The apparatus used in the experiment consists of a metal ball suspended by a metal chain and a ring connected to the stand. The inner diameter of the ring is the same as the outer diameter of the ball, so that ball can easily pass through the ring.

If we heated the ball on a Bunsen flame for two minutes and try to pass the ball through the ring, we can see that ball does not pass through the ring.
Conclusion:-
1.The ball is not able to pass through the ring because it got expanded on heating.
2.Gravesande’s ring and ball experiment conclude that solids will expand on heating.