The Expansion of Liquids Apparatus is a laboratory instrument used to measure the thermal expansion of liquids. It typically consists of a glass tube with a bulb at one end and a graduated scale on the other. The liquid sample is filled into the bulb and the apparatus is heated or cooled, causing the liquid to expand or contract.

As the volume of the liquid changes, the level of the liquid in the graduated scale also changes, allowing for the measurement of the volume of the liquid at different temperatures.

The data obtained from the Expansion of the Liquids Apparatus can be used to calculate the coefficient of thermal expansion of the liquid. This apparatus is useful for studying the thermal properties of liquids and can be used in various scientific disciplines such as chemistry, physics, and materials science.