Archimedes' screw screws of decreasing pitch are used for the compaction of waste material. If water is fed into the top of an Archimedes screw, it will force the screw to rotate. The rotating shaft can then be used to drive an electric generator. Such an installation has the same benefits as using the screw for pumping: the ability to handle very dirty water and widely varying rates of flow at high efficiency. Settle Hydro and Torrs Hydro are two reverse screw micro hydro schemes operating in England. The screw works well as a generator at low heads, commonly found in English
Archimedes and the Cylinder I, II", "On Spirals", "On Conoids and Spheroids", "On Floating Bodies I, II", "On the Measurement of a Circle", "The Sand Reckoner". c. Boyer, Carl Benjamin "A History of Mathematics" (1991) "Arabic scholars inform us that the familiar area formula for a triangle in terms of its three sides, usually known as Heron's formula — "k" = , where "s" is the semiperimeter — was known to Archimedes several centuries before Heron lived. Arabic scholars also attribute to Archimedes the 'theorem on the broken chord' ... Archimedes is reported by the Arabs to have given several proofs