Without doubt, these are the fastest vehicles in existence. Many of them can exceed a speed of a hundred miles an hour. Consequently, the pilot lives while he is aloft in the equivalent of a furious gale, and it would seem as if that must produce such a degree of cold as to be almost unendurable. Moreover, it appears that this cold is almost as bad in summer as in winter, for the temperature high up in the air is much the same all the year round. The consequent muffling up with thick clothes and gloves, while it mitigates the cold, must add greatly to the pilot's difficulties in managing his machine. The protection for his eyes and ears which is made necessary by the same conditions must likewise add to his difficulties or at any rate to his discomfort. On the other hand, the effect of gliding at a very high speed over a perfectly smooth track, for that is in effect what it is, is very exhilarating, which to some extent compensates for the other drawbacks. Moreover, the handling of such a machine in the air, particularly if a fight is included in the programme, appeals strongly to the sporting instincts of young men, so much so that during the War, in spite of the dangers and hardships, and the continual loss of life, there was never a dearth of men anxious to become pilots. Owing to these considerations, too, it follows that the best aviators are to be found in those lands where the people are most devoted to sports. Hence, as we have it on excellent authority, the young men of Great Britain and the United States, with their love of adventure and their strong sporting instincts, make better men in the air than the Germans. But really we are more concerned here with the machines than with the men, so let us get back to our subject. The aeroplane consists of one or more "planes" or surfaces which, on being held at a certain slant and then pushed forward rise or remain supported in the air. Therefore the plane or planes need to be supplemented by first a tail and horizontal rudder to hold them at the correct slant, and an engine and propeller to drive them forward. It is not necessary, here, to go over the history of the aeroplane, as that has been told so often. It is not of much interest, moreover, except to those who are particularly concerned with small details of construction, for in a general way the machine of to-day is very little different from one pictured by Sir George Cayley a hundred years ago. It is only the perfecting of the details which has transformed a dream into a very real thing.