If a man has a tent made of ...

If a man has a tent made of linen of which the apertures have all been stopped up, and be it twelve bracchia across (over twenty-five feet) and twelve in depth, he will be able to throw himself down from any height without sustaining injury. [His concept of the parachute.]
If a man has a tent made of linen of which the apertures have all been stopped up, and be it twelve bracchia across (over twenty-five feet) and twelve in depth, he will be able to throw himself down from any height without sustaining injury. [His concept of the parachute.]

Quotes from the same author

All our knowledge has its origins in our perceptions.
It had long since come to my attention that people of accomplishment rarely sat back and let things happen to them. They went out and happened to things.
Iron rusts from disuse; water loses its purity from stagnation... even so does inaction sap the vigor of the mind.
Nothing strengthens authority so much as silence.
He who is fixed to a star does not change his mind.