Disregarding the crude essays at human flight, recorded in the early histories and liter ature of many peoples, we may notice first the well-authenticated sketches of Leonardo da Vinci. His fertile mind conceived three dis tinct devices for carrying a man in the air. But he and his successors for nearly four cen turies could do little more than invent. For lack of motive power they could not navigate dynamic fliers, however ingeniously construct ed. Da Vinci's first design provided the oper ator with two wings to be actuated by the power of both arms and legs. His second de sign was a helicopter; an aerial screw 96 feet in diameter was to be turned by a strong and nimble artist who might, by prodigious effort, lift himself for a short time. His third scheme of flight was a framed sail on which a man could ride downward, if not upward.
Mr. Henry Woodhouse, one of the foremost aeronautic authorities, author of the 'Textbook of Naval Aeronautics,' and the 'Text book of Military Aeronautics,' has summarized the work of pioneer experiments in aeronautics as fol lows: History has a list of some two-score of experimenters who tried to develop power flight, among whom were : Sir George Gay ley, an English inventor, whose writings 10) show that he was first to plan dynamic flight on a scientific basis. He planned an aeroplane built with slightly oblique planes, resting on a wheeled chassis, fitted with propel lers, motors and steering devices. Samuel Henson, another English inventor, in 1843, patented what was designated as an steam carriage,( an aeroplane of immense size, which was to be used for passenger carrying. This carriage was never built. Another Eng lish scientist, F. H. Wenham, improved on Henson's idea, and in 1867 developed a multi plane. This model was taken up by another inventor, M. Strongfellow, who reduced the number of planes to three, making a triplane, *Por a detailed discussion see AEROPLANE.
which he fitted with a tail and two propellers. This model was shown at the exhibition of the Aeronautical Society of Great Britain in 1868. As in the case of previous inventors, nothing in this model indicated that he had any com prehension of the principles of stability or knowledge of the lifting capacity of surfaces, or of the power required for dynamic flight. Strongfellow deserves, however, much credit for building a very light motor, one of sufficient lightness to support a well-designed aeroplane. In 1872, a French inventor, named Alphonse Penaud, constructed a small monoplane. It was only a toy— two flimsy wings, actuated by a twisting rubber, but had fore-and-aft stability, something that most of the creations of the time lacked. Subsequently, in 1875, Penaud took
out a patent on a monoplane fitted with two pro pellers, and having controlling devices. But this was not built, principally because it would have required a light motor, and the lightest available at the time weighed over 60 pounds per horse power, or 20 times the weight of the motors of to-day. Louis Pierre Mouillard, a Frenchman, having observed that large birds in flight, while seeming at rest, could go for ward against the wind without a stroke of the wings, constructed a number of gliders, built on the principle of bird wings, and experi mented with gliding. In 1881, he published a valuable work entitled
Pioneers of Modern These early experimenters laid the foundations of modern aviation. They showed the supporting power of their rigid surfaces, defined the gen eral shape and structure of the aeroplane, and prepared the work for the next generation, which was to perfect these, and find ways and means to make the aeroplane rise from the ground and maintain equilibrium in the air. This new generation came toward the close of the 19th century. These new men, the pioneers of modern aviation, were divided into two schools. The first sought to achieve soaring flight by means of kitelike apparatus, which enabled them to soar in the air against winds, their machines being lifted up and supported by the inertia of the air as kites are. The second sought to develop power flight, that is, to send their kitelike machines through the air at high speed, being tracted or propelled by revolving. screws actuated by motor power. The most eminent experimenters in the first schools were Otto Lilienthal, who was the chief ex pounder of gliding flight; P. L. Pilcher, an English follower of Lilienthal ; Octave Chanute, an American follower of Lilienthal, and J. J. Montgomery, an American experimenter. Lilienthal, a German, was the first to make gliding flight a science, and he first defined the value of arched wings, and the amount of pressure to be obtained at various angles of incidence. He met with untimely death while experimenting in 1896. Chanute's experiments were in the line of Lilienthal, but his great contribution was his early encouragement of the Wrights, although the Wrights did not suc ceed by adopting Chanute's theories.