Through the latter part of the last century experiments were carried on with gliders. Among those who achieved much success in this field was the German, Otto Lilienthal, the “flying man,” who made remarkable glides in the early nineties. He would run along the crest of a hill, jump from a precipitous declivity and sail on the wings of his glider over the valley below, guiding his course up and down and from side to side with a rudder attached to the machine. It was his idea that the problem of aviation was to be solved by perfecting the glider so that it could be controlled in its downward flight and then adding a propelling power that would sustain it and lift it through the air.

After the death of Lilienthal by accident in 1896, others continued experiments along similar lines with the same purpose in view. Among these were Octave Chanute and A. M. Herring. They tried at first a monoplane glider and afterward one of five planes. This number they reduced to two. The rudder was made of movable horizontal and vertical blades. It was found that the glider with two planes, the biplane, was most satisfactory.

Herring made for this a compressed air engine and claimed that with this he accomplished a flight of seventy-three feet. There is some doubt, however, as to this claim and some question as to whether it was an upward flight or a downward glide.