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by Dr. R. J. Gatling, of Indiana, in 1861. It has from five to ten barrels, each barrel having a corresponding lock. Al


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breech is closed when the discharge occurs; while through the agency of the backward motion, the empty cartridge



backward action. By means of the forward motion, the cartridges are placed in the chambers of the barrels, and the

cases are extracted. The gun is fed by feed cases, which are made to fit in a hopper communicating with the chambers. Continuous firing can be carried on by the ten-barrel gun at the rate of 1,000 shots a minute, as one case is replaced by another as fast as it is emptied. The five-barrel gun weighs 100 pounds." It is mounted on a tripod, and can be fired at the rate of 800 shots per minute. The bore of each barrel extends from end to end; and the breech is chambered to receive a flanged "center-fire" metalliccase cartridge. The breech ends of all the barrels are screwed into a disc, called the "rear barrel-plate," which is fastened to the central shaft; the muzzles pass through another disc, called the "front barrel-plate," on the same shaft. A hollow metal cylinder is fastened upon an extension of the central shaft, and is called the "carrier-block," behind which the shaft carries another cylinder, because each lock is acted on by a spiral spring operating the hammer by which the charge is fired. The shaft, the group of barrels, the carrier-block, and the lock cylinder, being all connected, revolve together; this revolution is effected by a toothed wheel, which is fastened to


the shaft, and which is worked by an endless screw on a small axle placed at right angles to the shaft and furnished outside with a hand crank. When the lock cylinder revolves, it carries the locks around with it, and gives them a longitudinal, reciprocal motion by their rear ends slid


ing along a groove in the inclined surface of the stationary spiral cam, so that the several locks in succession are forwarded toward their respective barrels. The Gatling gun is elevated and lowered like an ordinary field gun. The effects of its fire are invariably demoralizing.

Gatling guns deserve the credit for the American victory in the charge at San Juan Hill-a fact that is not generally known. There, in spite of the absence of gunners, of spare parts, and of tools, Lieutenant Parker, by the aid of four Gatlings, seized the position of San Juan in 81⁄2 minutes-a position that was regarded as impregnable. He repulsed two counter-attacks by the Spaniards, silenced a five-inch gun at a distance of 2,000 yards, by firing on its cannoneers with a single machine gun. During the siege

of Santiago the Gatlings again repulsed sorties and night attacks.

All the important powers of the world now have machine guns. Among the more noted of them, besides the Gatling gun, are the Maxim, the Vickers-Maxim, the Hotchkiss, the Skoda, the Gardner,


the Nordenfeldt, the Maxim-Nordenfeldt, the Martigny, and the Pratt-Whitney. All are copied after the Gatling, and are operated on the same principle. China and Japan are well supplied with Maxims and Hotchkiss guns. The regular Chinese troops are armed with Gatlings. The Wire-Tube Gun

The very newest American war invention is the Brown wire-tube gun. The first one of these has just been built at Reading, Pa. It is a 6-inch coast-defense gun, and it is claimed that it will carry 30 miles. A projectile fired from it has a velocity of 3,500 feet a second. An improved type that is now being proposed is expected to carry much farther. This weapon, some believe, will cause the American gun to become more famous than the Krupp.

The Brown wire-tube is 26 feet long, and weighs 20,000 pounds. It is built to withstand a pressure of 100,000 pounds at the breech and 50,000 pounds at the muzzle. This muzzle strength is greater than the breech strength of the guns now in use by the American Army and Navy. The manufacturer of the new weapon states:

"The possibilities of guns of this kind are marvelous. It is estimated, for instance, that a 10-inch gun will throw a shell nearly 60 miles, and that a gun of this pattern of larger size will throw a projectile 100 miles. All this is in remarkable contrast with guns made years ago, and especially those used before the Civil War, when they were often made of a single piece of cast iron. While wire-wound guns


By this device an ordinary bicycle can be used on railroad tracks.

are not altogether new, the wire-tube differs from all that have ever before been used in many important respects."

The wire-tube is built of rolled steel sheets, upon which are wound layers of polished steel wire. The lining tube is of forged steel. More than 20 miles of square steel wire is wound over the steel sheets. Then a trunnion jacket of forged steel is shrunk over the wire. At the breech of the gun there are 21 layers of wire and at the muzzle seven layers. The tension in winding is about 128,000 pounds to the square inch. The wiretube is the invention of J. Hamilton Brown. It is believed to have a great

advantage over all other guns because of its enormous powers and its tensile strength and elasticity.

Military Track Bicycle

Germany has attained distinction of late through the manufacture of some very meritorious devices. One contrivance of German origin that is of special interest, is an arrangement known as a "military track bicycle," whereby an ordinary bicycle may be used on track rails, enabling the soldier to carry his piece handily and fire it when he desires without dismounting. It is planned to use this unique contrivance in the Russian army in guarding the Trans-Siberian railroad. In the frame of a light guiding carriage of Mannesmann tubing, one or two bicycles are placed and easily connected, the whole forming a solid car, as it were. The apparatus can be taken apart in a few seconds, and assembled according to need. It can be driven by one or two persons. The inventor is


Lieutenant von Trutzschler of the Kaiser Alexander regiment, who thinks that the contrivance will serve to lighten the difficulty of railway patrol service in all wars of the future.

A New Type of Submarine

From Japan comes the news that Captain Oda, inventor of the types of submarine mines used by the Japanese, one of which destroyed the Russian flagship Petropavlovsk, has invented a new engine-something between a torpedo and a mine-charged with nitro-glycerine in enormous quantities and driven by an oil motor. When Russia's Baltic fleet reaches Eastern waters, if it ever shall, these engines will be used against it; and positions are already prepared in Formosa and the Loo-Choo islands with that object. There will be no crew on board these vessels, which apparently will steered by some application of wireless electricity. Full precautions will be taken to prevent any accidents to neutrals; and, as explosion takes place after a certain lapse of time, there will be no risk of live mines remaining adrift on the high seas.

Great Technical Schools

Stevens Institute of Technology, Hoboken, N. J.


Associate Professor of Mechanical Drawing and Designing


TEVENS INSTITUTE OF TECHNOLOGY, the first technical school for instruction in the subject of Mechanical Engineering, was established in 1871 through the munificence of Mr. Edwin A. Stevens, who was the surviving member of a family trio that will ever rank among the greatest of the world's pioneer engineers.

A Family of Engineers

A word, in passing, may not be amiss to indicate what these three men (Col. John Stevens and his two sons, Robert L., and Edwin A.) accomplished, and how substantial a foundation they laid for the prestige that is attached to the name of Stevens. Before the close of the eighteenth century Col. John Stevens was engaged in steamboat construction, and, in the year 1804-three years before Fulton's Clermont was started as a commercial enterprise-operated a steam propeller boat on the Hudson River. His early plans, however, were many years in advance of the mechanic's art; and the propeller, now so universally employed, did not come into successful use for a long time after. In 1807 he had under construction the paddle-wheel vessel Phonix in his own shops at Hoboken; but Fulton in that year imported an engine built in England by Watt, and placed it in the Clermont, thus being the first to make practical application of side-wheel boats. By this act Fulton secured exclusive rights to the waters of New York State for steam navigation. Thus prohibited from operating his steamboats in home waters, Colonel Stevens sent the Phonix around to Philadelphia in 1809, under the supervision of his son, Robert L. Stevens. This was the first steam vessel to brave the fury of old ocean. "For the resolute, there is ever the open sea."

While the construction of the Erie Canal was under discussion by the legis

lators of New York State in 1812, Col. John Stevens earnestly petitioned them to construct a railroad instead of the canal, and ventured to predict that an average speed of thirty miles per hour could be attained, and that sixty miles might be. Twenty years later he built, as a private venture, on his own estate in Hoboken, the first locomotive and railroad track in America. This was soon followed by the construction of the Camden & Amboy Railroad, now a part of the Pennsylvania System.

During the war with England in 1813, Robert L. Stevens invented the elongated shell to be fired from cannon. In 1814 Col. John Stevens projected the circular iron fort to be revolved by steam; and under his direction his son Edwin carried on experiments to determine the results of firing cannon against iron plates, as a result of which the Stevens brothers conceived the plan of applying iron plating to war vessels. In 1841 they entered into negotiations with the United States. for the first armor-plated battleship.

Such were some of the inventions and enterprises of the Stevens family of engineers. But this is not all, for in the development of their comprehensive plans in those early days, it was necessary to invent many objects of detail which of themselves are of no small importance. Thus, when Col. John Stevens invented the tubular boiler, and applied the principle of the screw to propeller blades in order to carry on his experiments in navigation, there was no patent protection in this country; and so, on his petition, the Patent Law of April 10, 1790, was founded. In order to carry on the work of railroad development, Robert L. Stevens invented, in 1830, the T-rail and the railroad spike which are now in universal use for track construction on steam roads. It was R. L. Stevens who used steam expansively, in 1815; who

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is not the purpose of this article to enter into any further detail of their engineering work. This digression is made, first, to show that the establishment of the Stevens Institute of Technology as a school of Mechanical Engineering was a fitting outgrowth of the busy and successful lives of three pioneer engineers; and secondly, to record a matter of public interest not generally known.

strong faculty, first opened the doors of Stevens Institute for the reception of students. During the first year, 21 young men were in attendance-2 Juniors, 3 Sophomores, and 16 Freshmen. The first graduate of Stevens Institute was J.


Founding of the Institute

Edwin A. Stevens died in 1868, leaving in his will a block of land adjoining the family estate at Castle Point, Hoboken, N. J.; $150,000 for the erection of a building; and $500,000 as an endowment fund for an "institution of learning."

On the third Monday in September of the year 1871, the Trustees, having erected a suitable building and assembled a

Augustus Henderson, M. E., the sole member of the first class of 1873, and the first person to receive legally the degree of Mechanical Engineer.

Dr. Henry Morton was early engaged as President by the Trustees; and he aided largely in laying down the plans for the new institution, and in selecting the first faculty. This was a most important task, for, while there were technical schools in this country and abroad, they were devoted mostly to Civil Engineering. There was no course anywhere in Mechanical Engineering after which to pattern. Under these circumstances the outline on which the work of the new institution was laid down by the Trustees and President Morton was most remarkable, for nothing that they prescribed has, in these thirty-three years, been found useless in a thorough course of in

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