De Westermolen, Kollumerpomp of the upright shaft. At the bottom of the upright shaft is the "crown wheel", which has 41 cogs, drives a gearwheel with 42 cogs on the axle of the Archimedes' screw. The axle of the Archimedes' screw is diameter. The screw is diameter . It is inclined at 16.7°. Each revolution of the screw lifts of water. The Archimedes' screw that pumped water into the polder has been removed. "De Westermolen" is open on Friday mornings. It is also open on Saturday mornings if there is enough wind to work the mill. De Westermolen, Kollumerpomp De Westermolen is a
SS Archimedes overhaul. Her engines and machinery were removed on an unspecified date at Sunderland, after which she continued in service as a sailing ship. In 1852, her sails and rigging were renewed, but she disappeared from the Register again a year or two later. She reportedly ended her career in the 1850s, in service between Chile and Australia. Although the adoption of the screw propeller was an historical inevitability given the work of John Ericsson and others, "Archimedes" considerably hastened acceptance of the technology. The Dover trials, carried out in April–May 1840, persuaded the Royal Navy to build a 900-ton steam