way and that to secure the desired effect from the warping of the wings. 'For the sake of simplicity,' says Wilbur Wright, 'we decided to attach the wires controlling the vertical tail to the wires warping the wings, so that the operator, instead of having to control three things at once, would have to attend to only the forward horizontal rudder and the wing warping mechanism; and only the latter would be needed for controlling lateral balance.' The thing was done. They had built an aeroplane that could fly; and the later introduction of an engine was as simple a matter as the harnessing of a horse to a carriage. 'With this apparatus', says Wilbur Wright, speaking of the glider of 1902, 'we made nearly seven hundred glides in the two or three weeks following. We flew it in calms and we flew it in winds as high as thirty-five miles an hour. We steered it to right and left, and performed all the evolutions necessary for flight. This was the first time in the history of the world that a movable vertical tail had been used in controlling the direction or the balance of a flying machine. It was also the first time that a movable vertical tail had been used, in combination with wings adjustable to different angles of incidence, in controlling the balance and direction of an aeroplane. We were the first to functionally employ a movable vertical tail in a flying aeroplane. We were the first to employ wings adjustable to respectively different angles of incidence in a flying aeroplane. We were the first to use the two in combination in a flying aeroplane.' It is a large claim, and every word of it is true. New inventions are commonly the work of many minds, and it would be easy to name at least half a dozen men to whose work the Wrights were indebted. But these were tributaries; the main achievement belongs wholly to the Wrights. Their quiet perseverance, through long years, in the face of every kind of difficulty, is only a part of their distinction; the alertness and humility of mind which refused all traffic with fixed ideas, and made dangers and disappointments the material of education, is what stamps them with greatness. They put themselves to school to the winds. They knew that there is no cheap or easy way to master nature, and that only the human spirit, at its best and highest, can win through in that long struggle. Their patience never failed. 'Skill', says Wilbur Wright, 'comes by the constant repetition of familiar feats rather than by a few overbold attempts at feats for which the performer is yet hardly prepared.' Man must learn to fly as he learns to walk. 'Before trying to rise to any dangerous height a man ought to know that in an emergency his mind and muscles will work by instinct rather than by conscious effort. There is no time to think.'