Fol. 17r

Codex on the Flight of Birds As he goes into the smallest details of the preceding drawing, Leonardo writes that there are parts to be commanded with the hand and others with the feet. The wing of the flying machine has mechanical joints and parts that are free to move and can be rotated to provide thrust.

«Quando i piedi vogliono calare l'ala "h" la mano "b" con il suo calare alzerà la leva "k" e allora remerà indietro. Quando i piedi vogliono alzare l'ala tu alza subito l'ala in "h" tirando con la mano la leva "g" in su, e allora l'ala resterà di taglio e non sarà impedito all'uccello il suo movimento contro l'aria»
(When the feet want to lower the wing h, the hand b with its lowering will raise lever k and then remain behind. When the feet want to raise the wing, you immediately raise the wing in h, pulling lever g upwards with the hand, and then the wing will remain edgewise and will not impede the bird’s movement against the air.)

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