A Pascall’s apparatus. Brass pilar with graduated measuring bar and weight supporting the limb with cone shaped glass vessel, raised from the iron base with brass tumbler. Complete with two different shaped glass vessels mounted in brass colors to fit the limb.
To show that the pressure on the bottom of a vessel depends only on the area of the base and the height of the column of water supported by it, and not on the shape of the vessel.
France, ca. 1870.