Archimedes' screw a crank mechanism in his "Bellifortis" (1405). This mechanism quickly replaced the ancient practice of working the pipe by treading. The Archimedes screw consists of a screw (a helical surface surrounding a central cylindrical shaft) inside a hollow pipe. The screw is usually turned by windmill, manual labor, cattle, or by modern means, such as a motor. As the shaft turns the bottom end scoops up a volume of water. This water is then pushed up the tube by the rotating helicoid until it pours out from the top of the tube. The contact surface between the screw and the
Trammel of Archimedes in the form of the standard parametric equations for an ellipse in canonical position. The further equation is immediate as well. The trammel of Archimedes is an example of a four-bar linkage with two sliders and two pivots, and is special case of the more general oblique trammel. The axes constraining the pivots do not have to be perpendicular and the points "A", "B" and "C" can form a triangle. The resulting locus of "C" is still an ellipse. Trammel of Archimedes A trammel of Archimedes is a mechanism that generates the shape of an ellipse. It consists of two