GATLING GUN, a machine-gun of the mitrailleuse order, invented by Dr. R.. J. Gatling of Indiana, in 1861. It has generally 5 or 10 barrels, each barrel has a corre sponding lock. Although the barrels and locks revolve together, the locks have a for ward and backward action, By means- of the forward motion the cartridges are placed in the chambers of the barrels and the breech is closed when the discharge occurs; while through the agency of the backward motion the empty cartridge cases are extracted. The Gatliug gun is fed by feed-cases which are made to fit in a hopper communicating with the chambers. Continuous firing can be carried on at the rate of 1000 shots a minute, as one case is replaced by another as fast as it is emptied. The tive-barrel gun weighs 100 lbs., is mounted ou a tripod, and can be fired at the rate of 800 shots a minute. The bore of each barrel extends through from end to end, and the breech is chambered to receive a flanged "center-fire" metallic-case cartridge of the kind that are in use for the Springfield rifle and similar arms. The breech ends of all the barrels are screwed into a disk called the rear barrel-plate, which is fastened to the central shaft; the muzzles pass through another disk called the front barrel-plate, on the same shaft.
A hollow Metal cylinder is fastened.ipon 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 acting on a 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 is worked by an endless screw on a small axle placed at right angles to the shaft and furnished outside with a baud crank. When the lock-cylinder revolves it carries the locks around with it, and gives them a longitudinal reciprocal motion by their rear ends sliding along a groove in the inclined surface of the stationary spiral cam, so that i the several locks in succession are forwarded towards their respective barrels. The Gaffing gun is elevated and lowered like an ordinary field gun, but it has the disadvan tage as compared with shell guns of not being able to deliver a curved fire. It is con structed with calibers of 1-in., weight 650 lbs.; .75-in. and .65-in., each weighing 450 lbs.; .55-in., weight 400 lbs.; and .50-in., .45-in., and .42-in., each weighing 200 lbs.