Unknown, 1750 c.
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photo - whole telescope
Basic Info

Maker: Unknown

Year: 1750 c.

Year Range: -

Year Notes:

Manufacturing Location: England


Signature Notes:


No stand present.

Collection: National Maritime Museum

Accession #: NAV1513


Royal Museums Greenwich. "Hand-held telescope". http://collections.rmg.co.uk/collections/objects/43725.html [Accessed: June 2016].

Public Notes:

"This non-achromatic terrestrial telescope has a green rayskin (shagreen) barrel and four draw tubes made of green vellum with brass fittings. Black dotted lines around the draw tubes indicate the telescope's optimum working length. Both the eyepiece and objective lenses have sliding covers for protection. The telescope is typical in style of a telescope made in England in this period. It was probably intended for terrestrial rather than astronomical use and incorporates lenses that correct the inverted image produced by the objective lens" (Royal Museums Greenwich).

Length (open): 988

Length (closed): 314


Exit pupil:

Object status:

Optical Basics

Objective type: unconfirmed

Optical style terrestrial

Physical style

Functional style

Materials: brass, shagreen, vellum, glass

Optical/Lab Data

Drawtube data:

Drawtube notes:

Diameter: 50 mm

Objective Data



652 ± ± 0.3 ± 0.3 ±
575 ± ± 0.0 ±
482 ± ± 0.2 ± 0.6 ±