For demonstrating tht pressure in a liquid is a function of depth only, and not the shape of the vessel. Consists of a special from tripod base carring two rods, to one of which is attached a metal reservoir, adjustable to height by means of a friction clamp. The other rod supports the vase holder and indicator pointer, both adjustable to height. The vase holder is equipped with a corrugated metal diaphragm, the motion of which transmits the liquid pressure applied through a multiplying arrangement to an indicating dial. The three glass vases, all 50 cm high bu of different shapes, are cemented to brass collars which are readily interchangeable in the threaded vase holder.