will not occupy their fire positions unless an attack is imminent, but should be posted with the reserves in their own section of the defence. This must not prevent emplacements or pits for the guns being made, ranges carefully taken and written up, and everything being ready in case of action. These positions and the subsequent action will correspond so closely with those already suggested for infantry in the defence in the last chapter, that they need not be repeated. By night, however, the case is very different, and it is necessary to select very carefully the position of each gun, so that it commands a road, a bridge, or other ground which the enemy in advancing may be compelled to pass or occupy. These places must be selected in order of importance, and an endeavour made to leave no approach by which a body of troops might move uncovered by fire. The machine guns must occupy their positions before dark and be carefully laid to sweep the area of ground necessary for protecting the position, the angle of elevation of the gun being taken by clinometer afterwards in order that it may be relaid if necessary in the dark. Great care must be taken to conceal these guns from observation when bringing them into position or withdrawing them, and it is worth while going to some considerable trouble to do this. One method of many is suggested to show what is meant. Field guns might be placed in the positions by day and withdrawn before night,
