What kind of spiral water pump did Leonardo da Vinci illustrate in his engineering studies?

Leonardo da Vinci illustrated an Archimedes’ screw in his engineering studies.

An Archimedes’ screw is a helical surface wrapped around a central shaft inside a tube or trough. When the shaft turns, water is carried upward along the spiral. Leonardo drew versions of this ancient lifting device while investigating hydraulics and machines.

The mechanism is named for Archimedes, who is traditionally associated with its use in ancient Greece, although the exact origins of the device are debated. Leonardo therefore studied and adapted an established principle rather than inventing the screw himself.

The screw is still used for drainage, irrigation, wastewater movement, and fish passage. It is also different from Leonardo’s canal gates: a screw lifts water mechanically, while a lock gate controls the movement of boats between levels.