By concealment is meant screening from view but not necessarily protection from fire.
[1421]. Rising and falling ground. The influence of the ground upon the effect of fire is at once seen by studying [Fig. 44].
If the ground rises, as shown by B O and A O, the depth of the beaten zone (and consequently the effect of fire) decreases. On the other hand, if the ground falls (up to a certain point), the depth of the beaten zone (and consequently the effect of fire) increases.
[1422]. Depth of beaten zone affects only targets having depth. It should be remembered that depth of beaten zone can affect only targets which have depth.
On a target in the form of a line,—a line of skirmishers, for example,—the depth of the beaten zone has no effect one way or the other. If such a target, however, is backed up by supports and reserves, the depth of the beaten zone may have a decided effect on them, depending upon their distance in rear of the line forming the target and the slope of the ground in rear of such target.
In this connection, attention is invited to [Fig. 47], which shows how in the case of a fire delivered from a height at a target on a horizontal plane beneath, the beaten zone is shortened and consequently the fire effect decreased.
Fig. 47
An example of increasing the depth of beaten zone is seen in [Fig. 48], which shows a fire delivered from low ground at a target on the edge of a plateau or crest of a ridge from which the ground slopes to the rear.