Plate 3.—Abatis.
Abatis (pronounced abatee) consists of branches of trees lying parallel to each other, butts pointing to the rear, and the branches interlaced with barbed wire. All leaves and small twigs should be removed and the stiff ends of branches pointed. The butts are staked or tied down of, anchored by covering them with earth. When more than one row is used the branches overlap the butts of those in front so as to make the abatis about 5 feet high. An abatis formed by felling trees towards the enemy, leaving the butt hanging to the stump, is called slashing.
Plate 4.—Slashing.
Wire Entanglements
Barbed wire is the material most employed in the construction of obstacles. It may be used in the following manner:
1. As a simple trip, for giving the alarm. It is stretched just above the ground and attached to some object that will cause a noise to be made if molested.