Soon afterward the student went up with an instructor for a long flight. The purpose of the flight was to get the pupil used to higher altitudes and to the motion of the aeroplane, and to give him a chance to watch his teacher actually running the machine. Strange to relate, many who have felt an uncontrollable desire to jump off high buildings have no such feeling while in an aeroplane. That is because they sit and look out horizontally instead of perpendicularly downward, and because they move at such tremendous speed. After several trips of that kind, the instructor let the student handle the controls until he could climb, dive, and “bank,” or turn the machine in the air. But the pupil was not permitted to land a machine until near the end of his course; for next to getting out of a tail spin, a dive, or a side slip, landing was the hardest task in flying. Statistics show that more aviators have been killed in making landings than in any other way. Many of the accidents, of course, were caused by the nature of the ground, for when the engine of the aeroplane stops, the aviator has to volplane or glide down wherever he can. One of the difficulties of landing is owing to the fact that even training-machines cannot land at a slower speed than thirty-five miles an hour. If the wheels of the aeroplane, when they first touch ground, do not skim over the surface of the field, the machine is liable to “nose in” and turn a somersault. Indeed, that is why the pusher type of training-machine, with the propeller in the rear of the pilot, is being abandoned for the tractor machine, which has the propeller in front. If an accident does occur with a tractor the engine does not “climb your back.” One of the greatest dangers of flying a seaplane is due to the fact that the engine is installed not in the hull but high above the aviators’ heads, upon which it is apt to fall in case of a crash. The student was next permitted to fly alone. Most machines were so strongly built that accidents were seldom caused by breakage, although, of course, before each flight the aviator and his mechanic critically examined his machine for broken parts. With a reasonable amount of care straight flying by daylight was comparatively safe. In the French aviation schools, before the military birdman could pass his final examinations, he had to climb twice to an altitude of six thousand feet and spend an hour at a ten-thousand-foot altitude. If he passed that test successfully, he had to fly over a triangular course of one hundred and fifty miles and land at each corner of the triangle.