What water-lifting machine did Leonardo da Vinci sketch as a helical screw?

Leonardo da Vinci’s helical water-lifting concept is an Archimedes’ screw.

An Archimedes’ screw consists of a helical surface inside a tube or around a shaft. As the screw rotates, water is carried upward along the spiral. Leonardo studied and drew versions of this ancient device, applying Renaissance engineering observation to a mechanism already associated with Archimedes of Syracuse.

The machine could be used for irrigation, drainage, or raising water to a higher level. Leonardo’s interest in screw mechanisms also connected with his studies of air, water, motion, and machines. His drawings should not be treated as proof that he invented the principle.

The key distinction is historical: Leonardo redesigned and documented an established type of water pump, whereas his aerial screw was a separate flying-machine concept inspired by rotary motion. Both use a helical form, but they serve different purposes.