Unknown, 1710 c.
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photo - whole telescope
Basic Info

Maker: Unknown

Year: 1710 c.

Year Range: 1675-1750

Year Notes:

Manufacturing Location: France


Signature Notes:


gold-tooled "L" under a crown on the caps and on main tube

No stand present.

Collection: National Maritime Museum

Accession #: NAV1592


Royal Museums Greenwich. "Non-achromatic telescope". http://collections.rmg.co.uk/collections/objects/43804.html. [Accessed: June 2016].

Public Notes:

Museum Description:
"This non-achromatic telescope has six green vellum draw tubes, allowing it to be extended to over 2.5m when in use, with its optimum working length indicated by black stop lines on the tubes. The barrel and sliding caps are made of leather that is decorated with gold-tooled motifs. These include the letter 'L' under a crown on the sides and ends of the two caps. The lens mounts are made of turned wood. The length of the telescope when extended suggests that it was intended for astronomical use and would have been used with some form of support to hold it steady" (Royal Museums Greenwich).

Objective Notes:
Held in place with lignum vitae fitting, now glued in place. Heavily stopped down.


Caird Collection

Length (open): 2592

Length (closed): 700


Exit pupil:

Object status:

Optical Basics

Objective type: singlet

Optical style astronomical

Physical style

Functional style

Materials: leather, vellum, glass, wood, lignum vitae, parchment, pasteboard, gold tooling

Optical/Lab Data

Drawtube data:

physical lengths in mm:
starside to extension mark:
star-side tube diameter: 82
eye-side tube diameter:
ring diameter:

Drawtube notes:

Extends to more than 2.5m. End caps present. French text at end of main tube consistent with French style of telescope. Text might merit investigation for dating purposes.

Objective Data



652 ± -0.1 ± 0.3 ±
575 ± 0 ± ±
482 ± 2.3 ± 0.4 ±