The machine gunner may be likened to the fireman with his hose-pipe, whose object is to bring the base of his jet of water to play on a certain spot some distance away from the nozzle of his pipe. He does not trouble about the distance, he does not require to know the range; but pointing the nozzle in the direction of the spot he desires to strike, he elevates or depresses it until he observes the base of the cone of water falling on the right spot, and then he holds his pipe so that it continues to fall where he desires; he does not trouble about the smaller streams and drops of water that fall short or go beyond, but devotes his whole attention to keeping the nucleus of the stream--the 75 per cent. or 50 per cent. zone--falling on his “target.” In precisely the same way the machine gunner must look upon his stream of bullets as a stream of water from a hose-pipe, and his object must be to cause the centre of that stream to play on the target, or, in other words, to bring the effective cone of fire on the target so that it is the centre of the beaten zone. This can be done by “observing” the strike of the nucleus of the shots and altering the elevation accordingly. On favourable ground fire can be observed by No. 1 up to 800 yards, but No. 2 with the aid of good glasses can observe fire on favourable ground up to 1,500. This observation of fire is the best method of obtaining the correct elevation at “effective” ranges (_i.e._ 1,400 to 600), if the ground is suitable. The procedure should be as follows: The range should be “estimated” by No. 1, who should then adjust his sight for 100 or 200 yards less elevation than the supposed distance, and fire “groups” of 8 or 10 shots; No. 2 observing the strike of the bullets and saying “short” or “over,” as the case may be, while No. 1 alters the elevation between each group until No. 2 says “on,” when fire may be continued, still observed by No. 2, until the desired effect has been attained. No. 1 must be careful to fire his first group of shots short of the target, as they are much easier to locate than shots which fall “over.” If the target is only visible for a short time, the groups may be “rapid,” but as a rule “deliberate” fire at the quickest rate should be used, and “rapid” only used when the range has been found. If the ground is not favourable for the observation of fire, or the range is too great, this method cannot be used, and it will be necessary to obtain the range by instruments; but it will not always be possible to do so, and it is necessary to find some other reliable way of ensuring that the target is within the “effective” zone.