Ball and Ring Apparatus

Demonstrate the thermal-expansion of metal with this simple but visually impressive apparatus. — The brass ball will pass through the ring when both are at the same temperature (i.e. when both are hot or cold). — However, if you heat the ball but not the ring, the ball will not pass through!

One of our own suggested experiments – heating the ring while putting the ball in ice water – you’ll see what happens!

Both the ball and ring are mounted on black lacquered wooden handles and are each approximately 10″ (25.5cm) in length.