Description
This stunning little telescope or ‘prospect glass’ is similar in design to the famous ‘little perspective’ advertised in John Yarwell’s late-17th century trade card. A similar example is held at the Science Museum, London, where it is dated c.1750 (inv. no. 1918-142). Little research has been carried out on this particular design, and an earlier date – potentially even late-17th century – is possible. Classical studies of early telescopes have tended to focus on astronomical instruments rather than small prospect glasses such as these. We have settled on 1720 as a best guess.
Condition is excellent: the optics are working and can be removed for examination. Focus is by a crude central screw. Magnification is low but the image produced is clear and distinct. The surface of the wood is nicely polished, noting only a few scratches; brass caps and lens holders are somewhat tarnished.
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Dealer information
Octavo Books
Small online bookstore specializing in the history of science, trading on ABEbooks since 2006: http://www.abebooks.co.uk/octavo-books-cambridge/50628664/sf