What water-lifting machine did Leonardo da Vinci study using a rotating helical screw?

Leonardo da Vinci studied Archimedes’ screw as a water-lifting machine using a rotating helical screw.

An Archimedes’ screw consists of a helical surface inside a tube or around a central shaft. As the screw rotates, water is carried upward from a lower level to a higher one. Leonardo examined screw mechanisms in his notebooks as part of his wider interest in hydraulics and useful machines.

The invention is traditionally associated with Archimedes of Syracuse, who lived in the 3rd century BCE. Leonardo therefore did not originate the machine, but his studies helped document and analyze ancient mechanical principles during the Renaissance.

This device is different from Leonardo’s flying-machine designs and from the helical rotor often linked with vertical-flight sketches. In the water-lifting machine, the screw’s job is to transport liquid upward, not to generate lift in air.