A mechanical device for lifting
water (aka a "
pump"). Its invention is attributed to
Archimedes of
Syracuse.
The
Archimedean Screw is essentially a
screw inside a tube, with a
handle attatched to the screw.
As the handle is turned, water at the bottom end of the tube is scooped up by the bottom end of the screw. Since the screw is shaped so that the water cannot run down and out the bottom, the water eventually reaches the top of the tube and flows out.