Unknown, 1740 c.
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photo - whole telescope
Basic Info

Maker: Unknown

Year: 1740 c.

Year Range: -

Year Notes:

Manufacturing Location: France


Signature Notes:


No stand present.

Collection: National Maritime Museum

Accession #: NAV1498


Royal Museums Greenwich. "Hand-held telescope". http://collections.rmg.co.uk/collections/objects/43710.html [Accessed: June 2016].

Public Notes:

"The barrel of this non-achromatic telescope is covered in red leather that is decorated with gold-tooled motifs. There are five draw tubes covered in marbled paper. The other fittings are of turned wood and bone. The objective lens and some of the fittings are now missing. This telescope is assumed to have been made in France because of an inscription on one of the draw tubes in French. Telescopes in this period had to be long, since lenses with long focal lengths were used in order to minimise chromatic aberration - the appearance of coloured fringes around the object being viewed. The stop lines drawn onto the draw tubes of this telescope indicate a maximum optimum working length of over 1600 mm" (Royal Museums Greenwich).

Length (open): 1645

Length (closed): 470


Exit pupil:

Object status:

Optical Basics

Objective type: N/A

Optical style

Physical style

Functional style

Materials: leather, bone, wood, paper

Optical/Lab Data

Drawtube data:

Drawtube notes:

Diameter: 60 mm

Objective Data



652 ± 1.0 ± 0.2 ± ±
575 ± 0 ± ±
482 ± -1.6 ± 0.2 ± ±