gas carbon (gas karbon)

Solid carbon formed in gas-retorts. See carbon. Also called in England gas - cinders and gas - coke. gas-check (gas'chek), n. A device for preventing the escape of gas through the vent or around the breech-mechanism which closes the rear end of the bore or chamber of any breech-load ing small-arm, machine-gun, or cannon. In small arms the metallic cartridge-case, copper or bra , serves as an effective gas-check. (See obturation, obturator, fermeture.) The Broad well gas-check consists of a curved steel or copper ring and a circular bearing-plate slightly IMG:content-2121.png:[blocks in formation] AA , breech-block; BB , expanding bolt and bolt-head; CC , expanding steel ring or gas-check; S , spiral spring; D , check-nut and set-screw. hollowed out. The curved ring is fitted into a counterbore or rece in the rear end of the bore or chamber, and is held firmly in position by the breech-closing apparatus carrying the bearing-plate. The ring is self-adjusting in its seat, and the bearing-plate is easily adjusted. On firing, the gas expands the lip of the ring against the IMG:content-2122.png:[blocks in formation] A , rear elevation of ring; B , section of bore, ring, and bearing plate; a a , section and elevation of ring; b , bore of gun; c , section of bearing-plate; dd , walls of gun. walls of the chamber, and this expansion prevents the escape of gas. The Krupp guns are furnished with this device.