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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.
Focal length; 27".O.G.diameter; 2.4".
caption: Night telescope | Publisher: | "http://collections.rmg.co.uk/" | Rights holder: | "Royal Museums Greenwich" | Subjects: | Vellum telescopes Night telescope | Source: | Royal Museums Greenwich | Identifier: | http://collections.rmg.co.uk/collections... | Go to resource |
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