RAVELIN

, in Fortification, was anciently a flat bastion, placed in the middle of a curtain. But

Ravelin is now a detached work, composed only of two faces, which form a salient angle usually without flanks. Being a triangular work resembling the point of a Bastion with the flanks cut off. It raised before the curtain, on the counterscarf of the place; and serving to cover it and the adjacent flanks from the direct fire of an enemy. It is also used to cover a bridge or a gate, and is always placed without the moat.

There are also double Ravelins, which serve to defend each other; being so called when they are joined by a curtain.

What the engineers call a Ravelin, the men usually call a demilune, or halfmoon.