The Linear Expansion Apparatus is an instrument that permits steam to be passed through tubes of different metals to measure and compare expansions. The change in dimension is measured by a precision 'Dial Indicator', as used in engineering, to measure to 0.01mm increments. The kit is complete with a thermometer to monitor the temperature of the metal tube both cold and hot. Steam can be generated from a boiling flask with a side branch to carry off the steam.