Unknown, 1750 c.
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Photo

photo - whole telescope
Basic Info

Maker: Unknown

Year: 1750 c.

Year Range: -

Year Notes:

Manufacturing Location:

Signature:

Signature Notes:

Inscriptions:

No stand present.

Collection: National Maritime Museum

Accession #: NAV1509

Sources:

Royal Museums Greenwich. "Hand-held telescope". http://collections.rmg.co.uk/collections/objects/43721.html [Acceessed: June 2016].

Public Notes:

"This non-achromatic telescope has a leather barrel decorated with gold-tooled motifs. There are three draw tubes made of marbled paper. The other fittings are of turned ivory, including a screw-on cap for the objective lens (the eyepiece cap is missing). Telescopes in this period had to be quite 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. Stop lines drawn onto the draw tubes of this telescope indicate an optimum working length of about 812 mm" (Royal Museums Greenwich).

Length (open): 812

Length (closed): 325

F-ratio:

Exit pupil:

Object status:

Optical Basics

Objective type: N/A

Optical style

Physical style

Functional style

Materials: vellum, leather, ivory, gold tooling, wood, glass

Optical/Lab Data

Drawtube data:

Drawtube notes:

Diameter: 48 mm

Objective Data

Eyepieces

Notes: