English engineer Sir George Cayley published a three-part paper, "On Aerial Navigation," In the Journal of Natural Philosophy, Chemistry and the Arts, 24 (1809) 164-174; 25 (1810) 81-87, 161-173, with single engraved plates in Vol. 24 and in Vol. 25 relating to the paper. The papers were published in issue numbers 108, 112, and 113.
Cayley founded the science of aerodynamics and is generally credited with the invention of the airplane. He has also been called the world's first aeronautical engineer. Cayley discovered and identified the four aerodynamic forces of flight—weight, lift, drag and thrust— and in 1799 took the crucial step of separating the system of thrust from the system of lift. This enabled him to break away from the centuries-old preoccupation with flapping-wing machines (ornithopters), and to conceive and design a fixed-wing machine with cruciform tail-unit, propelled by paddles— the first modern-configuration airplane. In 1804 he flew the first of his successful model fixed-wing gliders and became the first to explore the aerodynamical possibilities of a whirling arm.
Cayley's researches first appeared in print in "On Aerial Navigation," which includes his classic pronouncement that "the whole problem [of aerodynamics] is confined within these limits, viz. to make a surface support a given weight by the application of power to the resistance of air."
Gibbs-Smith, Invention of the Aeroplane 1799-1909 (1966) 5-9. Hodgson, The History of Aeronautics in Great Britain. . . (1924) 345-349. Carter & Muir, Printing and the Mind of Man (1967) no. 263. Hook & Norman, The Haskell F. Norman Library of Science and Medicine (1991) no. 423.