Jason Clarke Antiques has dated this piece to the 1900s.
The central strut carries a candle holder and has a brass support to the back which carries two plane mirrors which can be adjusted to varying degrees around the scale.

A simple yet effective demonstration piece for showing the Law of Reflection on surfaces.
With its black painted finish, the apparatus is likely to have been manufactured by the company of Max Kohl. Their catalogues of the Edwardian period provide similar examples but this is sadly unmarked so not directly attributable, the only mark present on this piece is the serial number of 9350.
Nevertheless, a large, complete and fine example of its type.
Circa 1900
Jason Clarke Antiques has dated this piece to the 1900s.
You can view the stock and full dealer information on the Jason Clarke Antiques Profile Page