Sir George Cayley's Patent Universal Railway, 1826.
© Science Museum / Science & Society Picture Library
Illustrated plate from 'The Mechanics' Magazine, (28 January 1826), showing a 'vehicle formed by two endles chains'. Cayley (1773-1857) was a pioneer of aerial navigation, the founder of aerodynamics, and is widely considered to be the 'father' of fixed-wing flight. This vehicle was the forerunner of the caterpillar tractor.