In the Wilbur Wright lectures we commemorate, and pay our tribute to, that pioneer work upon which the art of flying is founded and it is only now that carrying our minds back to those early days we see how thorough were the methods which led to success. The work of Lilienthal in gliding with curved wings—brought to an untimely end through lack of control—had shown that the secret of success was to be found in free flight experiment. Then came the great contribution of the Wrights, who discarded Lilienthal's acrobatic control and carrying through the whole modern programme of wind tunnel research, detail design and construction, found out by practical flying that essential feature of control which has been used in practically every aeroplane that has been flown.
In the original Wright aeroplane, as in all its successors of fixed wing area, the only means used for varying the lift was by alteration of the angle of incidence or of the camber of the wing either by warping or by the equivalent use of ailerons.