A fine example of a Dollond portable, folding and achromatic telescope in brass, circa 1790. The instrument is nicely signed “Dollond London”.
This model of folding telescope was invented by Ramsden around 1780 and Dollond and Ribright also made it in the late 18th century (see the example by Ribright, in Louwamn, A certain instrument for seeieng far, number 161 page 144).
The optics of this model is very interesting, combining a four-lense refractor eyepiece and a three-lens objective.
The telescope measures 17,7 cm closed when all parts are stored inside the main tube.
Indeed, this is a folding and portable diminutive example : the tripod stand and the main pillar can be stored in the inner tube which can itself be stored in the main tube. Everything forming a small portable cylinder.
Very fine working condition.
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Established by Alexandre Piffault in 2014 and based in Paris at 5 rue de Condé, 75006, very close to Odéon, Le Zograscope specializes in antique and rare books in Science, Medicine and Technology, and rare antique instruments in the same fields. We have especially a strong interest in early and continental microscopy, early and special mathematical/drawing instruments, medical and surgical instrument, and rare technology.