After this I undertook short flights, taking each officer in turn as a passenger, and keeping within fifty or a hundred feet of the water. At intervals I would make landings on the water, coming down until the float touched the surface, and then getting up again without shutting off the power. When these flights had been made for several days and the men had accustomed themselves thoroughly to the sensation of being in flight, I believed they had progressed far enough to be taken up for longer and higher flights over both land and sea. In these flights I used a machine equipped for landing on both land and water with equal safety. One of the most important things that should be developed in the beginner, and, at the same time, the most difficult, is the sense of balance. Every one who has ever ridden a bicycle knows that the sense of balance comes only after considerable practice. Once a bicycle is under way the balance is comparatively easy, but in an aeroplane the balance changes with every gust of wind, and the aviator must learn to adjust himself to these changes automatically. Especially is a fine sense of balance necessary in making sharp turns. Some aviators develop this sense of balance readily, while others acquire it only after long practice. It may be developed to a large extent by going up as a passenger with an experienced aviator. I have noticed that it always helps a beginner, therefore, to make as many trips as possible with some one else operating the aeroplane. In this way they soon gain confidence, become used to the surroundings, and are ready for flights on their own hook. One by one the officers were taken up as passengers on sustained flights until they felt perfectly at ease while flying high and at great speed. The machine I used for passenger-carrying practice work was capable of flying fifty-five miles an hour without a passenger, and probably fifty miles an hour with a passenger. This speed gave the men an opportunity to feel the sensation of fast and high flying, an experience that sometimes shakes the nerves of the amateur. All this took time. As I have said elsewhere, I did not want to force the knowledge of aviation upon the young officers. Bather, I wanted to let them absorb most of it, and to come by the thing naturally and with confidence. It was much better, as I regarded it, to take more time, and give more attention to the little details, than to sacrifice any of the essentials to a too-quick flight. The men who had been detailed to learn to fly, I assumed, would be called upon to teach other officers of the Army and Navy and, therefore, they should be thoroughly qualified to act as instructors when they should have completed their work at San Diego. This is the view they took also, I believe, and I never saw men more anxious to learn to fly.