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
Archimedes (CAD) Archimedes (CAD) Archimedes – "The Open CAD" – (also called Arquimedes) is a computer-aided design (CAD) program being developed with direct input from architects and architecture firms. With this design philosophy, the developers hope to create software better suited for architecture than the currently widely used AutoCAD, and other available CAD software. The program is free software released under the Eclipse Public License. Archimedes uses its own XML-based open format, which resembles SVG. It does not yet include support for other , but DXF support is planned. Archimedes is written in Java, and the latest version runs on Windows, Mac