Sharpness of vision is imperative. Otherwise the enemy may escape or the aviator himself will be surprised or mistake a friendly machine for a hostile craft. The differences are often merely insignificant colours and details.

America's aviators must be men who will be absolute masters of themselves under fire, thinking out their attacks as their fight progresses.

Experience has shown that the chaser men should weigh under 180 pounds. Americans from the ranks of sport, youth who have played baseball, polo, football, or have shot and participated in other sports will make the best fighting aviators.

CHAPTER VII
SOME METHODS OF THE WAR IN THE AIR

The fighting tactics of the airmen with the various armies were developed as the war ran its course. As happens so often in the utilization of a new device, either of war or peace, the manner of its use was by no means what was expected at the outset. For the first year of the war the activities of the airmen fell far short of realizing Tennyson's conception of

The nations' airy navies grappling in the central blue.

The grappling was only incidental. The flyers seemed destined to be scouts and rangefinders, rather than fighters. Such pitched combats as there were took rather the form of duels, conducted with something of the formality of the days of chivalry. The aviator intent upon a fight would take his machine over the enemy's line and in various ways convey a challenge to a rival—often a hostile aviator of fame for his daring and skill in combat. If the duel was to the death it would be watched usually from the ground by the comrades of the two duellists, and if the one who fell left his body in the enemy's lines, the victor would gather up his identification disk and other personal belongings and drop them the next day in the camp of the dead man's comrades with a note of polite regret.

It was all very daring and chivalric, but it was not war according to twentieth century standards and was not long continued.