Jason Clarke Antiques has dated this piece to the 1800s.
It is fixed with a second brass collar which holds a simply turned mahogany top providing a flat surface for the placement of electrostatic machine accessories.

Given the early nature of this example, it would have been manufactured to accompany either a Ramsden or Nairne type electrostatic machine and would have been used to insulate its subject matter from a path to ground.

Sadly, the piece is unnamed so little can be divulged about the maker but nevertheless a super example and a piece of apparatus which is seldom encountered. The glass and the associated woodwork remain in very good condition.
Circa 1810.
Jason Clarke Antiques has dated this piece to the 1800s.
You can view the stock and full dealer information on the Jason Clarke Antiques Profile Page