Maker: Unknown

Year: 1750 c.

Year Range: -

Year Notes:

Manufacturing Location: England

Signature:

Signature Notes:

Inscriptions:

No stand present.

Collection: National Maritime Museum

Accession #: NAV1576

Sources:

Royal Museums Greenwich. "Polygonal telescope". http://collections.rmg.co.uk/collections/objects/43788.html [Accessed: June 2016].

Public Notes:

"This non-achromatic telescope has an octagonal barrel covered in rayskin. The barrel unscrews into two sections. There is a single draw tube made of vellum, which has stop lines drawn onto it to indicate the different working lengths of the telescope according to the distance of the object being viewed. There is also some tooled decoration on the draw tube. The other fittings are of ivory, although parts of the eyepiece assembly are missing. The objective lens is a modern replacement. The telescope is thought to have belonged to Admiral Augustus Keppel (1725-86)" (Royal Museums Greenwich).

Provenance:

Augustus Keppel

Length (open): 1556

Length (closed): 1447

F-ratio:

Exit pupil:

Object status:

Objective type: unconfirmed

Optical style

Physical style polygonal

Functional style

Materials: ivory, rayskin, vellum, glass

Drawtube data:

Drawtube notes:

Diameter: 45 mm (barrel); 57 mm (max)

Objective Data

Eyepieces

Notes: