Clément Ader, (2 April 1841 – 3 May 1925) was a French inventor and engineer who was born in Muret, Haute-Garonne (a distant suburb of Toulouse), and died in Toulouse. He is remembered primarily for his pioneering work in aviation 1).
Ader was an innovator in a number of electrical and mechanical engineering fields. He originally studied electrical engineering, and in 1878 improved on the telephone invented by Alexander Graham Bell. After this he established the telephone network in Paris in 1880. In 1881, he invented the théâtrophone, a system of telephonic transmission where listeners received a separate channel for each ear, enabling stereophonic perception of the actors on a set; it was this invention which gave the first stereo transmission of opera performances, over a distance of 2 miles (3 km) in 1881 2).
Following this, he turned to the problem of mechanical flight and until the end of his life gave much time and money to this 3)..
Ader's progress with aircrafts attracted the interest of the minister of war, Charles de Freycinet. With the backing of the French War Office, Ader developed and constructed the Avion III. It resembled an enormous bat made of linen and wood, with a 15 m (48 ft) wingspan, equipped with two four bladed tractor propellers, each powered by a steam engine of 30 hp (22 kW).
See for more information: Avion n° 3.