be developed, as rapidly and as exten- tools, there are instruments of the greatsively, as the means placed at the dis- est accuracy consisting of standard surposal of the Trustees of the University, face-plates, straight-edges, and squares of and a demand for advanced and complete various sizes; a standard measuring macourses of instruction, shall allow. The chine reading to the ten-thousandth of an courses now ready will be supplemented inch, a universal grinding machine for by other and more advanced courses, producing true cylindrical and conical from time to time, as the number of stu- forms, and a set of Betts' standard dents applying for advanced instruction gauges. shall justify further exp nsion; and it is The smithy contains ten forges of the hoped and anticipated that, in time, the most approved pattern, and correspondcollege may embrace schools of every ing outfits of smiths' tools. The instrucbranch of mechanic arts, and of mechan- tion embraces forging, welding, temperical engineering, which may assume ing, etc. prominence in connection with the development of the great industries of the country. Its buildings and equipments are already extensive and remarkably well adapted to the work to be done.

The foundry is equipped for giving thorough instruction in loam and sand moulding, and the casting of iron and brass. The cupola for melting iron is a Colliau's improved, with a capacity of one ton per hour. There are also a crucible furnace for melting brass, a core oven, a rattler, and the other usual foundry appliances.

The buildings of Sibley College have been erected and presented to the University by the Hon. Hiram Sibley, of Rochester, N. Y., to whose intelligent and patriotic liberality the University is The mechanical laboratory is supplied also indebted for the workshops, tools, with several kinds of testing machines, and nearly all of the illustrative appar including those made by Fairbanks & atus. The Sibley professorship of Prac- Co., for tests of beams; by Riehle Brothtical Mechanics and Machine Construc-ers, for rapid work in tests by tension; tion is sustained by an endowment, which by Olsen & Co.. for slower, but more preis another of the gifts of the same friend of the University.

cise, work in determining, especially, the elastic properties, and the modulus of The main building of Sibley College is elasticity of materials; and by the Pratt constructed of stone, and is 160 feet in & Whitney Co., the latter being_an length and 40 in breadth, and three Autographic Rec rding Testing Mastories in height. It contains the lecturerooms, drawing rooms, and museums of the college, and is connected with a series of workshops, including a wood shop, machine shop, forge, foundry, and mechanical laboratory, with rooms devoted to various other purposes, and with the janitor's house.

chine," used in making special investigations of the properties of the materials used in construction. A Brown and Sharpe machine, for testing the strength and ductility of fibrous materials, completes the list of testing machines. Other machines are used, in the course of laboratory instruction, for determining the The wood-working shop is supplied value of lubricants, their endurance unwith all needed hand and power tools, der work, and their coefficients of fricwork-benches, and accessories sufficient tion. Dynamometers will be brought for sections of classes up to twenty-five into use in measuring the power of primeor more in number, should it be found movers, and the work done in driving advisable to work so many together. machinery. Steam-engine indicators, of The machine shop is supplied with which all the most familiar kinds are replathes of various kinds, planers, grind-resented in the collections, are applied ing, drilling, and shaping machines, a to testing steam-engines, and other universal milling machine fitted for cut- heat motors; and steam gauges, counting plane, bevel and spiral gears, spiral ters, and other minor kinds of testing cutters, and twist drills, with additional apparatus, and instruments of exact tools and attachments for graduating measurement, are made, in various ways, scales and circles and for working various to illustrate the course of instruction in forms and shapes. this line of work. The test trials of In addition to the usual hand and lathe steam-boilers, and the testing of other

apparatus and machines, to determine have been chosen from among the most their capacity, efficiency, and adaptation distinguished men of the profession. to their intended purposes of applica- These gentlemen choose their own subtion, form part of this course, and the jects, and times of lectures, and their own needed apparatus is provided here as re- method of presentation of the subject quired. The collection of mechanical selected. They will, in some cases, delaboratory apparatus in these departments is already exceptionally rich and complete, and is expected to be steadily increased by annual accessions by purchase and gift from members of the pro fession and others interested in this branch of technical education.

liver formal lectures, in others open the regular debates in the lyceum, in others give interesting talks to the classes in the lecture rooms, in connection with the work which may be then in hand. In the debates, in which the students are expected to take part freely, the discussion will take such direction as those present may find most attractive and profitable. The formal lectures may, or may not, be followed by debate, as may, at the time seem, in the opinion of the lecturer and of the director, best.

The museums of Sibley College contain the Reuleaux collection, illustrating the course of instruction in mechanism; a very interesting collection of other apparatus having a similar use; various forms of steam-engine governors; models illustrating the forms of parts of ma- The preceding account of Sibley Colchines, and of complete constructions; a lege represents the present condition of large variety of machinery, such as is seen the institution, and the form of its courses in the market, contributed, in most cases, of instruction, and indicates what is by the makers; and many objects which the intent of the Trustees and of the officannot be so well classified, which are, how-cers of the University, and of Sibley Colever, all of interest to the student of ma lege, in regard to its position and develchinery. The drawing rooms are care- opment. As experience may yield sugfully fitted up with a view to convenience gestions, and may throw more light upon and efficiency of work in instruction, and the possible future of the college, the are supplied with all the instruments, plans here outlined will be subject to models, casts, and other material needed. modification, and, it is hoped, to continuStudents are also expected to make free ous improvement. The announcement use of the collections in the museums, here made is, to that extent, provisional. and to sketch in the workshops, as they It is, however, the full intention of the acquire expertness in the handling of in- Trustees to endeavor to carry out the destruments, and power in the use of the sires of the Founder, and the policy of hand. The lecture rooms are fitted up, the University, as defined by its charter, each with a view to the work to be done, in such manner as shall secure to stuand contain cases of apparatus and mod-dents entering this institution opportuniels, drawings, wall charts, and samples ties of study, and of acquiring a knowlof materials in use in the arts and trades, edge of the facts and principles, and of all so arranged that the instructor may bring them before the class with least possible loss of time, or expenditure of labor.

A lyceum is also fitted up, for the use of students who are enrolled in the association to which it is assigned, in which weekly debates are carried on, and in which the working library of the depart ment may be gathered.

Supplementing the regular course of instruction, a series of lectures will be delivered in the lyceum and in lecture rooms, irom time to time, by members of a body of “Non-Resident Lecturers," who

the practice, of mechanical engineering, in whatever branch they may desire to work, such as can nowhere else be excelled, and to promote the growth of the schools of engineering and mechanic arts constantly, rapidly, and healthfully, so as to secure, in their operation, an efficient means of promoting every great industry of the country, while giving to every citizen the means of educating his children in the most useful and desirable directions.

The Director of Silby College is Professor Robert H. Thurston, late of Stevens Institute of Technology.

AN ORIENTAL CANTILEVER BRIDGE.

A LETTER from Yokohama, Japan, bear- granite, octagonal, monolithic, mortised ing date October 6th, gives the follow- for stone girders; monolithic plate beam ing description of an old bridge con- to receive wooden superstructure. The structed by native engineers. The cut stringers are fastened into the abutherewith presented was prepared from a ments, balance over the stone beam, but photograph enclosed in the letter. do not reach, by considerable distance, the gap being fitted by middle stringers

The writer evidently shared the popu

lar but erroneous impression that engineers had urged the claim of novelty in the cantilever principle.

The following is the description verbatim:

let into the shore stringers.

"The Niagara Bridge is a mere amplification of this one, built before America was settled, as a religious duty, very expensive, of thick, red lacquered work, "At the Sacred City of Nikko, the and, like a bridge of angels, its planks are other day, I was rather amused and in- never profaned by the feet of the laity. terested at seeing a fine and very costly But it seems queer-like, to come away bridge of cantilever construction-abut- here to find our new inventions very ments of hewn stone, shore piers hewn old."

FARADAY is said to have estimated that the park. There was but one flash of there was no more electrical work in a lightning, which, singling out two fine lightning flash than would decompose a oak trees, completely destroyed the top drop of water. It must take much more portion of one and shattered to pieces electricity, if this is true, to decompose a the solid base of the other, depositing drop of water than to do a vastly heavier the immense upper part, neatly severed amount of work. Mr. W. Bellasis writes and intact, some feet away. The explofrom Roehampton, August 30: "In case sion must have been terrific, as trees close it has escaped notice, an opportunity now by are damaged by the large splinters offers of witnessing in Richmond Park a which, dried up and sapless, lie about in truly awful spectacle. On the 6th a storm, all directions." scarcely observed elsewhere, burst upon

PHYSIOGRAPHY.

BY JOHN EVANS, Assoc. Inst. C. E.

A Lecture delivered before the Institution of Civil Engineers.

THE Council of the Institution of Civil The water which we consume for our Engineers having determined on the de- daily use is usually derived from one of livery of a course of lectures on the three sources-springs, streams, rivers Theory and Practice of Hydromechanics or lakes, or reservoirs of some kind in have done me the honor of requesting which the rainfall is artifically stored. me to give the first of these lectures, and In all cases, however, the water comes to have suggested "Physiography" as my us more or less immediately from the subject. At the time that I expressed clouds, and they in turn are fed by my willingness to comply with this re-evaporation from different parts of the quest, I hoped that I should be able to surface of the globe. The principal find sufficient spare hours to do some source whence the air derives its moistjustice to the subject, but, unfortunately, ure is no doubt the ocean, from and toowing to the absence of the President of the Royal Society, unexpected duties have devolved upon me, and the small modicum of leisure which my ordinary avocations allow me has been considerably cut down. I must, therefore, beg for some indulgence if in the following remarks I seem to treat my subject in an inadequate manner, and do not in some respects enter into the amount of detail which might not unreasonably have been expected.

ward which there is a constant circulation of water. As was said by the wise man of old: *"All the rivers run into the sea, yet the sea is not full; unto the place from whence the rivers come, thither they return again."

The air, then, is the great conductor of moisture from the sea and other sources to the springs and streamlets which feed the rivers, and the term "atmosphere"-the sphere of vaporBut what is my subject? The word fittingly describes under one of its most "Physiography "-for which as a title to beneficent functions the attenuated fluid my lecture I must deny all personal re which envelops our globe. I need hardly sponsibility-is one of very wide import, enter into the chemical nature of water, and has been defined in the dictionaries which consists of oxygen and hydrogen as meaning "a description of nature, or in the proportion of one to two, nor into the science of natural objects." I shall that of air, which is, in fact, a mixture of not attempt to accept the word in this about one part of oxygen-gas, with about wide sense, or the limits of one, or even four of nitrogen. To speak accurately, if of a dozen lectures, would not suffice for we take 100 cubic feet of pure air, they the treatment of the subject. And, more will consist of 20.9 feet oxygen and 79.1 over, it has already been admirably feet of nitrogen. If, on the other hand, worked out by Professor Huxley in his we take 100 lbs. of pure air, it will be course of lectures at the London Institu- found that they consist of about 23 lbs. tion, which have been expanded into a of oxygen and 77 lbs. of nitrogen. Air, most instructive volume, with the title however, as a rule, is not absolutely pure, "Physiography," a work which I have but usually contains about four parts in found of some service in preparing for the one thousand of carbonic-acid gas, as this evening. What I hope to do, is to well as smaller proportions of ammonia, bring before you such portions only of hydrogen and nitric acid. These may all this great subject as bear more especially have some slight effect on water falling on the supply of that indispensable ne- through the air, but in considering the cessary of life with which in various ways air as an absorbent of aqueous vapor, the lecturers who follow after me will the minor constituents may be entirely have to deal, and I must, moreover, limit disregarded. Practically, the air is never myself, as far as possible, to the phases free from this aqueous vapor, for, howof nature which may be observed in our

own country.

VOL. XXXIV.-No. 1-3

* Ecclesiastes i. 7.

:

ever dry it may appear, yet, when tested gated the subject. From shallow vessels by powerful absorbents of moisture, at Plaistow, and from a larger surface of water is constantly found present. The water at Lea Bridge, the annual evaporahotter the air the more capable it is of tion was about 21 inches per annum, and, absorbing moisture and holding it in in- as might be expected, the quantity varied visible suspension, we might almost say in at different seasons of the year. Speaksolution. On the coldest day, however, ing roughly, it was about as follows:the air retains some power of absorbing January to March, 4 inches; April to moisture, and will even carry it off from May, 8 inches; June to September, 7 snow or from a lump of ice. As water inches; October to December, 2 inches. itself, under ordinary circumstances, is At Dijon, about 26 inches were carried converted into steam at a temperature of off from the surface of large vessels of about 212° Fahrenheit, it is evident that water. Extensive observations made in with air at this or a higher temperature Denmark show about 28 inches from an invisible admixture of air and water water, 30 inches from short grass, and might exist in almost any proportions. 44 inches from long grass. For it must be borne in mind that the In hotter regions the evaporation must ordinary conception of steam being visi- be greater still; and I may just refer to ble is entirely erroneous. It is not until the Dead Sea, into which the river Jorit has to some extent been condensed and dan is constantly flowing, and which, reduced into small particles of water that notwithstanding, is kept by evaporation steam assumes a visible consistence. If, at a level of more than 1,300 feet below on a bright day, we watch the steam that of the Mediterranean. Even the blowing off from the safety-valve of a Mediterranean itself affords another inlocomotive engine, we can observe three phases. Close to the valve there is little or no appearance of vapor, next we can observe volumes, in fact clouds, of visible steam being gradually formed, and as these are wafted away in feathery streaks by the wind they gradually disappear, the vapor having been absorbed and incorporated in the air, to be again deposited in the form of a visible cloud and eventually of rain at some future and possibly long distant time.

stance of the wonderful power of the sun; for, notwithstanding the volume of water poured into it and the inland seas connected with it by the large rivers, such as the Rhone, the Po, the Danube, the Dnieper, the Don, and the Nile, this accession to its waters appears to be insufficient to keep pace with the evaporation from its surface, as notwithstanding occasional outward undercurrents, there is almost constant inset of the current through the Straits of Gibraltar. At The quantity of moisture present in Madras, it has been found that there is the air varies considerably in different an annual evaporation of about 90 inches; countries and at different seasons. Here, and from a reservoir at Nagpoor, evaporin England, it is said that the aver- ation went on at the rate of one-fifth of an age proportion of water present in inch per diem, so that 48 inches disapthe air is about 14 per cent. When peared in the course of two hundred and the air at an ordinary temperature forty days. At Dublin, on the average is nearly saturated, a slight reduction of of two years, Dr. Haughton found that heat suffices to make the moisture visible. the evaporation fell short of the rainfall How often do we not observe a mist ris- by only 1 inch. In fact, Mr. R. H. Scott ing, as it is called, towards sunset, after thinks that in nearly all parts of the a bright warm day; and how often have globe, the evaporation from a free water we not seen the morning's mist, and even surface is on the average about equal to the clouds at a higher level, gradually the rainfall. The effect of wind is largely disappear under the genial influence of to increase the evaporation, and the hot the sun's rays.

The power of the air to carry off vapor has been put to the test by various experimental researches. In our own country, Howard, at Plaistow; Greaves, at Lea Bridge; Laws and Gilbert, at Rothamstead, and others, have investi

I winds of the equatorial regions, acting on the surface of a warm sea, become highly charged with vapor. It is, indeed, mainly from the surface of the ocean that the supply of aqueous vapor in the atmosphere must be derived. The fine warm weather which dries up a land surface un