The main principles of aerial warfare are entirely new; in every combat, and in every raid, some precedent is established, some new form or theory of attack is set up. To the airman every day is alike. In times of peace he risks his neck as much as he does in time of war, save that engaged in the latter he has the additional unpleasantness of shell fire. He willingly gives all, but asks for nothing. He is the knight-errant of the twentieth century. In days of the past, it was the cavalryman, wounded and galloping across country, with a hundred foemen hard at his heels, who first brought news of the enemy to the general in command. His was a pleasant occupation, that smacked largely of daring and romance. He stood an excellent chance of getting a bullet through his lungs, or of being clapped into an enemy prison. To-day there comes flying across the heavens a resolute young hero, in a few feet of wood and fabric, throwing defiance to shot and shell alike, suspended thousands of feet up between heaven and earth, peering from that swaying aeroplane at the panorama of the earth beneath. This is the age of science and invention. War on and over the earth, on and under the sea. For many years we have steadily been putting behind us the barbarities of our forbears, we have become more civilized, and, though more civilized, more barbarous. This is no paradox; science has made great and wonderful strides, but science has been more devilishly ingenious than any torture of Spanish Inquisition days. The airmen who pilot their frail craft over hill and valley, sea and land, across cloud and through fog and mist, are the privateers of modern times; but for them there can be no capture, no quarter: only victory or a thousand feet drop to the cruel earth below. Through their young veins must flow the blood of a Drake, of a Philip Sidney, of a Nelson. Theirs must be the courage of a conqueror, the heart of a lion, the nerve of a colossus. No bounded ocean is their sea, but the infinity of space. The ship’s compass is their best friend; for they maneuver their craft like a ship at sea. Wind and weather affect them as they would a mariner. For rock, shoal, sandbank and channel there are the high hills, the tall factory stack, the church steeple, and the deep valley. Landmarks there are, but always below, not on either side. Railways, roads, rivers, fields, woods and hills form the color scheme of the surface of the earth, by which the air pilot steers a course. This, the youngest and most important Service, is essentially one _for_ the young man and _of_ the young man: a Service the future of which is being steadily built up by the “muddied oafs and flanneled fools” of the playing-fields of the public schools of Great Britain.