Info Thermal Expansion (Ball and Ring) Type of activity: demo Activity code: 00000 Courses PHY205 Description: Set up the propane torch and secure with a clamp & retort stand as shown in the photo. Open the gas valve Light the torch with the flint lighter and adjust the flame size. Heat up the ball so that it no longer goes through the ring. Apparatus Torch Gravesande's Thermal Expansion Ball and Ring Lighter (Flint) Clamp (Flask) Retort Stand Clamp (Bosshead)