What water-lifting machine did Leonardo da Vinci describe using a continuous helical screw?

Leonardo da Vinci described an Archimedes’ screw as a water-lifting machine using a continuous helical screw.

The device consists of a spiral surface inside a cylinder or wrapped around a central shaft. When the screw turns, water is carried upward along the spiral. Leonardo studied and drew screw-based machines as part of his extensive work on hydraulics, canals, drainage, and construction.

The machine was not Leonardo’s invention. It is traditionally associated with Archimedes of Syracuse, who lived in the third century BCE. Leonardo’s importance here is his detailed Renaissance analysis and adaptation of established mechanical principles for new engineering applications.

Archimedes’ screws remain useful for moving water, sewage, grain, and other materials. Their operation differs from a pump that uses pistons or impellers: the rotating helix physically transports material along its length. This is why the device can lift water steadily even with a relatively simple mechanism.