Clement Ader was a French electrical engineer, who during the last quarter of the nineteenth century devoted a great deal of study and money to the problem of human flight. In his youth he had become interested in the flight of birds, and at a later period had made a study of bats, with a view to imitating their structure in a flying machine. Between the years 1882 and 1890 he built a number of pieces of apparatus, of which the last, finished in 1890, was fitted with a steam engine.

Having exhausted his own resources, he succeeded in enlisting the aid of the French Government, and proceeded to the construction of a large machine, having a steam motor of 40 horse-power. This apparatus was tried under conditions of great secrecy in October, 1897, at the military field at Satory, near Paris, in the presence of a Commission representing the French Government, but the results were so unsatisfactory that the French Government, which had spent more than $100,000 on the project, refused to advance further funds, and Ader abandoned the attempt to solve the problem.