Leonardo's self-propelled cart

Leonardo had been well aware that the powering force provided by the springs drops significantly when they unwind.

In order to deliver smooth and stable motion, the machine features a balance wheel, as used in clocks.

The control mechanism is quite complex and allows it to follow a pre-programmed path automatically.

The machine also features a mechanism similar to a differential that in addition allows the turning angle to be set.

A replica of the self-propelled cart is kept at the museum Clos Lucé, near Château d'Amboise, in France.