USE OF TRENCH ARTILLERY.
76.—Use with a purpose.
Whatever trench artillery appliances are provided, bomb-throwers, trench mortars, catapults, etc., they should never be used hap-hazard, but always with great deliberation and forethought.
Have a distinct end in view and watch for the best opportunity to attain it.
Such definite aims may be: to interfere with a relief, a fatigue, a trench construction or repair, to destroy accessory defences, etc.
77.—Keep it ready.
Let the mortars, etc., be kept loaded and trained on the target selected, ready to be fired instantly. The crews should be near at hand and a sentinel posted to watch for a favorable opportunity.
78.—Save ammunition.
Until this opportunity occurs, do not fire.