For many years, folio 812r of the Codex Atlanticus was considered as Leonardo’s famous “automobile” project. Only recently has it revealed its true nature as a cart devised for use in theatrical settings.
The manuscript page shows two distinct projects, a provisional and preparatory drawing, and a more well-defined one at the centre of the folio. Two large spiral springs underneath the horizontal cogwheels of the cart provide the motive power and set the wheels in motion; they also act as a lever system for theatre puppets. An additional ingenious device serves as a remote control handbrake.