or Cercus, in the art of war, an iron cage, or hollow capacity, about the bigness of a bomb, of an oval figure, made of ribs of iron, filled with combustible matters, as meal-powder, saltpetre, sulphur, broken glass, shavings of horn, turpentine, tallow, &c. It has two or three apertures out of which the fire is to blaze; and the design of it is to be thrown out. out of a mortar, to set houses on fire, and do other execution. It has the name carcase, because the circles which pass from one ring or plate to the other seem to represent the ribs of a human carcase.