A point arises as to establishing the identity of an aircraft, when it is sighted during time of war. Machines will fly flags, indicating their nationality, but these flags are not likely to be seen at any great distance. Therefore, if an artilleryman detects an aeroplane, approaching at an appreciable altitude, it will frequently be impossible for him to determine whether it is friend or foe.

That it is, obviously, a machine of a particular type, or make, will not help the artilleryman, because aeroplanes of all forms of construction will be employed, in connection with the various armies. The fact that it may be flying over from behind him, as though it had risen from his own lines, will prove nothing, as a hostile scout might have made a wide detour, and so approached the enemy from the rear.

This difficulty as to identifying friend or foe is likely to prove a real one in time of war, particularly when a large number of machines are in the air; and, exactly how it will be met, is not easy to see.

Having reviewed the position, so far as the aeroplane and gun-fire are concerned, it is possible to form more or less definite conclusions concerning the subject. In the first place, one point is clear: extreme views are unwise in regard to such a problem as this. What tests so far carried out have proved, if they have proved anything, is that there are two points of view.

Artillery experts, who declare that every reconnoitring aeroplane will be blown to pieces before it can carry out its work, are obviously wrong; so, too, is the enthusiast who affirms that guns will be altogether useless when directed against airmen.

What it is possible to deduce, from the generally-inconclusive experiments recorded, is that the balance of testimony—so far as it can be estimated—is in favour of the aeroplane. As a matter of fact, the reasonable view to take is that, when a squadron of aeroplanes deliberately sets forth to reconnoitre an enemy’s position, a certain percentage of machines will be hit by gun-fire, and brought to the ground.

Exactly what that percentage will be is a moot point; experience alone can tell. But the tests already described suggest, very plainly, that the percentage should be low.

The skill of the pilot in avoiding fire will be an important factor in the question—as already mentioned. An over-daring airman may quickly find himself in danger; a careful, cautious man may do all the work required of him without giving hostile artillery a chance to get in a shot.

Level-headed officers, who have practical experience in military flying, do not anticipate, for a moment, that the aeroplanes which ascend in time of war will escape scot-free.

"Casualties there are bound to be." The words are those of an expert of international repute. "Risks will be taken knowingly, according to the value of the information which is required. War is not a kid-glove affair. Large squadrons of aeroplanes will be used; and, apart altogether from the question of the loss of life, the destruction of a small proportion of machines will not affect the utility of a corps. The position, in a nutshell, is this: the news that an aeroplane can obtain is so vitally important that the risk of men, and machines, will be considered amply justified."