Bomb

Bomb, BOMB-SHELL, or SHELL, is a hollow projectile, usually of cast iron, fired from a mortar or other large piece of ordnance, filled with gunpowder, and fitted with a time-fuse, which causes it to burst at any required instant after it is fired. The fragments are most destructive both to men and material, and the flame of the explosion sets fire to anything inflammable with which it comes into contact—even earthen parapets are much damaged by bombs, which, lodging in them and then bursting, have the same effects as a mine sprung under them. Such projectiles were formerly fired from mortars only; but all modern pieces of artillery now fire them. The name shell has, however, been generally substituted for that of bomb, especially since the introduction of rifled guns firing elongated projectiles. The largest spherical bomb ever made is 26 inches in diameter and weighs 21 ewt., for Mallet's gigantic mortar, now in Woolwich Arsenal, but only a few were ever fired, as the mortar was found to be too weak to bear the shock of discharge. The 13-inch is the largest spherical shell in ordinary use. It weighs about 195 lb., with a thickness of metal varying from $\backslash frac\{1\}\{2\}$ to 2 inches at different parts; it bursts with about 8 lb. of powder. The 10-inch bomb, weighing about 90 lb., is proportionately less in all dimensions than that just described. The smallest is the one-pounder shell of the 'pom-pom' machine gun. The elongated projectiles used with modern heavy guns, some weighing as much as three-quarters of a ton, are all hollow. See SHELL, MORTAR, INFERNAL MACHINES, MACHINE GUN.