The stereographoscope is a combined graphoscope and stereoscope. This one is a French model, most likely manufactured by A. Mattey from Paris.
The stereographoscope was a British invention. The first design was patented on 1 February 1864 by Charles John Rowsell[1]. It was a large viewer consisting of a large magnifying glass for viewing normal photographs, combined with two stereo lenses for viewing paper card stereoviews. The addition of stereo lenses most likely had to do with the enormous popularity of stereo photography in the 1850s and 1860s.

This viewer is a more compact French design that is fully collapsible. A logo with a sun symbol is carved into the wood, but the name of the manufacturer is missing. Several identical models are seen with a star logo, one of Mattey’s brands.
The stereographoscope can be focused by sliding the holder in which the photograph or paper card stereoview is placed forwards or backwards, similar to the Holmes-Bates stereoscope. The distance between the lenses cannot be adjusted. The wood is finished in Napoleon III style with a black color and decorations. It looks very attractive. The viewer’s stereo lenses can only be used for viewing paper stereocards but the viewing experience is rather disappointing. However, the large magnifying glass is useful for viewing vintage photos.
The French stereographoscopes are cheaply manufactured and not rare. They often appear at online auction sites, usually for a price that is much too high.
References
- Wing, Paul. Stereoscopes: the first one hundred years, 1996. p.131