and a great deal of labor saved in examination. A good rule in a case of this kind is to try and find some work done by other parties of a similar nature, and thereby ascertain what is needed and expected. Reasonable questions to ascertain, where records are to be found and the kind of records accessible, are always proper if made at the proper time without interrupting an immediate train of thought; and with such information as a start, if a young man will endeavor to imagine himself in a place like that of the one who has finally to decide, and try to ascertain just what information will probably be required, then patiently go to work to find and present it in condensed shape, he from that moment really begins to be useful and his services will be rapidly appreciated. It is a good rule always to keep the memoranda obtained in accomplishing a result of this kind; so that if further information is required, the whole investigation need not be made over.

This remark suggests another line of thought. Some young men with quick perceptions get in the way at school of trusting their memories, and omit making complete notes of lectures or of the various tests illustrating their studies. This carelessness follows them into after life, and there are instances where young men, who can make certain kinds of investigations much better than their fellows, and promptly give a statement of the general nature of the results, have, when called on afterward for the details, forgotten then entirely, and their notes and memoranda, if preserved, being of little use, the labor is entirely lost. Such men necessarily have to learn more careful ways in after life. It is a good rule in this, as in the previous case, to make and copy complete records of everything in such shape that they may be convenient for reference and criticism afterward.

One of the important problems with which you will have to deal in the future is the labor question, and it is probable that your very first experience with it may be in direct antagonism with the opinions of many with whom you have heretofore been associated. It is an honor to the feelings of those who stand outside and witness this so-called struggle now in progress between capital and labor, that they believe the whole question can be settled by kindly treatment and reasonable argument. There are some cases that will yield to such treatment, and one's whole duty is not performed till all possible, reasonable, and humanitarian methods are adopted. There has been an excuse for the organization of labor, and it, to some small extent, still exists.