F4509

Portable telescope Long Caption: The barrel of this non-achromatic telescope is covered in rayskin (shagreen) that has been dyed green, while the three draw tubes are made of white vellum. Stop lines marked with dots on the draw tubes indicate an optimum working length of the telescope of over 1000 mm. The brass fittings include sliding eyepiece and objective lens covers. Credit line: © National Maritime Museum, Greenwich, London Object: NAV1519 Artist: unknown Date: circa 1760 Medium: rayskin (shagreen); vellum; brass; wood; glass Size: length: 352 mm (closed), 1010 mm (open to stop lines, mamm x.); diameter: 48 mm (barrel) Click here to buy a bespoke print of this image.