Artist and multifaceted genius, unsurpassed in any century, painter, scientist, but most of all military engineer and manufacturer, universal talent of the Renaissance, linked to the experimental method as the only source of any theory of construction, Leonardo da Vinci (1452-1519) left us numerous projects of self-propelled vehicles, complete with drawings and sketches of the details. One of the most interesting is the spring carriage, whose sketch can be found in the Codex Atlanticus (Sheet 296). In this sketch, we clearly see the first example of an independent transmission and of handlebar steering; and probably of a device for reverse gear.