may be quoted. The paper which was then read occupied 30 pages of closely printed minion type, interspersed from beginning to end with mathematical formula, of a high degree of tensile strength, or, to use a more expressive synonym, they were tough. It would be a very useful investigation, and it might help in the advancement of science and general engineering knowledge, if some one would make a series of tests of the capacity of resistance of an audience to mathematical strain, and would tabulate the results, or would plot them in a graphical diagram. The investigation might be conducted somewhat in this way: the investigator would prepare a series of mathematical demonstrations of a progressive character, beginning with examples in the simple rules of arithmetic, and progressing gradually to increasingly difficult problems followed by algebraic formulæ arranged in similar order, which could be succeeded by demonstrations and elucidations in which trigonometry, calculus and other tenacious mathematical methods are employed. The "sums," formulæ and demonstrations to be numbered, and each person in the audience to be provided with a card, and after the mathematical elucidation has been inscribed on a blackboard and explained, each person to mark on his card whether he comprehended the demonstration fully, partially, or not at all. From these cards a series of what may be called moduli of comprehension could be established. That is, they would show how many persons in an audience could understand simple arithmetical proof of any proposition, how many would go wool-gathering over decimal or vulgar fractions, the proportion of people to whom algebra is as Greek is to all who know but one language and are not Grecians. It would, we feel sure, be demonstrated that only an infinitesimal number of persons in audiences, like those which assembled in the hall of the Mechanical Engineers on February 14 and 15, can comprehend an elucidation, in which the processes of calculus are employed, by merely hearing it read. If different scientific organizations would make such tests and establish what might be called factors of intelligence, they would be. a great help to those who contemplate reading papers before them in determining the limit of elas ticity of the audience before which they are to appear. If, for example, it was found that 90 per cent. of the persons who are members of the Society of Mechanical Engineers can un derstand arithmetical demonstrations, 60 can go as far as easy algebra, 40 per cent. cannot follow in trigonometry, and only 10 can keep up when an author plunges into calculus, then, obviously, the character of his paper should be determined by the number of people he desires to interest and instruct. If it is his purpose to interest his whole audience, he will, if he is wise, do as Professor Sweet did-leave out all mathematics. If he is willing to ignore the 10 per cent. who cannot follow in arithmetic, he may put a few figures in his paper, or he may disregard the 40 per cent. who are stumped" by algebra and risk a few or many formula. This train of reasoning will lead inevitably to the conclusion, that with a given audience a paper may have so much mathematics in it that it would not be worth while to read it at all, because so few or none could understand it. It would be somewhat like the aphorism of the young artist in Punch, who painted high-art pictures which no one would buy, and was asked by his uncle why he did not paint popular pictures, like the "Derby Day." The answer was that "art is for the few; the higher the art, the fewer the few; ultimately the highest art is for but one, and I am that ONE." There are papers which are evidently written for but one, and that one is the author. The question arises whether it is worth while to read such papers. They may have their use and be of very great value, but the reading of them before a miscellaneous audience is probably of no benefit to any one. It is safe to say that there were not three persons in the audience who listened to the paper which was read at the Railroad Club on the evening of February 15, or had the fortitude to hear it all, who could follow the reasoning or the demonstrations which the author had elaborated, evidently with much care and thought. The limit of elasticity of that audience was exceeded, and all who remained through the whole reading of it had a permanent mental "set," and their minds were stretched to such an extent that very few of them reacted when the tension was released. In a recent magazine article the author advises the jocular story teller, before telling a story, always to calmly put to himself the question, "Should I- A derive pleas ure from listening to this from the mouth of B-?" Authors of papers to be read before miscellaneous audi. ences should always subject themselves to a similar introspection, and should solemnly ask themselves the question, "Would I, the author, be interested or profited from hearing a paper of this kind and length from B- or any other person of equal caliber to myself?" It might not be a bad plan for committees in charge of such meetings to put some such question to the authors of papers before they are read. It would, of course, be very great folly, at the present day, for any one to underestimate the uses and value of mathematics as an instrumentality for analysis and investigation. The projector of the North River Tunnel, who testified some years ago before a commission that he thought “a knowledge of mathematics dwarfed a man's mind," has, it is true, a counterpart in a venerable protectionist in Philadelphia, who in a recent public letter expressed the opinion "that of all the institutions in the country, the college was the one which exerted the most pernicious influence." We all recognize the uses and value of mathematics, the regret of some of us being that we know so little; but a knowl. edge of it is somewhat like one's underclothing-useful and indispensable, but it is not well to display it publicly. There are few engineers worthy of the name who would build a bridge, a roof, or construct a machine without taking into account the elastic limit of the material used, and who will yet appear before an assemblage of people without giving a thought to the fact that the attention of those who listen to them is limited by laws as absolute as those which govern the strength and resistance of iron and steel. Of the value of the paper, whose form, character and length has been commented on, we will for the present at least have nothing to say. Some one has said that they always distrust a conclusion which cannot be proved in any other way excepting by mathematics. There is some reason for this distrust. Whether the conclusions which were reached by Mr. Parke are sound or not will not now be discussed. All that is intended here is to point out that such papers are unsuited for reading before audiences of the kind that assemble at the monthly meetings of the Railroad Club-and perhaps it would not be far wrong to say, or any other audiences-unless it be a very few who are well up in mathematics and are constantly using it. It would seem as though a short catechism might be framed which would be useful to those in charge of and those who intend to read papers or make addresses at technical and other meetings. It might embrace such questions as the following: Is there a limit within which an audience "may be tem. porarily acted upon with the certainty of recovering its figure"? When this limit is "overpassed," what happens? What proportion of the audience will probably understand and follow an arithmetical demonstration by merely hearing it read? how many can keep up with the algebra in the paper? and can you estimate the percentage of those who will not be vanquished by your calculus? Estimated in time, when the limit of elasticity of your audience will be reached, when will permanent set begin, how much extension may be expected, and how much will the area of your audience be reduced before rupture takes place ? In some cases-as in political meetings-it might be well to consider whether the reaction at the point of rupture may not be violent. It would seem as though a study of the laws of intellectual elasticity would have an analogous result to that which followed a knowledge of the principles of physical elasticity—in the one case mechanical structures were made safer, in the other there would be much less risk that meetings for technical discussion would fail in the purpose for which they are held, which, it may be assumed, is for the entertainment, instruction and profit of those who attend them. NEW PUBLICATIONS. HELICAL GEARS. A Practical Treatise. By a Foreman Pattern-Maker. Macmillan & Co., New York. This book gives very clear and detailed directions for the guidance of the pattern maker in laying out, constructing, and molding helical gears-that is, gears in which the acting surfaces of the teeth, instead of being parallel with the axes of the wheels, as in ordinary spur and bevel gears, are helicoids about these axes. The practical instruction is so explicit, that a pattern-maker, by carefully following it, could produce the best attainable results with very little original thought or invention on his own part. Considerable information is also given as to methods of molding these gears, and altogether the subject is placed in a clearer light, and its possibilities and difficulties more fully explained, than ever before in type. The author's claims as to the advantages of helical gears, and the more theoretical parts of the book generally, are not quite as happy as those parts relating to the actual making of the patterns. For instance, on page 4, he states that the diagonal thrust, which takes place at all points of contact situated away from the actual pitch point of cycloidal gears, is an evil inseparable from the action of ordinary gears which it is desirable to eliminate. If this is such an evil, why is it that involute teeth, in which this diagonal thrust is always present, even at the pitch point, are being so largely used in the best practice of to day, and are rapidly supplanting the cycloidal shape? Again, the statement that the driving force undergoes constant variation as the point of contact between the teeth moves away from the pitch point is very misleading, as we know that with properly shaped teeth the driving force is constant throughout the whole arc of action. The claim on page 6 that with helical teeth "the wheels would revolve by rolling contact without sliding, and thus approximate to the condition of ideal cylinders rolling by the contact of smooth peripheries," would be rather difficult to sustain. Helical gears would be used much more generally if they could be made as accurately and as cheaply as ordinary gears, and anything which tends to clear up the mystery surrounding them, or to simplify the methods of making them, or to improve their shapes and accuracy, is very desirable. This book undoubtedly has this tendency, and is a valuable addition to the literature on the subject. It will prove of interest and use to any pattern-maker or draftsman who has much to do with gearing of any description, and should be carefully studied by all who wish to make this kind, or are inclined to the belief that their use would be beneficial or profitable. HYDRAULIC TESTING-MACHINES. System of A. H. Emery, C.E. As Designed and Built by William Sellers & Co. (Incorporated), Philadelphia. This publication is a pamphlet of 14 pp., 71 × 7 in., in which the general principles of the Emery testing machine are first described; extracts from reports on the machine made to the Institution of Civil Engineers, the American Association of Mechanical Engineers, and the American Institute of Mining Engineers, are then given. The latter part of the book has the title of "Specification," but it is really a description of the construction of different types which are made by this firm. To those who are interested in the subject of testing machines, and have comparatively little knowledge of them or of the Emery machine, this part of the publication under review will seem quite too brief and lacking in lucidity. It is very doubtful whether any one, even the most skilled mechanic, could get a clear idea of the general construction of the machine from the description given. If one or more sectional drawings had been added, showing its principal parts or organs, with letters of reference, the reader would have had an image of these parts and their relation to each other which would have helped him immensely and enabled him to understand the general construction without difficulty. The pamphlet before us is illustrated with half-tone engravings of a Hydraulic Support Testing Machine of a capacity of 500,000 lbs., Horizontal Type Machines of 100,000 lbs., 200,000 lbs. and 300,000 lbs. capacity, and a Pump for Testing Machine with Adjustable Stroke. The following extract will interest the general as well as the technical reader : One of the proof' experiments by the United States Government Board was the breaking in tension of a forged iron link, 5 in. in diameter between the eyes, at a strain of 722,800 lbs., and immediately thereafter a single horse-hair seven thousandths of an inch in diameter was slowly strained, and after stretching 30 per cent., snapped under the recorded strain of 16 oz. Masses of metal were subjected to pressures of 1,000,000 lbs. in compression alternately with eggs and nutshells, and in all cases the machine operated with equal accuracy. The typographical work of this catalogue is by the wellknown J. B. Lippincott Company, and is all that could be desired. WHAT AN ENGINEER SHOULD KNOW ABOUT ELECTRICITY. By Albert L. Clough, E. E. The Mason Regulator Company, Boston, Mass. 4 × 63 in., 108 pp. The object of this book, the author says in his preface, is 'to present plainly and without the use of difficult technicalities or mathematics, to all who have to deal with electrical appliances, brief descriptions of their various forms, practical pointers on the troubles to which they are liable and their remedies, as well as general instructions for doing simple construction work, such as is often needed, as a slight extension of an already established plant.' It begins with some preliminary explanations and definitions about electricity circuits, volts, ampères, ohms, etc. Part I is on Light Current Working, and contains sections on the Battery, Circuits, Electric Bells. Burglar and Fire Alarms, Electric Gas Lighting, Dynamos. Part II is on Heavy Current Applications, and discusses Incandescent Electric Lighting, Arc Lighting, Transmission of Power, Storage Batteries, and ends with the Rules and Requirements of the Underwriters' Association with reference to the use of electric appli ances. The book is written in very simple and clear language, and is full of information for those who have the care of electric appliances. The deficiency in it seems to be that it is assumed that the novice knows more than he really does, and matters which no doubt are extremely plain to the writer are not sufficiently explained. The book is also without an index, which is an unpardonable literary sin. THE NATIONAL CAR AND LOCOMOTIVE BUILDER. This publication comes to us each month apparently undiminished in prosperity by hard times, and with no loss of interest on account of the dullness in business. The February number contains a number of very interesting articles-one on Passenger Car Construction, by Ernest Merrick, in which some new methods are described, and in which it is proposed to abandon the use of end platforms. Another article is a report on the Best Method of Securing Cylinders, Smoke-Boxes, and Frames on Locomotives, which was made to the Southern & Southwestern Railway Club. Some of the circulars of the Master Car-Builders are reprinted, and much other information is given which will interest those who are concerned in the construction or maintenance of rolling stock. One editorial article, however, is not cheerful reading. It discusses the question, "Where is the safest place on a train?" and points out with considerable minuteness of detail and show of technical knowledge when and where a traveler is most likely to have his neck or his bones broken. It is announced that the directory of railroads and railroad officers, which is so useful and convenient an appendage to this publication, has been officially corrected, and that the publisher has abandoned machine-set for hand-set type, and prognosticates a generally improved tone in business, for which we are all looking so anxiously. There is a kind of satisfied tone about the publication which implies a comfortable bank account and general prosperity. RAILROAD CAR JOURNAL. The bound volume of the Railroad Car Journal for the year 1893 comprises a very complete record of what has been done in car construction during the past year. While it is almost absolutely impossible, as all railroad men are aware, to obtain matter in regard to the car construction and car designing which bears the stamp of absolute novelty, yet the illustrations and the matter contained in the paper under review constitute a valuable record of current practice and of what has been done in the past. There are numerous working drawings which afford all the information which would be required for a duplication of the original in the shop, as well as photographs of perspective views giving an idea of the external appearance of the cars and car machinery described. The paper is neatly printed, and evidently considerable care is taken in the selection of matter and in the editing of the same, and the whole contains a deal of valuable information for car builders. AN ELEMENTARY TREATISE ON THE STEAM ENGINE, with Questions for Examination. By Randall W. McDonnell. Dublin William McGee; London: Marshall & Co. 71 X 4 in. 48 pp. The supply and demand for books on the steam-engine seem to be unlimited, and yet an editor of a technical journal is seldom puzzled more than he is when asked to recommend a book on this subject. The little volume before us, we are informed, is the work of a very young man, who has evidently tried to explain what he has learned from books and other sources, and has done it very well. It begins with an explanation of the old Newcomen's engine and then advances to Watt and to modern practice. It is obviously the work of an amateur author, but is better than many books by writers of more mature years. and rhetorically, that it is not easy to get at the significance of the illustrations or the fragments of reports accompanying them. The purpose of the publication is to show that Magnolia metal came out ahead, in some tests which were made somewhere by somebody, but neither the place where the tests were made nor the parties who made them are clear from the publication before us. KNOWLES SPECIAL CATALOGUE OF POWER PUMPS, for Paper and Pulp Mills. Knowles Steam Pump Works, 93 Liberty Street, New York. 5 x 7 in., 31 pp. The publishers say of this that it is a special catalogue of paper-maker's belt driven pumps. The following different kinds of pumps are illustrated and described by excellent engravings and clear descriptions: Vertical Triplex Boiler Feed Pump, Horizontal Single Boiler Feed Pump, Horizontal Duplex Light Service Pump, Vertical Triplex Pressure Pump for Hydraulic Pulp Grinders, Horizontal Duplex Pressure Pump for Hydraulic Pulp Grinders, Vertical Post Stuff Pump, Vertical Fly-wheel Stuff Pump, Vertical Fly-wheel Post Stuff Pump, Vertical Duplex Geared Stuff Pump, Triplex Stuff pump, Suction-box Vacuum Pump, Vacuum Pump for Revolving Suction-box, Vacuum Pump for Sulphite Process, Underwriter Fire Pump, Automatic Receiver and Pumps. The engraving, printing, and descriptions are all excellent. BALL BALANCED COMPOUND LOCOMOTIVE. 21 pp., 6 × 91 in. This pamphlet describes a form of locomotive with out. side cylinders arranged "tandem" fashion. The centers of the two low-pressure cylinders are sufficiently near together to be connected to crank pins close to the wheels. The centers of the high-pressure cylinders are farther apart, and they are connected, by separate connecting rods, to pins on return cranks attached to the main crank-pins. These two pins are set opposite to each other, so that the reciprocating parts of one cylinder balance those of the other. The trailing wheels also have return cranks, and there are two coupling-rods on each side of the engine, which is of the American type. There are also illustrations of an eight-wheeled suburban locomotive of the Forney type with the balanced compound features adapted to it. These are all very well illustrated, the engravings being made from excellent drawings, but which have been reduced too much, the dimensions being illegible. The office of the Company is at 82 Church Street, New York. AFTER THE FAIR. Twenty-fifth Anniversary Souvenir of the Page Belting Company. Concord, N. H. 6 × 9 in., 36 pp. The purpose of this pamphlet is to publish the judges' reports and awards which were made to the Page Belting Company, for leather belting exhibited at the Columbian Exhibition, and also to illustrate and describe their exhibits at the great" show." The first few pages are devoted to the awards and reports, and to Corroboratory Testimony" of those awards. This testimony consists of a series of letters from the parties who used the Page belting at the Exhibition. These are followed by a series of half-tone engravings showing the various exhibits of the Company with descriptions thereof. There is also a history of the Company with a view of their original shops of 1868, and of their present works at Concord, N. H. The last page contains views of their warehouses at 91 Liberty Street, New York; 31 Pearl Street, Boston; 165 Lake Street, Chicago, and 42 Sacramento Street, San Francisco. On the last outside cover is a diagram showing a whole hide of leather, and descriptions of how it is cut to make different kinds of belting. WHEELER'S IMPROVED SURFACE. CONDENSERS. Wheeler Con denser & Engineering Company, New York. 9 × 54 in., 20 pp. The outside cover of this publication has an excellent engraving showing a section of the Wheeler Surface Condenser. It is printed in three colors, the outlines being black; the brass parts are shown in yellow, and the iron or steel parts in blue. The introductory part of the pamphlet sets forth the "Advantages" of the condenser, and says that when there is a sufficient supply of water available, any existing high-pressure engine can readily be converted into a condensing engine with a resulting economy of from 15 to 25 per cent. of fuel. A description of the construction and operation of the condenser and of the improved "Wheeler Admiralty Tube," which is used, follows. This is succeeded by excellent wood-engravings, showing perspective and sectional views of different kinds of surface condensers made by this Company. An illustration of a jet condenser, a view of their works at Carteret, N. J., completes this pleasing and satisfactory publication. It may be added that the New York office of the Company is at Nos. 39-41 Cortlandt Street. HYATT ROLLER BEARING COMPANY. 12 pp., 5 X 9 in. Roller bearings have been the subject of the dreams of innumerable inventors for a great many years past. In the pamphlet before us it is said that more than 300 patents have been issued in this country on such bearings, and yet comparatively few are now in use, and those only under slow-moving mechanism. Roller bearings which have heretofore been made had to be turned, hardened and accurately finished. The same is true of ball bearings. The Hyatt bearing is an ingenious device to get over the difficulties encountered in other similar bearings, and consists of flexible bearings. They are made of a ribbon or flat bar of steel wound on a mandrel to form a close spiral, and it is claimed that "such a roller adapts itself perfectly to every inequality of the axle or the bearing, and cannot be crushed or distorted by side strains on the bearing or bending of the journal." It is also said that such bearings do not require to be turned or finished in any way, and are therefore much cheaper than any other roller or ball bearings which have heretofore been proposed. The idea is a very ingenious one, and has in it a promise of great success. Various forms and applications of the bearings are well illustrated and described in the pamphlet which has been issued by the Company, whose office is at 77 Liberty Street, New York. The THE HISTORY OF A LEAD-PENCIL. By Walter Day. Joseph Dixon Crucible Company, Jersey City, N. J. 64 × 51 in., 16 pp. Probably of the millions of people who daily use lead-pencils very few have any idea of how or where they are made. The little publication which the Dixon Crucible Company has just issued gives a great deal of interesting information about the different kinds of pencils which they make, how they are manufactured, and why. The pamphlet is as interesting as a good novel, and probably few who have the time to read it will lay it down without finishing it. The first part of the description, however, has a sort of strident personal flavor, which may have somewhat the same effect on its readers that those people have who take the liberty of slapping us on the back or punching us with their sticks or umbrellas. The author has taken liberties with the reader which are not entirely agreeable. He begins with the imperious command, printed in caps, "TAKE THAT PENCIL OUT OF YOUR POCKET. It would not be pleasant to have a stranger say that to us, nor is it pleasant to read. The first person singular occurs oftener, too, than is agreeable. Barring these slight lapses of good taste, this little history is very pleasant and profitable reading. It is well illustrated with excellent wood cuts of the mines, mills, and works of the Company, a portrait of its founder, various kinds of pencils made by it, and finally a view on Crystal River, Fla., showing the rafting of cedar logs to the Dixon mill, with a fine alligator in the foreground, who evidently is not happy because he is not provided with a Dixon pencil. OUR SHARE IN COAST DEFENSE-Part II. Builders' Iron Foundry, Providence, R. I. 55 pp., 6 × 9 in. In the brief preface to this pamphlet the publishers say that, "In publishing the pamphlet Our Share in Coast Defense-Part I,' we gave in popular form a rather brief description of the 12-in. Breech-Loading Rifled Mortars and the methods which we employ in their manufacture. We now supplement that pamphlet by reprinting extracts from Government Specifications and Inspectors' Reports, believing that more complete descriptions, exact particulars, and minute details will interest mechanical engineers and others who follow advanced foundry and machine-shop practice." The frontispiece is a half-tone engraving, showing the 12-in. breech-loading rifled mortars, which was published in THE AMERICAN ENGINEER of last September. This is followed by specifications of their manufacture, with illustrations of the form and position from which test pieces are taken. An outline engraving and outside dimensions and another sectional view of one of the mortars is then given, with specifications governing the finishing and assembling thereof. Other interior views in the foundry are also given, with an outline view of an old style 13-in. seacoast mortar. The metal which is used and the process of manufacture is described, and reports of tests of the materials used are given. A description of the method of operating the breech mechanism, with illustrations of it, completes the work. It is all written in a popular way, and will interest all who are concerned in the subject which it discusses. An omission to be noted is the absence of titles to most of the engravings. A very large proportion of the people into whose hands any book falls never go further than to look it through. To such proper titles to engravings are a great help. "And in daytime, midst his dreaming, Peering through his frosted window, While his feet are warm, and legs, too, Dangling limp against the pipe-ways." The last line of our quotation, it will be seen, does not even up" quite right. The following amendment is therefore suggested: While his feet are warm, and legs, too, Seriously, we think the Consolidated Car-Heating Company's system of heating is better than Mr. Cunningham's poetry, and, by means of the Sewall Steam Coupler, the lines of pipe on the cars are connected together more satisfactorily than some of the lines of the poetry are. Still, there are some strokes of genius in the poem. For example, the following line addressed to the locomotive : Bureau of the American Republics. Monthly Bulletin, December, 1893. The Political Economy of Natural Law. By Henry Wood. Boston Lee & Shepard. Sixth Annual Report of the Board of Mediation and Arbitration of the State of New York. Albany: James B. Lyon, State Printer. Rules for Operation of Steam Heating Systems, Baker Heater, and Pintsch Gas. Published by the Baltimore & Ohio Railroad Company. Consular Reports. January, 1894: Commerce, Manufactures, etc. (Packing Goods for Export.) Washington: Gov. ernment Printing Office. The National Geographic Magazine, January 31, 1894: Proceedings of the International Geographic Conference in Chicago, July 27, 28, 1893. Washington: Published by the National Geographic Society. Immigration and Passenger Movement at Ports of the United States during the Year ending June 30, 1893. Report of the Chief of the Bureau of Statistics. Washington: Government Printing Office. 64 pp., 9 x 5 in. The Foreign Commerce and Navigation of the United States for the Year ending June 30, 1893. Prepared by the Chief of the Bureau of Statistics of the Treasury Department. Washington Government Printing Office. 670 pp., 114 × 8 in. Engineering Education, being the Proceedings of Section E of the World's Engineering Congress held in Chicago, Ill., July 31 to August 5, 1893. Published by the Society for the Promotion of Engineering Education as Volume 1. of their Proceedings. Edited by De Volson Wood, Ira O. Baker, J. B. Johnson, Committee. Columbia, Mo.: E. W. Stephens, Printer. (This volume is to be had of Professor J. B. Johnson, Secretary, Washington University, St. Louis; $2.50.) SAVING EFFECTED BY COMPOUND LOCOMOTIVES. Editor of the AMERICAN ENGINEER AND RAILROAD JOURNAL : Apropos of a recent discussion relative to the merits of the compound locomotive, I am now able, fortunately, to give you some data relative to the action of a compound locomotive on the Chicago, Burlington & Quincy Railroad, which, I think, will be of interest. The data was gathered, not to determine the merits of the compound locomotive, but because the general officers thought the coal record for a certain month was too high on the division on which the compound was running, so that the report contained the fuel record of the compound. The fuel used by each engine and the number of loaded cars hauled was looked up for each engine. The results are stated in the number of pounds of coal burned in hauling one loaded car 1 mile. The record for the compound was 3.27 lbs. of coal per loaded car mile. The best record for any simple engine of the same class was 3.85 lbs.; for the poorest, 6.32 lbs.; for the average of 40 engines, including the compound, 4.61. So that the saving made by the compound was as follows: Over the best record of any other engine in the same class, 15 per cent.; over the poorest record of a simple engine, 52 per cent.; over the average record of 40 engines of the same class, 29 per cent. the compound runs in the pool with all the other engines, as the record covers the period of a month, and is almost a duplicate of a similar record made when the engine was new, it seems to me there is no escape from the conclusion that this compound, at least, is saving us at least 25 per cent. C. H. QUEREAU, Engineer of Tests. MARINE NOTES. As Japanese Torpedo-boats. Seventeen torpedo-boats are now in course of construction at the navy yard at Kobe, Japan. The Chinese Navy Worthless.-It is stated at Shanghai, on excellent authority," that the real reason why none of the Chinese squadron went to Bangkok was that it was found there was not one of the squadron prepared for such a voyage without refitting, the internal condition of the ironclads and cruisers of China's new navy being very imperfect.-London Daily News. The Loss of the "Kearsarge."-The old corvette Kearsarge, of the United States Navy, was foundered on Roncador on the night of February 2. She is one of the two vessels, the Hartford being the other, which, by special act of Congress, was to have been kept in commission. Her principal victory, for which she is noted, was the destruction of the EnglishConfederate cruiser Alabama, off the coast of France, during our late Civil War. A Commerce Destroyer.-Sir E. J. Reed, speaking recently at a banquet at Cardiff, said that "he was concerned at the present moment in the construction of a foreign cruiser, a vessel without any armor at all, and without any pretension to be anything but a very fast vessel built for the purpose of causing what mischief she could under certain conditions. He had no hesitation in saying that every one of the guns she carried could penetrate the unarmored ends of 10 of the British line-of battleships, which, being so penetrated, must sink. The Cruiser "Olympia."-The report of the trial board on the speed of the new cruiser Olympia, which was run in the Santa Barbara Channel off the coast of California, gives the vessel a speed of 21.686 knots, which means a premium of $300,000 to the builders. In every point of machinery, speed, H.P., and coal consumption the plans and specifications have been beaten. The required pressure test was 160 lbs., that carried was 166.53; at the starboard engines steam-chest the register was 166.75; at the port engines, 164.83. The Cruiser "Montgomery."-The trial of the cruiser Montgomery, which was held off New London, in Long Island Sound, shows that the vessel developed a speed of 19.056 knots. Her contract called for a speed of 17 knots, and this will mean a bonus of $200,000 to the builders, the Government paying $25,000 for each quarter knot in excess of the contract speed. The average revolution of the port engines during the trial were 180.7, and of the starboard engine 180.3; the average steam pressure 160 lbs. On a requirement of 16,000, the main engine's indicated H.P. was as follows: Starboard, H.P. 2.001; first I.P. 3,097.3; L.P. 3,198.5; total, 8,297.6; port, H.P. 1,903.2; first I.P. 3,185.6; L.P. 3,463.4; total, 8,552.2; grand total for main engines, 16,849.8. The collective H.P. of the main and auxiliary engines operated during the trial amounted to 17,313.08. It will take from seven to eight months to put the finishing touches on the Olpmpia so that she can be declared in commission. Life-Saving Kites.-We called attention in our issue for September, 1893, to the experiments of Professor G. Woodbridge Davis, in sending a life-line ashore from the Brenton Reef lightship. These experiments have been followed up by others at Sandy Hook, which were equally successful. The kite used is foldable; the sticks are of light ash revolving upon a common center axle, and the frame is covered with oiled muslin. Instead of a single line leading from the face of the kite, two lines are employed, one from either side, and by checking one or the other a trifle after the kite has been raised, it may be directed four compass points or 45° from its direct leeward course, so that it may be landed anywhere within an area of 90. The value of this steering property may be appreciated when it is explained that it often happens that the only near land to a wrecked vessel is not directly to the leeward, but to the right or left of that point. The principle of the steering action of the kite is based upon that of the foreand-aft sail, which may be trimmed to a certain limit without spilling the wind. As soon as the kite is raised and the guy. lines adjusted so that it is directed aright, these are secured to a wooden float or buoy, and the latter is thrown overboard, having to it a light but strong line which is paid out as the kite flies to the land, dragging the buoy through the water. When the float reaches the beach the life saving crew detach it and bend on to the ship's rope the regular lines and blocks, which the wrecked seamen haul out to their vessel and make secure, according to the directions found painted on the small wooden tags fastened to the blocks. The crew are then brought to land either in the breeches-buoy or life-car hauled out to them by the life-saving crew. THE BATTLESHIP "TEXAS." THE battleship Texas, which is now nearing completion at the United States Navy Yard, at Norfolk, Va., will be one of the most powerful battleships of the new Navy. It is a twinscrew vessel of the belted type, built after the designs of the Barrows Ship Building Company. It has a belt of armor admidships to protect the vital portions of the ship, as well as under-water decks from the ends of the armor to the extremities of the vessel. Her dimensions are: Length between perpendiculars, 290 ft.; extreme breadth, 64 ft. 1 in.; molded depth to upper deck, 39 ft. 8 in.; draft of water forward, 22 ft.; draft of water aft, 25 ft. 5 in.; giving a mean draft of 22 ft. 6 in. The displacement when brought down to this draft is 6,300 tons, and the transverse meta-center of gravity is calculated at 3 ft. 1 in. The longitudinal meta-center above the center of gravity is estimated at 237 ft. When being loaded the vessel drops 1 in. for each additional 30 tons, and the moment required to change the trim 1 in. in 1 ft. is 432 tons. The engines, which we will illustrate in a later issue, were built by the Richmond Locomotive Works, at Richmond, Va., from designs approved by the Navy Department, and have an indicated H.P. of 8,600. As the vessel is intended purely as a fighting machine, no attempt has been made to give her the excessive speed which has been attained by the cruisers Columbia and New York; therefore her maximum speed is 17 knots, and she will be given a complement of 300 officers and men. Referring to our cross-sectional engraving, the vertical keel is made of steel 20 lbs. to the square foot, and reduced to 11 lbs. at the ends. It is 39 in. deep amidships, with double angles at the tube of 3 X 3 in., weighing 8 lbs. to the foot. The outer flat keel weighs 25 lbs. per square foot, and the inner 17 lbs. to the square foot. From the fourth longitudinal to the armament shelf, the outer and inner angles are 3 × 3 in. with a plate between lightened with holes. The frames both before and abaft the armor both consist of Z bars 6 × 34 × 3 in., weighing 15 lbs. to the foot, with the lower ends where they come down on the armor deck secured by 15-lb. plates, |