late 19th century, adjustable concave eyepiece and convex objective lens in lacquered brass mounts, on printed representation of the lenses and light rays to demonstrate the production of the erect virtual image, mounted on stand in stained and ebonised beech, stand stamped with P G S trademark, height 24cm
late 19th century, adjustable concave eyepiece and convex objective lens in lacquered brass mounts, on printed representation of the lenses and light rays to demonstrate the production of the erect virtual image, mounted on stand in stained and ebonised beech, stand stamped with P G S trademark, height 24cm
Auction: The Collectors Sale, 9th Aug, 2022