George Cayley established, from 1799, the modern airplane configuration by conceptually separating the functions of lift, propulsion, and control, and identifying the aerodynamic principles that would structure later aeronautics. His 1799 silver medal already shows the modern fixed-wing force diagram. His publications from the first third of the 19th century turned heavier-than-air flight into a problem of rational engineering a century ahead of Kitty Hawk.