Jason Clarke Antiques has dated this piece to the 1800s.

One of the largest of its type that I have handled measuring ten inches in diameter, this example retains most of its original lacquer to the brasswork and although it does have some scratches to the ten o clock position of the lens it does not effect its function.
A very imposing magnifier which would have been used in either a library or gallery setting to allow closer visual inspection.
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