"The Lady with an Ermine" - National Museum, Kraków
"Virgin of the Rocks" (det.) - Musée du Louvre Paris
c.1495-97. Codice di Madrid I, f. 145 r. Madrid, Biblioteca Nacional
Leonardo argued against the existence of a perpetual motion machine, and in his demonstration of its impossibility he exploits laws of friction, balance and levers. Each rod ends with a weight, and the weights, once moved, are the cause of the machine's motion. Let us try to apply some strength, by turning the wooden wheel. We will observe that when the rods return to the starting balance position, the machine will stop moving if motion is not provoked once again.
Design for a helicopter
Studies of the Arm