Light-ball.
（Ordnance.) The ordinary lightball, which has been in military use for centuries, consists of a canvas sack of elongated shape, filled with a combustible and illuminating composition. It is used for lighting up works in sieges, and also for discovering the position of an enemy; in the latter case it is charged with a shell to prevent its being approached, and is fired from a piece of ordnance. As from its position on the ground it can illuminate but a limited area, parachute lightballs have been proposed. That of Sir William Congreve was to be attached to a rocket. General Boxer's light-ball was adopted into the British service in 1850. It consists of a mass of sulphur, saltpeter, and red orpiment, inclosed in a hemispherical case of tinned iron, which is attached by chains and cords to a large calico parachute that is compressed into a similar hemispherical casing, the two forming a sphere, having an annular depression surrounding it. A second tinned-iron case fits over the first, and has a fuse communicating with a train of quickmatch in the annular groove before mentioned, and also with the bursting charge. This projectile is fired from a mortar.
