Photo: Model of a robot based on the drawings by Leonardo da Vinci; photo by Erik Möller, Genie exhibit, Berlin 2005.
Leonardo da Vinci was respected as an engineer, during his lifetime. When he fled to Venice in 1499 he was employed as an engineer and devised a system of moveable barricades to protect Venice city from attacks. He kept detailed notes and sketches of his scientific ideas. His journals include a vast number of notes on inventions, some of which are practical and others found to be impractical. He did not take much pain to conduct experiments or prove scientifically about scientific ideas he noted in his journals. They include musical instruments, hydraulic pumps, crank mechanisms, mortar shells, bridges, flying machines (a helicopter and a light hang glider), mills, levers, hoists, winches, pulleys, gears, lens-grinding machine, hydraulics, war machines, cannons, diving suit, and many more.