Fol. 1r and Fol. 1v

Codex on the Flight of Birds of Leonardo The order of the folia does not correspond to that of the text of the Codex, which constitutes the first scientific study on flight in the history of science. It is very likely that Leonard began to annotate his observations on flight at the end, while the first folia are a recap of knowledge regarding statistics and dynamics, the theoretic basis on which he later built his theory of flight.
Fol. 1 r
Codex on the Flight of Birds of Leonardo In the drawing on the upper right part of fol. 1v Leonardo notes the different speeds of a falling body according to the trajectory following an arc or a chord.
Fol. 1 v

«Quando il polo della bilancia sarà di minor estensione, tanto il suo movimento sarà di minor ampiezza. Quanto la bilancia è più lunga, tanto è di minor oscillazione perché il polo, a tanta lunghezza, viene a essere più sottile che alla bilancia corta…Sempre la cosa leggera sta sopra la pesante essendo in libertà l'una e l'altra. La parte più pesante di un corpo si fa guida alla più leggera»
(The less the arm of the scale is extended, the less ample its movement. The longer the scale, the shorter its oscillation, because when the arm is of great length, it becomes thinner than that of the short scale. … The light thing always remains over the heavy one, when both are unrestrained. The heavier part of a body acts as a guide for the lighter part.)

NOTE. For each page of Leonardo’s Codex we provide a brief summary, with the quotation of one that page’s most significant passages edited in modern Italian, with an English translation.

translation by Kim Williams