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hole punching machine, which is accounted the heaviest in the United States, and which, with a pressure of 1,500 pounds, punches a manhole 18 by 27 inches in size from plates 34 inch thick; 32-foot bending rolls, which are the largest in the world ; some of the heaviest cutting shears ever made, with maximum dimension of cut of four inches; 36-, 60-, and 84-inch planers; a wall planer measuring 22 feet plane by 22 feet slot, which has no parallel in the world; and a 125-inch shafting lathe, which will take

of power riveting which surpasses anything previously attained anywhere in the world. At first an attempt was made to use pneumatic compression riveters similar to those in use in many bridge shops; but it was soon demonstrated that their great weight for the large gaps necessary in shipbuilding made it impracticable to handle them with either facility or economy in the case of ships on the stocks.

The shipbuilders, however, knew from experience, of the value for chipping and calking of the pneumatic hammer, consisting of a piston rapidly reciprocating inside of a cylinder, and striking the end of a chisel; and this apparatus was gradually adapted to the driving of rivets.

plating so heavy that to draw it up requires rivets too large to be properly driven by hand. From an economical standpoint, the power riveters perform wonders. In deck and tank topwork, for instance, three men and a heater boy will drive from 800 to 1,000 rivets a day. Not only is the whole operation of driving a rivet completed much more quickly than by hand, but it is done so expeditiously that the rivet has not lost its heat ere completion, and consequently there is gained the benefit of the resulting contraction, which, as the rivet cools, draws everything together with firmness.

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PNEUMATIC HAMMER IN OPERATION. Now it is possible to drive every rivet in a ship with machines which are very light, short enough to go between the frames of the vessel, and of sufficiently small diameter to render them thoroughly portable. Even shell rivets are closed up with the greatest ease and facility.

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PNEUMATIC Steel Cutter IN OPERATION.

Shipbuilders in this country who have made a careful computation, figure out that machine riveting, adding the cost of

air, repairs, etc., effects a saving of from IRON CORNER CUTTER.

one to two cents per rivet over pieceThe adoption of these power riveters work prices for hand riveting, the decame just at the most opportune time, gree of economy depending upon the lofor the increase in the size of ships of cation in the ship, and averaging fully late years has involved the necessity for 194 cents. In the shipyards on the Great

the limit for reaming and tapping being 1/2 inches. Such a drill requires about 25 feet of free air per minute to operate it at 80 pounds' pressure. Side-light cutters, deck-boring machines, and other pneumatic appliances also have place in the equipment of the modern shipyard. Some yards have in use at one time as many as 400 portable riveters, calkers, drills, etc. Power for the machines is

Lakes, where pneumatic machinery of this class is used very extensively, the saving on an ordinary lake steamer of 4,000 tons is from $4,000 to $5,000. One machine will not infrequently drive 450 78-inch rivets in a single day. At the regular hand-work rate, this would involve an outlay of $15.75; whereas, with the machine, the cost is but $5.50, including the wages of operatives and the cost of power.

Another class of pneumatic tools in use in shipyards consists of chipping, calking, and bending hammers, machines which range in weight from 7 to II pounds and which have a stroke of from one to four inches at speeds varying from 3,400 to 2,200 strokes per minute according to size. These hammers require 20 feet of free air per minute, and work at a pressure of from 70 to 80 pounds. The heavy chipping hammers weigh fifteen pounds, and attain a speed of 1,200 blows per minute for the 7-inch stroke. Most powerful of all the hammers is what is known as the “9-inch stroke riveting hammer," which has a speed of 905 strokes per minute. A pneumatic holderon is in use in many shipyards, instead of the ordinary bar, for holding up the head of the rivet. It can readily be put

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furnished in most instances by a 21/2inch main; and an air pressure of at least 110 pounds is carried, supplied by an air compressor capable of delivering, say, 5,000 cubic feet of air per minute.

Machine and Brass Shops The machine and brass shops and other under-cover portions of modern American shipyards have within the past few years shown vast improvement in equipment and arrangement. An ideal structure of this kind—the newest shop at the Cramp plant—is 335 by 143 feet, and of steel-skeleton framework construction. The floor load in the second story is 400 pounds per square foot, while the third floor is designed for a load of 350 pounds per square foot. The structure has a main central traveling-crane runway, served by two 50-ton electric cranes, with a span of about 57 feet, center to center of supporting girders. On either side of the main central portion are galleries 42 feet wide. The floor space in the lower story of both wings is served by electric cranes of from 10 to 30 tons capacity.

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Some idea of the magnitude of a present-day shipyard of the first class, may be gained from the fact that the Cramp yard at Philadelphia represents an expenditure of more than $7,000,000; and the great shipyard at Newport News, Va., on Hampton Roads, involved an even greater outlay. In the laying out of all our big shipbuilding plants, heavy expenditure has been made to secure convenience, speed, and economy in the conduct of operations—a continuous, unretarded movement forward of the material from the time it enters the yard in raw state until it is ready to leave as part of a completed ship. To this end, buildings have been grouped—at the Cramp plant, joiner, pattern, machine, and erecting shops are combined within the shelter of one immense structure 1,164 feet in length—and all material is conveyed by short hauls.

Use of Electric Power In conclusion, a word should be said regarding the extent to which electrical energy is displacing steam power in the operations of the more important shipyards. Not only are almost all the cranes, large and small, electrically operated, but almost every one of the big machine tools is impelled by an individual motor, thus insuring a great saving, since the power need be turned on only when actually needed. The electrical outfit which at the Newport News yard furnishes power for running all the machines in the shops and also supplies current for the 2,500 incandescent and 150 arc lights in the plant, consists of three 600-K. W. generators driven by three compound engines; two 125-K. W. generators driven by one horizontal-compound engine; and two 75-K. W. generators driven by simple engines.

The Machinery of Modern Warfare

No. II. Ingenious Devices that Increase the Efficiency of Peacemakers

By RUTLEDGE RUTHERFORD

THIS IS AN AGE of new ma- durance of the English, but incited the

chines of war. In the last issue Englishman's wits, awakened his latent of THE TECHNICAL WORLD were mechanical genius, and brought forth

described several of the new new inventions that have surprised the weapons and methods of destruction that world. In Thibet the British are now were making their appearance in the Jap- testing for the first time several marvelanese-Russian war. But these are not ous new contrivances that had their inall. The fever to invent devices that will ception in ideas originating in South destroy life and property in the quickest Africa. and most wholesale manner, is catching;

The Hyposcope and nations seem to vie with one another The very newest of these contrivances, in their efforts to produce the most deadly and one that has a most promising future, Weapons. Indications are that the next is a new rifle-sight that enables a soldier decade will witness radical changes in the to shoot at the enemy while the marksfeatures and methods of manufacture of man hides behind a rock or tree or otherall war materials.

wise completely obscures himself. This The new era of fighting devices is regarded as war's masterpiece of prothrough which we are now passing, tective mechanism, and is causing a great seems to have had its birth in the recent amount of comment in Europe. The South African war. That stubborn strug- sight is called the “Hyposcope.” The gle not only tested the courage and en pictures of the rifle with the new arrange

ment, herewith presented, are the first means of a screw placed several inches that have been printed in any American below the rifle back sight so that the periodical.

need ful elevation can be obtained without

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SOLDIER SIGHTING RIFLE BEHIND PARAPET, BY MEANS OF HYPOSCOPE.

moving the rifle from the rest or exposing any part of the marksman to the enemy.

An ingenious arrangement of mirrors is the basis of this new and remarkable invention. The mirrors are contained in a light, strong metallic case, which is easily attached to the rifle and which enables the marksman to take aim from behind an embankment or other obstacle, without exposing himself. When first tested a short time ago in Thibet, the hyposcope fully demonstrated all that was ever claimed for it. The Thibetans, falling before the fire of the unseen foe, were completely nonplussed and fled in dismay, declaring that the very rocks and hills rained death on them when they went forth to fight the British. The result has been to create an uncontrollable superstition among the Llama's forces that they are the objects of Divine enmity and that the unseen powers of Providence are fighting against them.

The hyposcope, it is claimed, can be used at any range shown on the back sight of any rifle. Shooting may be as accurately continued without an ordinary back sight as with one—which is equivalent to an additional back sight, should that on the rifle be rendered useless. A trustworthy telescope is thus also added. The elevation of the hyposcope can be accurately and immediately effected by

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