Dollond, 1760 c.
National Maritime Museum Arrow right Arrow left
Photo

photo - whole telescope
Basic Info

Maker: Dollond

Year: 1760 c.

Year Range: -

Year Notes:

Manufacturing Location: London, England

Signature: Dollond / London

Signature Notes:

Inscriptions:

No stand present.

Collection: National Maritime Museum

Accession #: NAV1656

Sources:

Royal Museums Greenwich. "Polygonal telescope". http://collections.rmg.co.uk/collections/objects/43868.html [Accessed: June 2016].

Public Notes:

"This achromatic telescope has a decagonal mahogany barrel that tapers and a single brass draw tube without a mechanical stop. The other brass fittings include a pivoted eyepiece cover, but the objective lens cap is now missing. The maker's name is inscribed on the draw tube as 'Dollond London'. The telescope is said to have belonged to Lord Howe (1726-99), who became First Lord of the Admiralty in 1783. For a portrait of Lord Howe see BHC2790 and for his sword see WPN1249" (Royal Museums Greenwich).

Provenance:

Richard Howe

Length (open): 753

Length (closed): 645

F-ratio:

Exit pupil:

Object status:

Optical Basics

Objective type: doublet (unknown)

Optical style

Physical style polygonal

Functional style

Materials: mahogany, brass, glass

Optical/Lab Data

Drawtube data:

Drawtube notes:

Diameter: 43 mm (barrel), 45 mm (max.)

Objective Data

Eyepieces

Notes:

WavelengthParaxial70%Whole
652 ± -.1.6 ± 0.3 ± ±
575 ± 0 ± ±
482 ± 5.0 ± 0.2 ± ±