Gravesande's ring and ball with chain — a device for showing thermal expansion. A captive brass ball is secured to a mounted brass ring by a chain, and the ring is mounted on a bar with a wooden handle. The ball passes through the ring when cool but will not pass through after being heated.

We are manufacturers and suppliers of the Ball and Ring Apparatus (Gravesande), serving Algeria, Argentina, Australia, Bahrain, Bangladesh, Belgium, Bhutan, Brazil, Cambodia, Cuba, Cyprus, Denmark, Ecuador, Egypt, Ethiopia, Finland, France, Georgia, Germany, Ghana, Hungary, Iceland, Italy, Japan, Jordan, Kenya, Kuwait, Malaysia, the Philippines, Tanzania and Uganda.