What hydraulic device did Leonardo da Vinci study for raising water using a rotating screw?

Leonardo da Vinci studied Archimedes' screw for raising water using a rotating screw.

An Archimedes' screw consists of a helical surface wrapped around a central shaft inside a tube or trough. When the screw turns, pockets of water move upward along the spiral. Leonardo examined versions of this ancient hydraulic machine in his studies of canals, irrigation, drainage, and water-powered engineering.

The device was not invented by Leonardo. It is traditionally associated with Archimedes, who is said to have developed it in the third century BCE, although the exact history is debated and earlier water-raising devices may have existed. Leonardo's contribution was to analyze and adapt mechanical principles rather than claim authorship of the ancient machine.

This distinction matters because Leonardo's notebooks contain both original inventions and careful studies of earlier technologies. His drawings often improved understanding through detailed geometry and mechanism diagrams. The screw remained useful because it could lift water continuously with relatively simple construction.