Demainbray's hydrostatic paradox vessels
Vessels for demonstration of the hydrostatic paradox, maker unknown, before 1753. Once belonged to Stephen Demainbray.
Vessels for demonstration of the hydrostatic paradox, before 1753. The vessels were filled with water. A balance beam was suspended above the apparatus with one arm carrying a piston which could move vertically in the container, and the other carrying a counter-balance weight in a scale-pan. The pressure on the piston in all three vessels was found to be the same, since pressure is dependent on depth and not on the volume of water present. These vessels once belonged to Stephen Demainbray and was used by him in his lectures on natural philosophy. Demainbray worked as superintendent at the King's observatory at Kew from 1768 and his collection of instruments and apparatus was absorbed into the King's own collection.