I put my loose stone in it and hang the ball on a hook then lower it into a water-filled container up to a mark on the chain on the mesh tea ball. The tea ball and chain and the water-filled container sit on an electronic scale. I have already determined the weight of the empty tea ball on its chain in the water and the carat weight of the stone. With the stone in the tea ball in the water in record that weight. In our Reference Library, and in several other sources, there are very good articles which walk you through the process of weighing the stone and doing the arithmetic to determine the specific gravity of the stone. (By the way, some writers refer to the process as mathematics. Don't let that put you off your stride. It's really just arithmetic!)
I have been really sick, and have been mostly in bed, so I haven't been able to keep on top of my Mesh Tea Ball Forum topic, and I do apologize to everyone. I'll also try to get a drawing of my rig uploaded to my Mesh Tea Ball Forum topic. So--Stay tuned to the Mesh Tea Ball Forum topic.