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
Archimedes (crater) near the rim. Scattered wisps of bright ray material lie across the floor, most likely deposited by the impact that created Autolycus. To the south of Archimedes extends the Montes Archimedes, a mountainous region. On the southeastern rim is the Palus Putredinis, a lava-flooded plain containing a system of rilles named the Rimae Archimedes, which extends over 150 kilometers. North-northwest of Archimedes stand the Montes Spitzbergen, a string of peaks in the Mare Imbrium. East of Archimedes is the crater Autolycus. Northeast of Archimedes is the prominent crater Aristillus. The lava plain between Archimedes, Aristillus, and Autolycus forms the Sinus