Unknown, 1750 c.
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Photo

photo - eyepiece
Basic Info

Maker: Unknown

Year: 1750 c.

Year Range: -

Year Notes:

Manufacturing Location: Venice, Italy

Signature:

Signature Notes:

Inscriptions:

No stand present.

Collection: National Maritime Museum

Accession #: NAV1495

Sources:

Royal Museums Greenwich. "Hand-held telescope". http://collections.rmg.co.uk/collections/objects/43707.html. [Accessed June 2016]

Public Notes:

Museum Description:
"This non-achromatic telescope has three draw tubes. The barrel is made of pasteboard and is decorated with hand-painted flowers on a red background. The other fittings are made of turned horn. The objective lens and the screw-on eyepiece cap are now missing. Early telescope lenses suffered from the appearance of coloured fringes, a problem that could be reduced by using lenses with long focal lengths. This meant, however, that the telescopes had to be very long - the stop lines drawn onto the draw tubes of this telescope indicate an optimum working length of about 918 mm" (Royal Museums Greenwich).

Provenance:

Caird Collection

Length (open): 330

Length (closed): 918

F-ratio:

Exit pupil:

Object status:

Optical Basics

Objective type: N/A

Optical style

Physical style

Functional style

Materials: pasteboard, horn, bone, glass

Optical/Lab Data

Drawtube data:

Drawtube notes:

Overall: 320 mm; Tube Diameter: 35 mm

Objective Data

Eyepieces

Notes: