This gliding apparatus is not unlike that with which M. Chanute and other early experimenters tested the qualities of air currents. The apparatus here shown is being drawn by an automobile, so that its action is virtually that of a kite. This picture was taken at Morris Park, New York, in 1909. The descent was made too abruptly and the aviator was seriously injured.] The great German scientist, Helmholtz, after years of careful study, finally reached the conclusion that man would never be able to fly by his own power alone. But, as we have seen, Professor Langley had shown that in these mysterious questions pertaining to flight even a Newton could be wrong; and why not Helmholtz? Otto Lilienthal, also a German, thought that his fellow-countryman _was_ wrong. For years he had made a study of the flight of birds, and his studies had led him to the same conclusions that have usually been reached by every student of the subject, both before and since--that soaring flight, without any flapping movement, is possible under certain conditions; that curved surfaces can acquire a horizontal motion by the action of the wind alone, "when their curvature bears a certain relation to their superficies"--in short, a relation represented exactly by the wings of birds. It was not supposed by Lilienthal, or by any of the members of the school of aviators, that simply by making a device that reproduced the proportions and shape of a bird any person might mount and fly. But it was believed that, given such a device, a man might learn to fly with practice. Lilienthal, therefore, constructed a flying-machine with correctly curved surfaces made of linen stretched over a light wooden frame, the total area being about fourteen square yards, and the whole machine weighing only about forty pounds. In the center was an aperture where the operator was stationed, holding the frame in position by his arms. Obviously, as no flapping motion in imitation of a bird's wings was possible, some other means of giving the necessary impetus for horizontal flight was necessary, and here again the study of birds suggested a method.