Station all the other men in the shelters of the support trench, or along the communication trench, if there are no shelters, but fully equipped and ready to jump to their places in the fire trench as soon as the enemy's artillery fire will stop or lengthen to allow his infantry to advance.
72.—Fire to impede observation.
All through the bombardment, the sentinels should fire at all objects in the distance which may be used as observation posts. The machine guns should cooperate with a slow sweeping fire.
73.—Case II.—Bombardment back of Fire Trench.
74.—Watch for infantry attack.
All should stand to in the fire trench watching for a possible infantry attack and for a possible shortening of the enemy's bombardment. If it occurs, proceed as in Case I.
75.—Prevent observation.
Fire against possible observation posts as in Case I.