Cayley's aerial carriage. Design for an aerial carriage, published in 1843 by the British engineer George Cayley (1773-1857). This is a biplane 'convertiplane', using a set of four rotating blades (for vertical lift) that could be converted into fixed wings (for forward flight), and two propellers. Cayley's main work, though, was on his gliders. In around 1808, he built and flew a large unmanned glider, thought to be the first heavier-than-air machine ever flown. Much later, in 1853, his coachman flew one of his gliders across a valley, in what was the first manned glider flight. Diagram from Mechanics Magazine (1843).