THE IDEA OF THE PARACHUTE is conventionally attributed to Leonardo da Vinci, who in 1485 sketched a pyramid-shaped canopy attached to a wooden frame, with a pole from the apex and cords from the corners to which a person could hang on. Its purpose was to enable anyone to let themselves down from a height without danger; its particular application would be to persons escaping from buildings on fire. But Leonardo's design stayed unpublished until the end of the nineteenth century, and although some early experiments by Joseph Montgolfier made use of the idea of using resistance to slow descent in air in ways common both to balloons and parachutes, the development of parachutes as separate entities proceeded slowly. There were successful tests at Avignon, it was said, using first a sheep, then a condemned prisoner.

Inspiration – and explanation – came from the umbrella, commonly in use as a protector against rain. In October 1784, Thomas Martyn published a design for a globe balloon that explicitly included an ‘Umbrella to afford easy descent’ should the balloon burst. It was dismissed by Blanchard, who said Martyn was welcome to take what little credit there was in such a useless device. Despite this fart in Martyn's general direction, Blanchard was himself experimenting with designs of ribs attached to a silk canopy, and by June 1785 he was making test drops above his Aerostatic Academy in Vauxhall. One was to have starred a sheep – but just as the balloon launched, a lady tripped over the cords which connected sheep and parachute to the balloon, which shot off and burst.