Fol. 16r

On this page Leonardo draws and describe the first air bag in history, a system that he invented to protect the pilot should he fall. In the lower part of the drawing, eight oval elements represent wineskins, actually filled with water, which, above, we see wrapped around the pilot’s body in the cockpit-cage. Above, the flying machine hovering in the air. The unknown object shown below may be the kite’s prey. Leonardo observes that birds use only a part of their strength to fly, and that they are capable of lifting prey that weighs as much as they do. Therefore man too is capable of relying on his own strength for flying, even if he has to use more of his strength than birds do of theirs.

«Anche l'uomo ha nelle gambe una quantità di forza maggiore di quanta se ne richiede per il suo peso, e per provarlo metti in piedi un uomo sopra la sabbia e osserva di quanto sprofondano i suoi piedi, ponigli addosso un altro uomo e verifica di quanto più è sprofondato, poi togli l'uomo dalle sue spalle e fallo saltare più in alto che può, e vedrai che l'impronta dei suoi piedi è più profonda dopo il salto che quando aveva l'uomo addosso, il che prova in due modi che l'uomo ha forza almeno doppia di quella richiesta per sostenere il suo peso»
(Man too has in his legs a quantity of strength that is greater than that required for his weight; to prove this, set a man on his feet in the sand and observe how deep his feet go into it, then put another man on top of him and verify how much deeper he goes, and then take the man off his shoulders and make him jump as high into the air and he can, and you will see that his footprints are deeper after the jump than when he had the man on top of him. This proves in two ways that man has at least twice the strength of that required to support his weight.)

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