Clement Ader was, by all accounts, a brilliant man who taught himself engineering. His interest in aeronautical matters began in earnest in 1870 when he constructed a gas balloon, and later he invented a number of electrical communications devices. He is most well-known, however, for his two remarkable flying machines, the Ader Eole and the Ader Avion No. 3.
Clement Ader claimed that while he was aboard the Ader Eole he made a steam-engine powered low-level flight of approximately 160 feet on October 9, 1890, in the suburbs of Paris, from a level field on the estate of a friend.
He also claimed a flight of some 900 feet in his Avion No. 3 and two witnesses affirmed the event. The Avion No. 3 was a triumph of engineering design derived from nature. Not only did it have an external resemblance to a bat but much of its internal wing structure followed that of the bat, also. To many people, the Ader Eole and Ader Avion No. 3 have become the very symbols of Victorian Era attempts at powered flight.
Ader's claim about his flight in the Avion No. 3 has been largely disproven, although both the Ader Eole and the Ader Avion No. 3 (apparently a rebuilt version of the damaged Ader Avion No. 2) were remarkable machines in many respects and many in France consider him to be the "Father of French Aviation." Clement Ader's most extravagent claims, made late in life, have caused many to reject any claims made by him. In fairness, though, it does seem that he managed to make a short flight at a very low altitude in the Ader Eole that October day in 1890. While the Ader Eole was powered and heavier-than-air, it was not capable of a prolonged flight (due to the use of a steam engine) and it lacked adequate provisions for full flight control.
Link to the Conservatoire National des Arts et Metiers, Paris, France. The Conservatoire National des Arts et Metiers Museum's web site has a number of images of the Ader Avion No. 3, which is on display.