LEONARDO da Vinci
(b. 1452, Vinci, d. 1519, Cloux, near Amboise)
Codex on the flight of birds-
Pen and ink on paper, 210 x 150 mm
Biblioteca Reale, Turin
In order to develop his flying machines, Leonardo systematically studied the flight of birds. On this sheet he recorded the observation that birds made use of varying winds when gliding, and he noted this down in small sketches on the margin.