Ball & Ring

Consisting of a joint less copper calorimeter 75 x 50 mm on rubber supports, spun outer copper vessel of 100 x 75 mm diameter copper lid for outer vessel with central tubule for thermometer and slit for copper stirrer, with a looped copper stirrer for the inner vessel.

Gravesende’s ring mounted on tripod stand, ball with chain. Cold ball passes through the ring but does not pass when heated.