Item is a novelty compact collapsible tinplate stereoscope given as a premium from cigarette brands. The cover of the object is built in the shape of a small book. It is detailed with green, gold and yellow floral designs. Once item is unlocked, a viewer with small lenses pops out parallel to a small folding card holder. The lenses slide in and out horizontally and the built in round topped frame move back and forth. Object was built like this to allow the user to focus. Stereoviews are 40 mm. Viewing lenses are 60 mm in focal length. This object was used to view two nearly identical photographs, or stereographs, as one three dimensional image. The stereograph would be placed in the card holder and adjusted to fit the user's vision until the two images overlap to mimic a three-dimensional effect.This stereoscope comes with 12 black and white silver gelatin stereographs of Victorian Celebrities.
Written on object : The Pocket Rotoscope The Rotary Photographic Co. Lo. 12 New Union St. London, E.C. Works, West Drayton, Midd With 12 Real Photographic Stereograms Views, Staturary, Celebrities, Children, Comic Scenes, Etc. Patented Ro. No. 442.342.