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Photo: The Governable Parachute, from Mechanics Magazine, September 25, 1852.

[Goldstone, pp. 8 - 9.] Aerodynamics as a separate science was born in 1799 when an English polymath named George Cayley produced a remarkable silver medallion. Cayley had observed that seagulls soared for great distances without flapping their wings and therefore hypothesized aircraft wings as fixed rather than movable. On the front side of his medallion, Cayley etched a monoplane glider with a cambered (curved) wing, a cruciform tail for stability, a single-seat gondola, and pedals, which he called "propellers," to power the device in flight. On the obverse side of his medallion, Cayley placed a diagram of the four forces that figure in flight: lift, drag, gravity, and thrust. Although powered flight was a century away, Cayley's construct was the breakthrough that the set the process in motion. In 1853, four years before his death, a fixed-wing glider of Cayley's design was the first to carry a human passenger.


Goldstone, Lawrence, Birdmen: The Wright Brothers, Glenn Curtis, and the Battle to Control the Skies, Ballantine Books, New York, 2014.

Revision: 20140326