There has, from the earliest days of battle, been a need for scouting—a need for news as to what the enemy is doing. Picture two armies about to engage. They approach each other cautiously, troops spread out and dotted here and there; while in front of each force is thrown a screen of outposts. These form a protective fence, through which the scouts of the enemy find it difficult to penetrate. What the scouts seek to discover is how many men there are in the army moving forward, how many guns, and how these men and guns are being massed and drawn up for the battle that impends. But the outposts head them off and shoot them down; and as both armies have outposts, and as both sets of scouts find the same difficulty in obtaining news, the two forces may grope and blunder into battle without knowing such facts as to numbers and positions as might spell the difference between victory and defeat. Of course, the scouts do their best, some on foot, some horsed; but it was Napoleon who wrote:
“Nothing is more contradictory, nothing more bewildering, than the multitude reports of spies or of officers sent out to reconnoitre. Some locate army corps where they have seen only detachments; others see only detachments where they ought to have seen army corps.”
But now came the aeroplane, and strategists seized the opportunities it offered. Outposts could do nothing against such a scout as this; instead of seeking to dodge them through a wood, or round a hill, it could pass thousands of feet above their heads; and the earth below, as viewed by the spy sitting in his machine, would be spread out like a panorama; he would see the troops of the enemy in motion, and note their strength and the positions to which they moved. No wonder the War Departments of Europe were ready to buy aeroplanes. Buy them they did, indeed, in growing numbers; but the drawback of the early machines was that they were fair-weather craft; they would not fly in winds. Imagine that a battle impends, and that the Commander-in-Chief of one army seeks news as to the movements of some division of his enemy; so he orders the air-scouts to ascend. But the wind may be blowing hard; and if it is, and the aeroplanes are only fair-weather machines, they will have to remain on the ground till the wind drops, and perhaps miss their greatest chance during a whole campaign.
But it was astonishing how, feeling greater confidence in the handling of their machines, airmen began to join issue with this enemy the wind. They were helped, too, by a growing efficiency in the construction of their craft. Machines were built more strongly, engines were more staunchly made; in all details that spelt reliability, were aircraft improved. But the wind, none the less, took its toll. It was not combated without loss of life; and we find that, before the end of 1910, nearly thirty men had been killed while flying. In many cases, struck by a heavy gust, a machine collapsed in flight; in others, beaten over by the force of the wind, but with his craft intact, the pilot had fallen to earth, powerless to regain the control of his machine.
PLATE IX.—THE FIRST HIGH-POWERED BLERIOT.
This type of monoplane, in which Mr. Grahame-White learned to fly—being seen with a passenger above—was built by Bleriot for the speed contests at Rheims in 1909. It had an 80-h.p. motor, as compared with the 25-h.p. engine which was then fitted to ordinary Bleriots, and attained a speed of 60 miles an hour.
In wind-flying there were these two distinct dangers: a man might be dashed to earth by a gust when rising or descending; or he might be struck by a rush of wind when at a considerable height, and find his craft driven over until it began to slip sideways instead of flying forward. In “side-slips,” as they are called, there lies a grave risk. What happens is this. A man flying in a wind may, by vigorous use of his ailerons, recover the balance of his machine time after time; but as the wind rises, he may be struck ultimately by a gust that tilts his planes to an abnormal angle, despite his efforts to check them. The machine will then heel till it stands almost vertical—till it reaches such an angle, in fact, that it ceases to move forward and begins to slip sideways—skidding away, beyond the pilot’s control, like a motor on a greasy road. How an abnormal gust may cause a side-slip is illustrated by [Fig. 53].