French Table Stereo Viewer By Unis, Paris

French, c.1900, brass label to the front reads 'UNIS FRANCE, STEREOSCOPES MATTEY PARIS' the viewer with door to base with 2 drawers each containing 4 original cassettes each to hold 24 13.8cm x 5.9cm glass slides, with working internal mechanism, focusing eyepieces with interocular adjustment, finished in French polished wooden case, height 50cm, with 3 extra cassettes of slide and other in card cases, most of travels around Europe