Archimedes screw

Archimedes' screw is a tube bent around a rod into the shape of a spiral. It has been used since ancient times to lift water a distance of a few feet from a pool or stream. (May be, it looked like this one? ) The device, often used to direct water into an irrigation channel, was composed of a wooden beam, several feet long, around which a spiral screw thread was built of layers of flexible, pitch-covered wood strips. Over this thread were fastened tight-fitting narrow planks running the length of the beam and giving it the appearance of a tube. Vitruvius (1st century BC) described it as a "natural imitation of a spiral shell."

To operate the screw, it is angled into the water so that the underportions of the threads at the submerged end can cup and hold the water. When the screw is rotated on its axis in the proper direction, the cupped water is lifted up along the underside of the beam on the moving threads until it reaches and can flow out of the tube's raised end.

In Roman times the Archimedes' screw was operated by walking on it, as lumberjacks today walk on and spin a floating log. When it came into general use in the 15th century, it was rotated by turning a crank.