Sir George Cayley

Source: an article from Grace's Guide
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Sir George Cayley, 6th Baronet (1773-1857) "Father of Aerodynamics" was a prolific English engineer from Brompton-by-Sawdon, near Scarborough in Yorkshire.

1773 December 27th. Born on in Scarborough, Yorkshire, the only son of Sir Thomas Cayley (1732–1792), and his wife, Isabella Seton (d. 1828); there were also four daughters.

He was a pioneer of aeronautical engineering, though he worked over a century before the development of powered flight. He served for the Whig party as Member of Parliament for Scarborough from 1832 to 1835, and helped found the 'Royal Polytechnic Institution' (now University of Westminster), serving as its chairman for many years. He was a founding member of the British Association for the Advancement of Science and was a distant cousin of the mathematician Arthur Cayley.

Cayley inherited Brompton Hall in 1792 and its estates on the death of his father, the 5th baronet.
1795 July 9th. Married Sarah (d. 1854), the daughter of his first tutor, the Revd George Walker; they had three sons and seven daughters, of whom three children died young.

He engaged in a wide variety of engineering projects. Among the many things that he developed are self-righting lifeboats, tension-spoke wheels, the "Universal Railway" (his term for caterpillar tractors), automatic signals for railway crossings, seat belts, small scale helicopters, and a kind of prototypical internal combustion engine fuelled by gunpowder. He also contributed in the fields of prosthetics, air engines, electricity, theatre architecture, ballistics, optics and land reclamation.

He is mainly remembered for his flying machines, including the working, piloted glider that he designed and built. The discovery of cartoons in Cayley's school notebooks (held in the archive of the Royal Aeronautical Society Library in London, England) reveal that even at school Cayley was developing his ideas on the theories of flight. It has been claimed that these images indicate Cayley having modelled the principles of a lift-generating inclined plane as early as 1792. To measure the drag on objects at different speeds and angles of attack, he later built a "whirling-arm apparatus" - a development of earlier work into ballistics and air resistance.

He also experimented with rotating wing sections of various forms in the stairwells at Brompton Hall. These scientific experiments led him to develop an efficient cambered airfoil and to identify the four vector forces that influence an aircraft: thrust, lift, drag, and gravity. He discovered the importance of dihedral for lateral stability in flight, and deliberately set the centre of gravity of many of his models well below the wings for this reason. Investigating many other theoretical aspects of flight, many now acknowledge him as the first aeronautical engineer.

By 1804 his model gliders appeared similar to modern aircraft: a pair of large monoplane wings towards the front, with a smaller tailplane at the back comprising horizontal stabilisers and a vertical fin.
1804 He began experiments on the lifting properties of aerofoils. His aim was to learn enough aerodynamics (the word itself was not in use until 30 years later) in order to build himself a flying machine. In order to obtain systematic data on the lifting power and the weight of various wings, he measured and weighed many representative birds and then undertook a series of tests using an aerofoil on a whirling arm. His results showed a remarkable correspondence with modern theory of aerofoils at low angles of incidence. Caley followed these tests by building and flying the first known model glider, which flew but the results were not fully comprehensible to Caley.

1808 He built a larger model glider.

1838 George Cayley, Bart., of Yorkshire, became a member of the Institution of Civil Engineers.

At some point prior to 1849 he designed and built a triplane powered with 'flappers' in which an unknown ten-year-old boy flew.

1853 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 1853. The first adult aviator has been claimed to be either Cayley's coachman, footman or butler: one source (Gibbs-Smith) has suggested that it was John Appleby, a Cayley employee - however there is no definitive evidence to fully identify the pilot.

1857 December 15th. Died at Brompton Hall, and was buried at Brompton church