Last of all come the single-seaters, whose sole purpose is to fight. Many different types have been tried--monoplanes, biplanes, and triplanes, with different kinds of fixed and rotary motors. At present the biplane seems to have it (though I have seen an experimental monoplane that is a terror), as the monoplane is by nature too weak, and the triplane (magnificent otherwise!) is too slow in diving for either attack or escape.
The work the different groups perform seems to be roughly the same in the Allied and enemy armies. The day-bombers fly at great heights, sometimes escorted and protected by single-seaters. The night-bombers fly fairly low, never escorted. Photographers, observers, and artillery regulators have a nasty job, as they must fly rather low, constantly subjected to a galling attention from old Archibald. When their mission requires it, they are escorted by chasse machines--a job that single-seater pilots do not pine for, because they often go twenty or thirty miles into "Bochie," where motor-trouble means a soup diet till the end of the war; and because, at low altitudes, hovering over a slow "cuckoo," the anti-aircraft gunners have too good a time.
The single-seaters may be divided into two classes: the first does escort work about half the time, the second does nothing but parade up and down the lines, hunting for trouble. The last are the élite among airmen. Unfortunately I am not one of them, as they are recruited only from tried and skillful pilots. As to fighting, there is a good deal of popular misconception. One imagines picturesque duels to the death, between A (the great French or English ace) and X (his German competitor)--the multitude of straining, upturned eyes, the distant rattle of shots, the flaming spin of the loser. As a matter of fact, a duel between two monoplaces, handled by pilots of anything like equal skill, who are _aware of each other's presence_, is not unlikely to end without bloodshed. Bear in mind that they can shoot only forward, that the gun must be aimed by aiming the whole machine (to which it is fixed immovably), and that a twisting, climbing, banking aeroplane, traveling at over one hundred miles per hour, is no joke to hit in its small vitals, and you can see that this must be so.