Dollond, 1770 c.
National Maritime Museum Arrow right Arrow left
Photo

photo - whole telescope
Basic Info

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 #: NAV1664

Sources:

Royal Museums Greenwich. "Achromatic telescope". http://collections.rmg.co.uk/collections/objects/43876.html. [Accessed: June 2016].

Public Notes:

Museum Description:
"The octagonal barrel of this achromatic telescope is made of mahogany and is slightly tapered. It has a single brass draw tube and brass fittings, including a sliding eyepiece cover. The objective lens cap is missing. The maker’s name appears on the draw tube as ‘Dollond / London’" (Royal Museums Greenwich).

Length (open): 1275

Length (closed):

F-ratio:

Exit pupil:

Object status:

Optical Basics

Objective type: unconfirmed

Optical style

Physical style polygonal

Functional style

Materials: brass, glass, mahogany

Optical/Lab Data

Drawtube data:

Drawtube notes:

Diameter: 55 mm

Objective Data

Eyepieces

Notes:

WavelengthParaxial70%Whole
652 ± 5.9 ± 1.0 ± ±
575 ± 0 ± ±
482 ± -11.7 ± 1.0 ± ±