Page:Aircraft in Warfare (1916).djvu/119



§ 49. Rapidity of Fire and its Measure. The measure of the rapidity of gun-fire from an aeroplane or dirigible as an index of its fighting value depends upon the nature of the objective or target. It is evident that in some cases the mere number of projectiles per minute is the most important factor, as, for example, in attacking any object in which a hit is a hit whether the projectile be large or small. In other cases, where the mischief done is in any reasonable relation to the weight of the projectile, the total weight of projectiles discharged per second (or per minute) affords a better criterion. In view of the comparatively flimsy and fragile nature of aircraft, it is doubtful whether the energy equivalent of the discharge will ever be of the importance which it is in the case of the battleship, where the destruction of the enemy depends to a very large extent upon the number of foot-tons with which he is assailed. Thus it is doubtful whether a factor representing the horse-power of the offensive armament would, as applied to the fighting aeroplane, will have any useful significance. Now it is scarcely probable that in the immediate future the fighting-machine can be furnished with complete bulletproof protection, at least such as can be considered effective at short range. Consequently we may take it that it is quite unimportant whether the bullets used in its destruction be of the usual British 215 grains or the