Unknown, 1740 c.
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photo - whole telescope
Basic Info

Maker: Unknown

Year: 1740 c.

Year Range: -

Year Notes:

Manufacturing Location:


Signature Notes:


No stand present.

Collection: National Maritime Museum

Accession #: NAV1558


Royal Museums Greenwich. "Portable telescope". http://collections.rmg.co.uk/collections/objects/43770.html [Accessed: June 2016].

Public Notes:

"This barrel and three draw tubes of this telescope are covered in vellum and the barrel is decorated with gold tooling. Stop lines on the draw tubes indicate the optimum working length of the telescope. The lenses are set in horn mounts, although the objective lens (which would have been non-acrhomatic) is now missing. There is a sliding eyepiece cover made of brass" (Royal Museums Greenwich).

Length (open): 846

Length (closed): 306


Exit pupil:

Object status:

Optical Basics

Objective type: N/A

Optical style

Physical style

Functional style

Materials: vellum, horn, brass, glass, gold tooling

Optical/Lab Data

Drawtube data:

Drawtube notes:

Diameter: 51 mm

Objective Data



652 ± -0.2 ± 0.5 ± ±
575 ± 0 ± ±
482 ± 1.3 ± 0.5 ± ±