For demonstrating the different thermal expansions of various liquids. Comprising five bulb tubes with plastic scales, mounted in a frame and supported in a water trough 240 x 108 x 77 mm deep. The frame has clamps to secure it to the trough and two cross members, the lower cross member having holes, and the upper tubules to locate the bulb tubes. Dimensions overall 240 x 115 x 460 mm high approx. Bulb diameter 35 mm. Bulb stem 400 mm. Supplied complete with glass bulbs and scale.