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
Tochmaland, Kollum containing an electrically driven Archimedes' screw was erected next to the mill. A proposal to demolish the mill was rejected by the mayor of the gemeente Kollumerland en Nieuwkruisland. 0n 30 December 1948, the mill was purchased by the gemeente. Restorations were undertaken in 1949, 1963 and 1983. since 1995, an electric motor has been installed in "Tochmaland" to drive its Archimedes' screw, and the installation in the brick shed demolished. "Tochmaland" is what the Dutch describe as an "Grondzeiler". It is a two-storey smock mill on a single-storey base. There is no stage, the sails reaching down almost to