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Selection of eyepieces and other accessories in fitted mahogany case for (Smyth) refracting telescope

1830
Smythian telescope, c.1824, a refractor of 3 3/4 inch aperture and 50 inch focal length by Thomas Robinson, Portland Place, London with optics by Charles Tulley in fitted box but without equatorial mount or stand. Separate fitted box contains 6 astronomical eyepieces, terrestrial eyepiece, cometary eyepiece, filter wheel, Herschel wedge, split-lens micrometer by Dollond, double-image micrometer by Thomas Robinson and related items including an occulting bar, graticle and ring (annular) micrometer. First used by Capt. W. H. Smyth at Bedford then given by him to Dr Lee at Hartwell House in 1828, later used by Dr N R Pogson from 1857 until 1860 at the Radcliffe and Hartwell Observatories and then at the Madras Observatory, India until 1891. Presented to the British Astronomical Association by the widow of Dr C. Michie Smith.

Smythian telescope, c.1824, a refractor of 3 3/4 inch aperture, 50 inch focal length, and accessories

1825-1829
Split-lens eyepiece position micrometer with spherical crystal micrometer and eyepiece dynameter, all by George Dollond, London in fitted mahogany box, 1820-1830.

Split-lens eyepiece position micrometer with spherical crystal micrometer and eyepiece dynameter

1820-1830
Eyepiece double-image spherical crystal micrometer using a made by George Dollond in 1830 for the Smyth telescope (1929-949 Pt1 ). Captain W.H.Smyth used this Crystal micrometer to measure double stars for his famous book, 'A Cycle of Celestial Object' first published in 1844. The novel design of the instrument caused ambiguity in his readings which after his death resulted in accusation of inaccuracy and plagiarism. Charges that were shown subsequently to be unfounded (see 'An Astronomical Scrapbook' by Joseph Ashbrook, Cambridge 1984).

Eyepiece double-image spherical crystal micrometer

1830