Da Vinci Notes 15: The Flight of Birds
A bird is an instrument working by mathematical law. On the hill above Florence in 1505 I watched the kite balance its weight against the air and asked whether a man could learn it.
Leonardo's 1505 Codex on the Flight of Birds: the kite, its centre of gravity and centre of resistance, gliding, the cradle memory and the great bird prophecy.


by Marie Curie 