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Description: | IACOB CUNIGHAM 1661
NAHE - WEITH - OVERSICHTIG
This Galilean telescope has the name 'IACOB CUNIGHAM' and the date '1661' stamped onto the objective lens cap, making it one of the oldest dated telescopes in Britain.
The two draw tubes are made of wood covered in marbled vellum, while the barrel and lens caps are made of wood covered in red leather with gold-tooled decoration. The eyepiece tube also has three gold-tooled stop lines identified by the German words 'NAHE', 'WEITH' and 'OVERSICHTIG'. These indicate different focusing lengths and suggest that the telescope was probably made in Germany. Jacob Cunigham may have been either the maker or the original owner of the telescope. The larger draw tube also has a single gold-tooled stop line.
The curious shape of the barrel is designed to accommodate a large objective glass. At this time it was easier to grind a large lens than a small one. Brass diaphragms over the end of each lens have been used to reduce their apertures.
Focal length; 24". O.G.diameter: 3.1"
Diameter: 78 mm (objective lens); 40 mm (objective lens aperture); 17 mm (eyepiece aperture).
Note: lenses are not original.
Observation by Stuart Talbot: the Object-Glass diaphragm aperture is hand-cut from hand-beaten brass-plate; of period butter-coloured brass and of such a restricted diameter that I believe it may be the original. The sprung brass lens retaining-ring colour-matches the diaphragm. The eyepiece diaphragm is modern - the sprung brass lens retaining-ring however could be original.
caption: Portable telescope
caption: Portable telescope and lid
caption: Telescope - inscription on draw tube
caption: Telescope - lid | Publisher: | "http://collections.rmg.co.uk/" | Rights holder: | "Royal Museums Greenwich" | Subjects: | Jacob Cunigham Collections Blog Galilean telescopes Galilean telescope | Source: | Royal Museums Greenwich | Identifier: | http://collections.rmg.co.uk/collections... | Go to resource |
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