TRENCHES

, in Fortification, are ditches which the besiegers cut to approach more securely to the place attacked; whence they are called lines of approach. Their breadth is 8 or 10 feet, and depth 6 or 7.

They say, mount the Trenches, that is, go upon duty in them. To relieve the Trenches, is to relieve such as have been upon duty there. The enemy is said to have cleared the Trenches, when he has driven away or killed the soldiers who guarded them.

Tail of the Trench, is the place where it was begun. And the Head is the place where it ends.

Opening of the Trenches, is when the besiegers first begin to work upon them, or to make them; which is usually done in the night.