Page:The New International Encyclopædia 1st ed. v. 12.djvu/700

MACHINE GUN. 620 MACHINE GUN. ■with .1 wheel tuniiiig freely on its own axis. In action, the cartridges were fed into the opening of the breech eases above the carrier block, where they became engaged in the grooves of the swinging piece, and passed directly into the fixed mouth, so that as each cartridge made contact with the wlicel the latter was made to revolve by its imi)act and pressure and thus present the next groove for the next cartridge. As the wheel turned round it car- ried and deposited the carriages in the grooves of the carrier block ready for discharge. The de- vice answered its purpose with regard to the avoidance of jamming, but was as variable and imcortain so far as regards the different angles of elevation as was the old tin case. The 'Accles' feed drum was designed to obviate this dilliculty. and as it fed the gun without the aid of gravity, being in effect a positive feeder, it was independent of the angle of elevation. defect, a feed has been introduced which leaves but a small surface exposed to tire and is in other respects entirely free from the defects oi its predecessors. Long strijis of some cheap flexi- ble metal, tin preferably, liaving tongues or slits (one end of each of the former attaclied to the stri|)s, while the other is se])aratcd, and so sur- round the cartridge as to keep it in position on the strip) , are fed into the opening of the hopper. The rotation of the crank compels the projections on the grooves of the carrier block acting upon the cartridges to force the strip through the hopper. Thus each cartridge is in turn de- posited in the groove of the carrier block, tin- empty strips being discharged to the right. The Gatling gun with improved feed has attained a rate of fire about 20 rounds a second. The Gardner gun closely resembles the Gatling .so far as regards the principle of rapid fire. It consists of two barrels parallel to each other and COLT ACTOMATIC OCX. The invention consisted of a two-headed drum, connected by a sheet-brass casing, the heads also being of brass, and the distance between the two equal in length to that of a cartridge. Each head was grooved in a spiral form. The car- tridges are inserted in the drum through the nioutli and rest in the spirals and between the radial arms.. To fire the gun. the feed drum is inserted in position directly over the carrier- block, the opening of the drum resting over the grooves of the block with the planes of its heads in position with the axis of the barrels. The movement or rotation of the crank causes the lock cylinder, barrels, etc., to revolve: and at the same time the groove projections of the car- rier block force the radial arms of the drum to rotate. The gieat objection to this device was that while the feed was perfectly regulated, caus- ing no deviations of elevation, yet the weight of the drmn was a serious <lrawback. besides which, a bullet striking its exposed surface instantly put it out of action. To avoid this very serious having their axis in the same horizontal plane. Its component parts otiier than the liarrcls are: the casing, bolts, tiring, and extracting mechan- ism, cams, and feed valve and guide. The ea-- ing is of bronze and forms a support as well :i- protection for the barrels. A current of air i~ caused to circulate around the barrels by means of two openings made in the top and bottom. The rear part of the easing (box-shaped) con- tains the mechanism. The two U-shaped bolts (one for each barrel) have a backward and for- ward movement in the casing. The firing and extracting mechanism is both simple and in- genious, the feed valve and guide closely re- sembling the Bruce guide already explained in connection with the Gatling gun. except that it is without a wheel and is attached to the casing in the rear of the barrels. It is so arranged as to cause the cartridges to drop from the feed guide through the holes in the easing and from thence into the chamber, into which it is forced by the bolt. This action opens the other barrel, which