=4. Dispersion of Collective Fire.=--When a body of soldiers fires with the same elevation at the same object, the dispersion of shots is accentuated by the varying skill and eyesight of the men, with the result that the cone formed will be of larger dimensions than in the case of individual fire. The dimensions of the cone of fire will again be further increased if the firers are from any cause, such as fatigue or excitement, unsteady; if the rifles are in bad condition or the target indistinctly seen--factors which are all incidental to firing under the conditions of active service. =5. The Beaten Zone.=--(i) The area of ground beaten by a cone of fire is termed the “beaten zone.” It is regarded as a plane surface. Fig. 6 illustrates this zone together with the additional space which would have to be taken into account in reckoning the dangerous space of the cone of fire in consequence of the height of the objective. (ii) =Depth of Beaten Zone.=--The depth of the beaten zone at short ranges need not be considered on account of the flatness of the trajectory, which insures that practically its whole extent from the firers to the target is swept by bullets. The depth of the beaten zone at various ranges with the Mark VI and Mark VII ammunition is as follows: +-------------+-----------------------+ | Distance. | Depth of Beaten Zone. | | +-----------+-----------+ | | Mark VI. | Mark VII. | +-------------+-----------+-----------+ | 500 yards | 220 yards | 300 yards | | 1,000 ” | 120 ” | 180 ” | | 1,500 ” | 100 ” | 120 ” | +-------------+-----------+-----------+ (iii) It will be seen that up to 1,500 yards--when the ground is parallel to the line of sight--the depth of the beaten zone decreases with the range, on account of the increased angle of descent of the bullets. This shrinkage of the beaten zone does not of itself increase fire effect by the closer grouping of bullets, owing to the increased steepness of the angle of descent, which decreases dangerous space. (iv) Beyond 1,500 yards it will be found that the depth of the beaten zone tends to increase in consequence of the influence of atmospheric conditions on the flight of the bullet, the increased effects of errors in aiming, and faults in the rifle and ammunition--all of which combine to increase the dispersion of fire. This increased dispersion does not of itself increase fire effect owing again to the greatly increased steepness of the angle of descent at longer ranges, which results in a correspondingly great decrease in dangerous space.