Description

From Bolton Hall, English, early 19th century, signed on the drawtube “Dollond, London,” on the eye surround “Robert Dymond, Bolton Hall,” and engraved on the dust cap with a heraldic fleur-de-lys. Made of brass with black enameled wood main tube, and opening from 7″ to 19-3/4″ (18 – 50 cm) by three drawtubes, the telescope is in fine condition and gives good images with its triplet achromatic objective and erecting eyepiece system in a segmented drawtube (PC/CC/CC/CC). The census records show one Robert Dymond born in Bolton in 1800, and by 1851 this Dr. Dymond living in Bolton Hall with his family and numerous servants.

“Little further improvement was made in the construction of the refracting telescope, till we come down to the time of Dollond and Ramsden,… when both parts of this instrument were brought nearly at the same time to almost a state of perfection. While Dollond was occupied in exterminating the prismatic colours from the compound object-glass, by means of a concave lens of flint glass interposed between two convex lenses of crown glass, Ramsden, his brother-in-law, succeeded in diminishing the aberrations both in the terrestrial and celestial eye-pieces; so that an union of the two improvements has rendered the achromatic refracting telescope as perfect as the materials of which it is composed will admit. It is a matter of much regret that large discs of flint-glass of uniform texture, of good colour, and free from veins, are extremely difficult to be acquired….” (Pearson, 1829)