In his notes, Leonardo remarks that, with a linen curtain shaped into
a pyramid having a base 12 yards (about 7 metres) across and equally
deep, if it is stiffly held open, "ognuno si potrÓ gettare da qualsiasi
altezza senza alcun rischio" (anyone can jump from no matter what height
without any risk whatsoever).
Codex Atlanticus, sheet 1058