Comprising two iron casted stand of 180mm height joined by two chrome plated rods, with an expansion rod, length 380mm, fixed on one stand and resting on a Friction Pointer placed at the other. With graduated scale 0-90° with 3 expansion bars of Iron, Aluminium and Brass.

For demonstrating the differential expansion of two different metals. One each brass and iron plates 350 x 35mm l/ength x breadth riveted together from end to end with wooden handle.