Fig. 48
[1423]. Grazing fire. Shots which pass over a crest with an angle of fall conforming, or nearly conforming, to the slope of the ground beyond the edge of the crest (as shown in [Fig. 48]), are called grazing shots and fire so delivered is called grazing fire.
[1424]. Diminution or increase in fire effect due to rising and falling ground. In connection with the diminution or increase in fire effect due to rising and falling ground, attention is invited to the following:
1. If the ground slopes upward to the rear from a firing line, the supports may be placed closer without increasing the danger from fire aimed at the firing line.
2. When the ground slopes down and to the rear from the firing line forming the target, the supports must be posted at a greater distance in rear, unless the slope is so much greater than the angle of fall of the hostile bullets that a defiladed space is created in which no bullets strike, in which case the supports may be brought up close to the crest.
3. On ground rising with respect to the line of sight, column targets (i. e., having depth) will suffer greater losses than lineal targets.
4. On ground falling with respect to the line of sight, the reverse slope of hills or the level grounds of plateaus, line targets will suffer the greater losses.
[1425]. Ricochet shots. When a bullet strikes any surface and is deflected it is called a ricochet shot.