Scientific American Supplement, No. 711 | Page 7

keel to the front and rear. The weight of the barrel of the gun is each six tons, that of the steel shells 51 kilogrammes, that of the charge 22 kilogrammes; initial velocity, 610 meters.
The 11 quick-firing guns are partly placed along the broadsides, partly in the masts, of which there are two. The triple expansion engines, having each a bronze screw of 4.42 meters diameter, with three blades and a rise of 6.3 meters, make with natural draught 105 revolutions, and with forced draught 120. The pumping apparatus are able to lift in one hour 400 tons of water. The front boiler room contains a special cylindrical boiler for the working of the electrical apparatus, for hydraulic pumps of the artillery service, for anchor windlasses, ventilators, fire engines, etc. The whole engines weigh 890 tons. The bunkers have a capacity for 660 tons of coal, which allows for a run of 4,500 sea miles.
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CLARK'S GYROSCOPIC TORPEDOES.
Figs. 1 and 2 represent, upon a scale of about 1/10, two types of torpedoes, the greatest number possible of the parts of which are made revolvable, so as to render the torpedoes as dirigible as the gyrating motion permits of.
Fig. 1 represents an electric torpedo actuated by accumulators, A A, keyed upon the shaft, and revolving along with the gearings. At the beginning of the running, the accumulators are not all coupled, but under the action of a clockwork movement which is set in motion at the moment of starting, metallic brushes descend one after another upon the collectors, B, and set in action new batteries for keeping constant or, if need be, accelerating the speed at the end of the travel.
[Illustration: Fig. 1.]
[Illustration: Fig. 2. CLARK'S GYROSCOPIC TORPEDOES.]
Fig. 2 represents an air torpedo proposed by the same inventor. The air reservoir, C, revolves along with the gearings under the action of the pneumatic machine, D. The central shaft is hollow, so as to serve as a conduit. The admission of air into the slide valve of the machine is regulated by a clockwork which actuates a slide in an aperture whose form and dimensions are so calculated that the speed remains as constant as possible toward the end of the travel.
The trajectory of the two torpedoes is regulated by a cylindrical bellows, F, which gives entrance to the sea water. The springs shown in the figure balance the hydraulic pressure. The tension of these springs is regulated by the rod, H, according to the indications of the scale of depths, I.
When the torpedo reaches too great a depth, the action of the springs can no longer balance the increase of the hydraulic pressure, and the accumulation of the charge in the rear causes the front to rise toward the surface. When the torpedo reaches the surface, a contrary action is produced.--_Revue Industrielle._
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THE FIRST STEAMBOAT ON THE SEINE.
[Illustration: FIRST STEAMBOAT BUILT ON THE SEINE.]
The accompanying engraving represents the remarkable steamboat that the unfortunate Marquis de Jouffroy constructed at Paris in 1816, after organizing a company for the carriage of passengers on the Seine. De Jouffroy, as well known, made the first experiment in steam navigation at Lyons in 1783, but the inventor's genius was not recognized, and he met with nothing but deception and hostility. With the obstinacy of men of conviction, he did not cease to prosecute his task. He assuredly had an inkling of the future in store for the invention that he was offering to humanity.
The paddle wheel boat that he constructed at Paris in 1816 did not succeed any better than its predecessors; it was remarkable nevertheless in appearance and structure.
The engine was forward, as shown in the engraving, which is copied from a composition of Dubucourt's.
The company organized by the marquis was ruined, and, as well known, the unfortunate inventor himself died in poverty in 1832, at the age of eighty-one years.--_La Nature._
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THE ELECTRIC MOTOR TESTS ON THE NEW YORK ELEVATED RAILROAD.
The American Institute of Electrical Engineers at its last meeting of the season, held June 25, again considered the subject of electrical traction, the paper presented by Mr. Leo Daft being based upon some recent electrical work on the elevated railroads and its bearing on the rapid transit problem. The Railroad Gazette gives the following abstract:
He introduced the subject with a tribute to the efficiency of the elevated railroad system as it is now operated by steam, with special reference to that section of it known as the Ninth Avenue line, upon which his experiments with the electric motor have been conducted, over which passengers are now conveyed a distance of five miles in 26 minutes for five cents, which he considered the best and cheapest municipal rapid transit in the world, and which is