Maker: Unknown

Year: 1710 c.

Year Range: 1662-1750

Year Notes: Huygens eyepiece provides earliest date estimate.

Manufacturing Location: Italy or France

Signature:

Signature Notes:

Inscriptions:

No stand present.

Collection: National Maritime Museum

Accession #: NAV1578

Sources:

Royal Museums Greenwich. "Night telescope". http://collections.rmg.co.uk/collections/objects/43790.html. [Accessed: June 2016].

Public Notes:

Update 2016: Features a Huygens eyepiece (2 lenses).

Eyepiece Notes: Huygens eyepiece.

Museum Description:
"This non-achromatic telescope has a leather-covered barrel and a single draw tube made of green vellum. The fittings are of boxwood and brass, including a sliding eyepiece cover. The screw-on objective lens cap is now missing. A ring of black dots on the draw tube acts as a stop line, indicating the approximate working length of the telescope. It has a large non-achromatic objective lens to allow as much light as possible to enter the telescope. The telescope doesn’t have extra lenses to correct the inversion of the image, since the more lenses a telescope has, the greater the loss of light. The production of inverted images is typical of night telescopes" (Royal Museums Greenwich).

Length (open): 640

Length (closed):

F-ratio:

Exit pupil:

Object status:

Objective type: singlet

Optical style other and astronomical

Physical style

Functional style night

Materials: leather, vellum, boxwood, glass, wood, brass

Drawtube data:

physical lengths in mm:
starside to extension mark:
star-side tube diameter: 95
eye-side tube diameter:
ring diameter:

Drawtube notes:

Objective Data

Eyepieces

Notes: