The machine gun possesses the power of delivering a volume of concentrated rifle fire which can be rapidly directed against any desired object. Rapid fire cannot be long sustained, owing to the expenditure of ammunition involved, and it is therefore necessary that the movements and fire action of the weapons should be regulated so as to enable them to open fire immediately a favourable opportunity arises. Surprise is an important factor in the employment of machine guns, which should be concealed, and whenever possible provided with cover from fire. The massing of machine guns is likely to attract hostile artillery fire. For this reason it is usually better to employ them in pairs in support of the particular body of troops to which they belong. When an overwhelming fire on a particular point is required it can be provided by concentrating the fire of dispersed pairs of guns. The guns of two or more units may, if required, be placed under the command of a specially selected officer and employed as a special reserve of fire in the hands of a brigade commander. Machine guns are best adapted for use at effective infantry ranges, but when good cover from view and fire exists they may be usefully employed at close infantry ranges.[62] _With Outposts_ Machine guns with outposts may be employed to sweep approaches, and to cover ground which an enemy in advancing may be compelled to pass or occupy.[63] _During the Battle_ Machine guns will be especially valuable in bringing a sudden fire to bear from such positions, both in order to cover a further advance and to assist in defeating counter-attacks. Machine guns can normally support an attack most efficiently from well-concealed positions provided with good cover, and within effective infantry range of the enemy. Occasionally, when good opportunities for a concealed advance present themselves, they may be established within close infantry range of the objective.[64] _From_ “CAVALRY TRAINING,” 1907 Machine guns afford a means of developing fire without dismounting men from the squadrons. During the cavalry fight they will usually be massed under one commander, but may be employed in pairs when necessary. They will co-operate with the horse artillery, the great volume of fire which they are able to bring to bear from a narrow front being particularly effective. Their presence with the artillery will often admit of the latter dispensing with any other escort.[65] _Position of Machine Guns_ During the approach march the machine guns will usually accompany the artillery, to whom they may act as escort when necessary.[66] _From_ “INFANTRY TRAINING, 1908” (AMENDMENT, AUGUST, 1909) _General Characteristics_ 1. The machine gun possesses the power of delivering rapidly from a narrow front a volume of closely concentrated fire which can be controlled easily, be turned readily in any desired direction, or be distributed by traversing.