Gráficoscopio or photo viewer with slide viewer, Materials: wood, glass, bakelite, brass. In excellent condition. This is an optical instrument for two-dimensional images and give an illusion of depth and relief. It consists of a wooden box with a flip top panel and a circular lens attached to the front panel. Inside there postal view, which can be rotated by a rack, two side actuating controls, one right and one on the left. It holds 50 cards, currently there are 47 in the interior. You can also adjust the focus by specific knobs, left and right. At the bottom front of the instrument is a brass plate with the inscription"" Felix Pneuma"" (see photo). Operation: Stereoscopic images can be viewed by turning the side button. Fine mahogany wood. Dimensions: Height 50cm, Width 25cm, Depth 28cm