Entitled: "Design drawing for a man-powered flying machine designed by Sir George Cayley." George Cayley (December 27, 1773 - December 15, 1857) was an English engineer and one of the most important people in the history of aeronautics. Many consider him the first true scientific aerial investigator and the first person to understand the underlying principles and forces of flight. Often known as "the father of Aerodynamics", he was a pioneer of aeronautical engineering. The model glider successfully flown by Cayley in 1804 had the layout of a modern aircraft, with a kite-shaped wing towards the front and an adjustable tailplane at the back consisting of horizontal stabilizers and a vertical fin. A movable weight allowed adjustment of the model's centre of gravity. At some time before 1849 he designed and built a biplane in which an unknown ten-year-old boy flew. Later, with the continued assistance of his grandson George John Cayley and his resident engineer Thomas Vick, he developed a larger scale glider (also probably fitted with flappers) which flew across Brompton Dale in front of Wydale Hall in 1853.