It is a shallow [semi flat] dish [?], which is mother-of pearl. It is mounted on a silver bamboo designed tripod, and attached with a silver butterfly that basically screws onto the tripod.
I will attempt to post photo. I know that Willaim fowle was known for approx. three years work under his Uncle Thomas Fowle. I also know, via the victoria and Albert Museaum that during that period WF was known for dressing table sets and the silversmiths of that time were into chinese design [as they thought it would be].