De Kievit, Menaldum of the "upright shaft" there are two "crown wheels" The upper "crown wheel", which has 35 cogs drives an Archimedes' screw via a "crown wheel". This screw was used to pump water into the polder. The lower "crown wheel", which has 35 cogs, drives a gearwheel with 32 cogs on the axle of an Archimedes' screw, which was used to drain the polder. The axle of the screw is diameter and long. The screw is diameter. It is inclined at 10°. Each revolution of the screw lifts of water. "De Kievit" is open to the public at any time it
Archimedes number Archimedes number In viscous fluid dynamics, the Archimedes number (Ar) (not to be confused with Archimedes' constant, π), named after the ancient Greek scientist Archimedes is used to determine the motion of fluids due to density differences. It is a dimensionless number defined as the ratio of external forces to internal viscous forces and has the form: where: When analyzing potentially mixed heat convection of a liquid, the Archimedes number parametrizes the relative strength of free and forced convection. When Ar » 1 natural convection dominates, i.e. less dense bodies rise and denser bodies sink, and when Ar « 1