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Date: |
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Description: | DOLLOND / LONDON
DOUANE CENTRALE / EXPORTATION / PARIS
The telescope barrel is covered with rayskin (shagreen) that has been dyed green. There are four draw tubes made of green vellum with stop lines (shown by rings of black dots) that indicate the optimum working length of the telescope. The brass fittings include a screw-on objective lens cap and a sliding eyepiece cover.
The telescope has an achromatic objective lens. The achromatic lens was first patented in 1758 by John Dollond (1706?61). It was his son, Peter (1731?1820), who founded the company whose name is engraved on one of the draw tubes: 'DOLLOND / LONDON'.
Focal length; 65". O.G.diameter; 1.8".
caption: Portable telescope
caption: Portable telescope- draw tube inscription | Publisher: | "http://collections.rmg.co.uk/" | Rights holder: | "Royal Museums Greenwich" | Subjects: | Rayskin (shagreen) Vellum Achromatic lens achromatic telescopes Dollond & Aitchison Peter Dollond | Source: | Royal Museums Greenwich | Identifier: | http://collections.rmg.co.uk/collections... | Go to resource |
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