The volume and concentration of its fire necessitate a large and vulnerable target, or ammunition will be expended without adequate results. The first essential is therefore to obtain this description of target and to avoid firing on others which may present themselves. A large and deep target might justify fire being opened at long range, but such targets rarely present themselves on the modern battlefield, and its vulnerability will partly depend on the closeness of the range and partly on its formation. To obtain a suitable target of this description _surprise_ is essential, and to effect a surprise it will be necessary to conceal the gun and its detachment in a well-chosen position. Thus we see the three cardinal points for tactical success are--suitable _target_ at close _range_ from a concealed _position_. FIRE EFFECT Napoleon’s maxim, that “fire is everything--the rest is of small account,” is only applicable to the machine gun when the fire is _effective_. Nothing is so useless and wasteful as ineffective machine-gun fire, and the careful study of fire effect and how to obtain the best results is imperative with this weapon. The principles so ably stated in Colonel Mayne’s excellent book, _The Infantry Weapon and its Use in War_, apply almost equally to machine guns, and should be carefully studied by machine gunners, particularly those chapters dealing with the employment of fire in the field. We have already seen that the range of the machine gun is practically the same as that of the infantry rifle, but that the beaten zone is only half the depth and about half the width of the collective fire of infantry, partly owing to the rigidity of the mounting, and partly to the fact that the human error is greatly reduced by being concentrated in the person of a single individual, instead of being spread over some 50 men of varying temperament, nerves, and aiming powers. In addition to these factors, the fire from machine guns is always “collective” and “concentrated” unless deliberately dispersed by the firer, while infantry fire is always “individual” and “dispersed” unless controlled by fire discipline under a leader. Fire discipline and fire control are in the hands of one man--there is no need to point out the target to a scattered firing line, and there is no delay in passing orders down the line, or in the setting of 50 different sights for the correct elevation. Thus fire can be opened far more rapidly and accurately than with rifles, and can be at once directed on a fresh target without ceasing fire, while the effect can be seen by the firer, who can instantly change the rate or cease fire altogether. The beaten zone is perhaps the most important factor in obtaining effective fire, and the following table, compiled from _Musketry Regulations_, 1909, gives the zone beaten by 75 per cent. at four ranges. RANGES