Archimedes Screw

Archimedes' Screw, a mechanical contrivance for elevating water, named after its inventor. In its simplest form, this is a hollow end in water. When rotated about its axis, water enters at this end, and is lifted up by the screw spiral placed in an oblique position with its lower end in water. When rotated about its axis, water enters at this end, and is lifted up by the screw action. If the rotation were reversed, the water would be lowered again.