Courtesy of "Scientific American"
The Lewis Gun which produces its own cooling current
Courtesy of "Scientific American"
The Benèt-Mercié Gun operated by gas
Explosion is the same thing as burning. The only way that the explosion of gunpowder differs from the burning of a stick of wood is that the latter is very slow, while the former goes like a flash. In both cases the fuel turns into great volumes of gas. In the case of the gun the gas is formed almost instantly and in such quantity that it has to drive the bullet out of the barrel to make room for itself. In the cartridge that our army uses, only about a tenth of an ounce of smokeless powder is used, but this builds up so heavy a pressure of gas that the bullet is sent speeding out of the gun at a rate of half a mile a second. It travels so fast that it will plow through four feet of solid wood before coming to a stop.
(C) Committee on Public Information
Browning Machine Rifle, weight only 15 pounds
