What water-lifting machine did Leonardo da Vinci design as a continuous screw conveyor?

Leonardo da Vinci designed and studied an Archimedes’ screw as a continuous water-lifting machine.

The device consists of a helical blade inside a tube or cylindrical housing. As the screw turns, water is carried upward along the spiral and discharged at a higher level. Leonardo’s drawings show his interest in using the mechanism for drainage, irrigation, and moving water.

The basic principle was much older than Leonardo. It is traditionally associated with Archimedes, the Greek mathematician and engineer, and may have earlier roots in water-raising technology. Leonardo did not invent the ancient screw, but he examined its form and possible engineering applications.

A common mistake is to call every spiral water device a modern water turbine. A turbine extracts energy from flowing water to produce rotation; an Archimedes’ screw uses rotation to transport water upward. That difference explains why the machine is classed as a pump or conveyor.