in military affairs, a large shell of cast iron, having a great vent to receive the fusee, which is made of wood. The shell being filled with gunpowder, the fusee is driven into the vent or aperture, within an inch of the head, and fastened with a cement made of quicklime, ashes, brick-dust, and steel-filings, worked together in a glutinous water; or of four parts of pitch, two of colophony, one of turpentine, and one of wax. This tube is filled with a combustible matter, made of two ounces of nitre, one of sulphur, and three of gunpowder-dust, well rammed. To preserve the fusee, they pitch it over, but uncase it when they put the bomb into the mortar, and cover it with gunpowder-dust; which having taken fire by the flash of the powder in the chamber of the mortar, burns all the time the bomb is in the air; and the composition in the fusee being spent, it fires the powder in the bomb, which bursts with great force, blowing up whatever is about it. The great height a bomb goes in the air, and the force with which it falls, makes it go deep into the earth.

Bombs may be used without mortar-pieces, as was done by the Venetians at Candia, when the Turks had possessed themselves of the ditch, rolling down bombs upon them along a plank set sloping towards their works, with ledges on the sides, to keep the bomb right forward. They are sometimes also buried under ground to blow up. See CAISSON.—Bombs came not into common use before the year 1634, and then only in the Dutch and Spanish armies. One Malthus an English engineer is said to have first carried them into France, where they were put in use at the siege of Collioure. The French have lately invented a new sort of bombs of vast weight called comminges.—The art of throwing bombs makes a branch of gunnery, founded on the theory of projectiles, and the laws and qualities of gunpowder. See GUNNERY, PROJECTILES, GUNPOWDER, &c.

Bomb-Chief, is a kind of chest filled usually with bombs, sometimes only with gunpowder, placed underground, to tear and blow it up in the air with those who stand on it. Bomb-chiefs were formerly much used to drive enemies from a post they had seized or were were about to take possession of: they were set on fire by means of a flancliers fattened at one end, but they are now much disinfected.

**Bomb-Vecells**, which are small ships formed for throwing bombs into a fortress, are said to be the invention of M. Reyneau, and to have been first used at the bombardment of Algiers. Till then it had been judged impracticable to bombard a place from the sea. See Ketch.