Leonardo da Vinci considered the idea of a self-propelled vehicle in the 15th century. In 1760 a Swiss clergyman, J.H. Genevois, suggested mounting small windmills on a cartlike vehicle, their power to be used to wind springs that would move the road wheel. Genevois’s idea probably derived from a windmill cart of about 1714. Two-masted wind carriages were running in the Netherlands in 1600, and a speed of 20 miles (30 km) per hour with a load of 28 passengers was claimed for at least one of them. The first recorded suggestion of wind use was probably Robert Valturio’s unrealized plan (1472) for a cart powered by windmills geared to the wheels.