This apparatus (incomplete) is known as 's Gravesande column, named after its inventor. The "column" is an all-purpose stand suitable for a wide range of mechanical and hydrostatic experiments.
The square base supports a vertical column holding four crossbars, of which four rotate and one slides. A tackle and a polyspaston are suspended from two different crossbars. The tackle consists of two ebony blocks each carrying five ivory sheaves and interconnected by a single cord. With this combination, an effort applied to the free end of the cord can lift a load ten times greater. The polyspaston comprises two horizontal rods each carrying three pulleys connected by a cord. This combination makes it possible to lift a weight six times as great as the effort applied. Provenance: Lorraine collections.