De Marssumermolen, Marssum 57 cogs. This drives the "wallower" (31 cogs) at the top of the "upright shaft". At the bottom of the "upright shaft" there are two "crown wheels"' The upper "crown wheel", which has 17 cogs drives an Archimedes' screw. The axle of the Archimedes' screw is diameter and long. This screw is used to pump water into the polder. The lower "crown wheel", which has 43 cogs, drives a gearwheel with 38 cogs on the axle of an Archimedes' screw, which is used to drain the polder. The axle of the screw is diameter and long. The screw is diameter.
Trammel of Archimedes Trammel of Archimedes A trammel of Archimedes is a mechanism that generates the shape of an ellipse. It consists of two shuttles which are confined ("") to perpendicular channels or rails and a rod which is attached to the shuttles by pivots at fixed positions along the rod. As the shuttles move back and forth, each along its channel, the end of the rod moves in an elliptical path. The semi-axes "a" and "b" of the ellipse have lengths equal to the distances from the end of the rod to each of the two pivots. An ellipsograph is a trammel