power of rapidly putting on altitude alone form its natural and most appropriate means of defence. The tactical scout is not in the same position; its duties are of such a character that if it be driven by hostile aircraft away from its place of operation, it has for the time being ceased to fulfil its mission, and so either it must always operate with a protective force of fighting machines within call, or it must itself be armed, and be rendered capable of putting up a fight. In any case the tactical scout or machine for local reconnaissance will require to be furnished, to some extent at least, with both offensive and defensive armament. But it is by no means clear that it will require to be armed more heavily than may be sufficient to hold its own with the aircraft of the enemy engaged on similar duty, or than required to enable it to perform the minor acts of aggression against the enemy's land forces that fall to its lot.
Evidently it can be only a matter of time before the specialised fighting-machine is called into being. We may admit that the first and more immediate step will be to render the tactical reconnaissance type capable of taking the offensive, so that it may establish its ascendency over the similar craft of the enemy. But the struggle for supremacy in the air which must then ensue will call imperatively for something more powerful and efficient, a specialised and heavily-armed fighting-machine in fact. It is this type, the fighting machine of the future, that the author proposes to make the subject of present study, discussing primarily the factors upon which its armament and its usage, or tactical employment, depend. It may be taken that for the period during which the tactical scout is playing the double rôle of reconnaissance-machine and fighting-machine the main general considerations will apply.
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