This is a classic late 19th-century Holmes-style stereoscope frame, a popular Victorian-era device used to view "stereographs" (dual-image cards) in 3D. Based on the stamping, this model features the April 5, 1881, patent improvements, which typically involved the sliding wood carrier and the folding handle. Constructed from an engraved aluminum or tin-plate hood with a velvet-lined edge and a mahogany-toned wood track, it represents the primary way people experienced "virtual travel" before the advent of cinema. The item is in fair to good vintage condition. The metal hood retains its decorative engraving with minimal surface wear. The original velvet light-seal around the hood is a bit worn and frayed. PLEASE NOTE: It does not have the lenses anymore, its' simply the handheld frame. The wooden track and turned-wood handle appear structurally sound. Dimensions: 33cm (l)