Archimedes' screw solved one of the greatest practical problems of antiquity, which was to find an easy way to lift liquids. Archimedes created a machine that allowed this operation to be carried out with relative simplicity: the Archimedes' screw. The machine consists of a large screw placed inside a tube, not necessarily welded and watertight. The lower part of the tube is immersed in a liquid and, by turning the screw, each step collects a certain amount of substance that rises along the spiral until it comes out through the upper part, to be discharged into a storage basin. The energy for rotation can be provided by a handle, by animals, by windmill propellers or by agricultural tractors.