Fol. 7r

Again a wing, described in detail. There can be various versions of the mechanical wing, depending on the number and type of structures for extending the wings and the motion. Leonardo describes the materials for their fabrication, using great quantities of treated leather and silk, emphasising the fact that the flying machine must be as light as possible; metals should be avoided, not only because of weight but also because friction between the various components would impede the fluidity of movement.

«Il predetto uccello si deve, con l'aiuto del vento, sollevare a grande altezza, e questa sarà la sua sicurezza, perché anche quando intervenissero tutti i predetti rivolgimenti, avrebbe tempo di tornare in equilibrio, purché le sue membra siano di grande resistenza in modo che possa opporsi alla forza del vento e alla velocità della discesa, con i detti rinforzi di cuoio e le nervature di seta cruda resistentissima, e non si immagini di poter usare metalli perché essi presto si rovinano nelle piegature o si consumano, per la qual cosa vanno scartati»
(The aforementioned bird, with the assistance of the wind, must be raised to a great height, and this will be the source of its safety, because even when all of the aforementioned disturbances [of air currents] intervene, there would be time to return to equilibrium, as long as its members were strong enough to oppose the force of the wind and the speed of descent, with said reinforcements of extremely resistant leather and the ribs of raw silk. It is not conceivable to use metals because these would soon be ruined where there are bendings, or be eaten away [by rust], so they should be avoided.)

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