Cayley Governable Parachute

Sir George Cayley, a Yorkshire baronet who lived at Brompton Hall near Scarborough, was the first person to set out how an aeroplane works. In 1799 he engraved a small silver disc with a design that separated lift from thrust: a fixed wing to hold the machine up, a tail to steer and stabilise it, and some separate means of pushing it along. In his paper On Aerial Navigation of 1809–10 he described the forces on a wing and the value of a cambered surface and dihedral for stability, and he tested his ideas with models and with gliders on the slopes around Brompton.

An engine light enough to fly did not exist in his lifetime, so he worked on gliders. In 1849 a triplane glider carried a boy a short distance down a hill. In 1852 the Mechanics’ Magazine published his design for a ‘governable parachute’: a single kite-shaped sail stretched over a wooden frame, set at a slight angle above a boat-shaped car on three wheels, with a fixed tail and a second tail the pilot could move with a tiller to steer. In 1853 a man-carrying glider was flown across Brompton Dale, the small valley behind the hall.

No drawing of the 1853 glider survives: it may have followed the governable parachute, or been closer to the triplane of 1849 with the new wing. The only account of the flight came decades later from Cayley’s granddaughter, who had watched it as a girl of about nine. She called the man aboard Cayley’s coachman, and remembered that on landing he asked to give notice, because he had been hired to drive and not to fly; the historian Charles Gibbs-Smith thought he was probably Cayley’s groom, John Appleby. Cayley died in 1857, half a century before powered flight, but the Wright brothers later acknowledged how much he had worked out. Two full-size replicas built to the published governable parachute design are in Yorkshire museums: one at the Yorkshire Air Museum at Elvington and one at the South Yorkshire Aircraft Museum in Doncaster.