Especially helpful to the Wright brothers were Octave Chanute, a civil engineer, builder of bridges, railroads, and gliders and Samuel Pierpoint Langley, astronomer and head of the Smithsonian. Langley, with help of Smithsonian funding, had helped create a pilotless "aerodrome."
Other experimenters in controlled flight were Sir George Cayley, Sir Hiram Maxim, Alexander Graham Bell, and Thomas Edison. In France the government spent a considerable amount of money on a steam-powered flying machine built by Clement Ader, who gave the word avion, airplane in English, to the French language. Along with the cost of experiments, the risk of failure, injury, and death, there was the inevitable prospect of being mocked as a crank, a crackpot, often for good reason. The experimenters served as a continual source of popular comic relief.
Among the material supplied by the Smithsonian to the Wright brothers was Pierre Mouillard's Empire of the Air, which exalted the wonders of flying creatures. Wilbur took up bird watching on Sundays, observing what Mouillard preached. The dreams of Wilbur and Orville had taken hold. They would design and build their own experimental glider-kite, building on what they had read, observed of birds in flight, and spent considerable time thinking. They became familiar with aeronautical terms such as equilibrium, lift, pitch and yaw. Equilibrium was all-important to them. Wilbur's observations of birds and how they adjusted their wings to maintain balance inspired him to the idea of building a glider with "wing warping" or "wing twisting." This made an immensely important and original advance to their goal.