Plate 25a.—Trench mortar.
Plate 25b.—Improvised catapult.
Cover for Supports
At a variable distance to the rear of the first line fire trench is located the cover for supports, which is organized much in the same manner as the first line system of trenches and affords a second position in the system to fall back to in case of necessity. These trenches are provided with overhead cover and numerous dugouts for the protection of the men.
Machine Guns