OKDNANCE. 



107 



other through a pipe or through holes in the piston or 

 sides of the cylinder, and the_ recoil gradually taken up. 

 With large guns the piston is made in two discs, one 

 turned by means of small projections that fit into spiral 

 grooves in the cylinder. At the beginning of the recoil 

 the holes in each disc coincide, but as one disc turns it 

 gradually shuts off the holes in the other, and as the 

 orifices are made smaller the resistance to the passage 

 of water through them increases as the gun recoils. 



The gun is run put again after recoil by power or by 

 having the slide inclined, and the gun returns to its 

 position before recoil by gravit3'. The gravity-return 

 principle, it appears, was first used by Wahrendorff for 

 his rifled gun. 



The pneumatic carriage is an American invention by 

 Mr. A. J. Powlett, of New York. A carriage was 

 built for a 54-ton carriage, and tried by the army at 

 Sandy Hook. It is a gravity-return carriage, in which 

 the recoil was taken up by the compression of air in a 

 cylinder which was attached to the slide, the piston 

 being attached to the carriage. The training and ele- 

 vating was done by compressed air working in pneu- 

 matic engines. The entire mechanism in this carriage 

 is crude, and, while the results were not such as were 

 promised, they were better than could have been ex- 

 pected with the carriage as it was, and were amply 

 sufficient to warrant further trials, and the navy has 

 contracted for an 8-in. gun-carriage, in which the 

 recoil is to be taken up and the gun elevated, trained, 

 and loaded by compressed air. A contract has also 

 been made for four 10-in. gun-carriages for the 

 monitor Terror. The entire arrangement is now differ- 

 ent from the first carriage, and preliminary trials lately 

 made at Sandy Hook with a small experimental car- 



riage were such as to lead to the belief that the govern- 

 ment will have developed by this contract on its com- 

 pletion an efficient carriage for use with guns of large 

 calibre. 



Machine- Guns. In the invention of machine-guns 

 and small-arms America has led the world, though in 

 nearly all cases the inventor has had to go abroad to 

 have his invention appreciated. 



The Gatling-gun, invented by Dr. R. J. Gatling, an 

 American, fires bullets with great rapidity. The gun 

 most in use has 10 breech-loading barrels, each with 

 its own lock, the barrels and locks revolving together 

 about a common axis. The barrels are revolved by 

 means of a crank, and as they revolve the several 

 operations of loading, firing, and extracting the car- 

 tridge are carried on continuously. A feed-case, con- 

 taining about 40 cartridges, is placed over the lock- 

 chamber, and the cartridges fan into the proper re- 

 ceivers, and when it is empty another replaces it. The 

 ordinary rate of firing is about 800 a minute. Fired 

 with careful aiming at a target 19 ft. long and 11 ft. 

 high, distant 1000 yards, 665 hits were made out of 

 1000 shots. 



The Driggs-Schroeder rapid-fire gun is one of the 

 most promising rapid-fire guns now offered. Great 

 initial velocity, with corresponding great accuracy and 

 penetration, is obtained with a lighter gun than with 

 other guns of like type and calibre. Shots can be fired 

 with the 3-pounder at the rate of 30 per minute. 



The Hotchkiss revolving-cannon is also an American 

 invention ; resembling the Gatling somewhat on the 

 exterior aspect, but differing entirely in interior 

 mechanism, and firing a shell instead of a bullet. It 

 consists of five barrels grouped around a common axis, 



Driggs-Schroeder Eapid-Fire Gun. 



The breech mechanism is shown in the accompanying cut. Fig. 1 showing the breech closed, Fig. 2 the breech open, 

 and Fig. 3 a section through the line zz in Fig. 1. To open the breech, turn the bolt B to the rear, which turns the cam 

 A, till the point d passes from beneath the horizontal wall ab, when the toe of the cam A presses against the lower por- 

 tion E of the hreech-block, and forces the block downwards, d moving along the line be. While this is being done the 

 bottom of the grooved recess in the cam takes against the cocking-lug A on the firing-pin C, and forces it back agan 

 a spring until the full cock-stud is caught by /, which happens just as the shoulder g on the block passes into the recess 

 / on the cam. The rilw XX are now released from the grooves in the breech, and the bolt is in the upper part ot 

 the slot D. The block ran now be turned down to the position of Fig. 2, being guided by the grooves m, into which 

 project guide-studs 7 fixed in the breech. There are two extractors, one on each side, for withdrawing the empty car- 

 tridge-case. The gun is fired by means of a trigger, which draws I down to disengage i, which allows the tring-pm to 

 ipring forwwd. 



