Comprising six equal rods of copper, iron, lead, brass, Zinc and aluminium, each 130 x 3mm diameter, mounted in corks with their lower ends in a tank 210 x 75 x 75mm. The tank is supported on four legs at a height of approximately 170mm above the bench. In use, the rods are lightly coated with paraffin wax and the rates of melting are compared.