Jane's All The World Aircraft 1913

DE LA HAULT Adhemar de la Hault, 214 rue Royale, Brussels. In 1906, built a flapper of novel design. This was followed in 1910, by a machine on monoplane lines with one fixed plane and two flapping wings. This failed to fly, and in August, 1911, was altered into a biplane. It did not succeed, however. M. Hault is still pursuing the ornithopter question.

Журнал Flight

Flight, March 27, 1909

FLYERS AT OLYMPIA.

De la Hault (MIESSE).

  The flapping wing flyer for which Messrs. Miesse have the British concession is a machine of very peculiar construction. The wings consist of a pair of fabric-covered blades which are mounted on trunnions and are articulated through ball and socket connections by a pair of spur wheels which in turn are operated by a system of gearing from an engine which is placed on a lower level and with its crank-shaft vertical. The relative position of the ball socket joint to the trunnion which carries the paddle is such that the rotation of the gear wheel causes the paddles to perform downward beat followed by a feathering motion, but although this has the appearance of a rowing stroke there is no propulsive effort, for such forward drive as there might be is neutralized by a retarding period immediately preceding the downward beat. We are informed that this machine has actually lifted itself in the air for a period which was only brought to a conclusion because the gear wheels gave way.