What type of machine did Leonardo da Vinci design with two spiral screws to lift water?

Leonardo da Vinci designed a water-lifting machine based on Archimedes’ screw.

An Archimedes’ screw is a rotating helical surface inside a tube or trough. As it turns, pockets of water move upward along the spiral, allowing water to be raised from a lower level to a higher one. Leonardo studied screw-based water machines and drew versions with multiple spiral elements.

The device was not Leonardo’s invention. It is traditionally associated with Archimedes of Syracuse, who lived in the third century BCE, although the precise historical origin of the mechanism is debated. Leonardo’s work belongs to the later history of analyzing and adapting established machines.

This water screw is different from a water wheel. A water wheel is turned by flowing water and can provide power, whereas a screw pump uses rotation to move water. Leonardo explored both water movement and mechanical power in separate studies.