ORGUES, in the military art, are thick long pieces of wood, pointed at one end, and shod with iron, clear one of another; hanging each by a particular rope or cord, over the gateway of a strong place, perpendicularly, to be let fall in case of the approach of an enemy.
Orgues are preferable to heracs, or portcullices, because these may be either broke by a petard, or they may be stopped in their falling down: but a petard is useless against an orgue; for if it break one or two of the pieces, they immediately fall down again and fill up the vacancy; or if they stop one or two of the pieces from falling, it is no hindrance to the rest; for being all separate, they have no dependence upon one another.