Can't identify?

I was wondering if someone would be able to help me identify this item and possibly give me an appraisal. The large ball in the center is brass as well as the 2 smaller balls on the sides. The "arms" rotate and when spinning fast enough they raise. The center ball then will raise also with speed. There is a gear that is not shown on the bottom of the item as it is on a wooden stand. Any information would be greatly appreciated. Thanks!