Maker: Dollond

Year: 1770 c.

Year Range: -

Year Notes:

Manufacturing Location: London, England

Signature: DOLLOND / LONDON

Signature Notes:

Inscriptions:

No stand present.

Collection: National Maritime Museum

Accession #: NAV1520

Sources:

Royal Museums Greenwich. "achromatic telescope". http://collections.rmg.co.uk/collections/objects/43732.html [Accessed: June 2016].

Public Notes:

"The barrel of this hand-held telescope is covered in rayskin (shagreen) that has been dyed green, while the three draw tubes are made of green vellum. Stop lines marked with dots on the draw tubes indicate the optimum working length of the telescope. The brass fittings include sliding eyepiece and objective lens covers. The telescope has an achromatic objective lens, the patent for which was taken out by John Dollond (1706–61) in 1758. John's son, Peter (1731–1820), had founded the company whose name is stamped on one of the draw tubes: 'DOLLOND / LONDON'" (Royal Museums Greenwich).

Length (open): 697

Length (closed): 242

F-ratio:

Exit pupil:

Object status:

Objective type: doublet (unknown)

Optical style

Physical style spyglass

Functional style

Materials: brass, shagreen, vellum, glass, wood, pasteboard

Drawtube data:

Drawtube notes:

Diameter: 45 mm

Objective Data

Eyepieces

Notes: