Screw turbine connected to a generator through a gearbox. The Archimedean screw is an ancient invention, attributed to Archimedes of Syracuse (287–212 BC.), and commonly used to raise water from a watercourse for irrigation purposes. In 1819 the French engineer Claude Louis Marie Henri Navier (1785–1836) suggested using the Archimedean screw as a type of water wheel. In 1916 William Moerscher applied for a U.S. patent on the hydrodynamic screw turbine. The Archimedean screw turbine is applied on rivers with a relatively low head (from 1 m to 10 m) and on low flows (0.01 m³/s up to around 10 m³/s on
Trammel of Archimedes Trammel of Archimedes A trammel of Archimedes is a mechanism that generates the shape of an ellipse. It consists of two shuttles which are confined ("") to perpendicular channels or rails and a rod which is attached to the shuttles by pivots at fixed positions along the rod. As the shuttles move back and forth, each along its channel, the end of the rod moves in an elliptical path. The semi-axes "a" and "b" of the ellipse have lengths equal to the distances from the end of the rod to each of the two pivots. An ellipsograph is a trammel