It will rarely be advisable for machine guns to follow infantry into the firing line, where they present a conspicuous target which attracts fire and renders their withdrawal difficult. We made this mistake in the South African War more than once. At Rietfontein the machine-gun detachment of the Gloucester Regiment, which had followed the battalion into the firing line, was almost annihilated. At Modder River the Scots Guards Maxim gun accompanied the firing line, and the detachment was annihilated by pom-pom fire, and the gun was left on the field alone all day.[20] In the attack on Cronje’s laager at Paardeberg, machine guns were used in the firing line on the left bank of the river, and when the attack failed the machine guns, having suffered severe losses, could not be withdrawn and had to be abandoned till nightfall. When the covering fire of machine guns is no longer considered necessary, they should be withdrawn and concentrated in batteries in rear of the reserve or in such other convenient position as the G.O.C. may direct. They should take this opportunity of refilling belts, replenishing ammunition, water, etc., and if the guns have fired many thousand rounds, of exchanging barrels.[21] They are now at the immediate disposal of the G.O.C. and will be used by him as a mobile reserve. Circumstances vary so in war that it is impossible to particularize in their use at this stage, but their great mobility will render them extremely valuable in the following cases: 1. To assist a turning movement. 2. To reinforce a distant flank. 3. To repel a counter-attack. 4. To hold a captured position. When the infantry reach close range, the point for the assault will have been selected and the reserves massed behind this point. When the reserves have been thrown in, and the fire fight has reached its height, the moment will have arrived when one side or the other will obtain superiority of fire. “_The climax of the infantry attack is the assault which is made possible by superiority of fire._”[22] To assist in the attainment of this superiority of fire is the true rôle of machine guns with infantry, and, as their beaten zone at short ranges is so small, they can safely fire over the heads of prone infantry, even when the latter are within a hundred yards of the target. The guns should now be pushed up to the closest ranges, and fire of the most rapid description concentrated on the point of assault. When it is remembered that the machine guns of a single Infantry Division, as at present organised, can bring a fire of more than ten thousand shots a minute from close range where its accuracy is assured, at this crisis, there will be no need to say any more on the tactical importance of the probable result.