Keep Clock Right Observations Fixed by Warner Thomas, Signed (1 results)

FIRST EDITION 1869. PRESENTATION COPY TO: "SIR J. F. W. HERSCHEL BART KH FRS FROM THE AUTHOR" (John Frederick William) IN INK TO TOP OF TITLE PAGE. Slim 8vo, pages: [3], 4-9, 60 tables, 61-66, original publisher's brown cloth, gilt title to upper cover, pale yellow endpapers. Covers have pale mottled fading, a few ink lines to lower cover, narrow pale red stain to top of first pastedown and endpaper, small bookplate to first pastedown, otherwise a good copy. An accomplished chemist, Herschel discovered the action of hyposulfite of soda on otherwise insoluble silver salts in 1819, which led to the use of "hypo" as a fixing agent in photography. In 1839, independently of William Henry Fox Talbot Herschel also invented a photographic process using sensitized paper. It was Herschel who coined the use of the terms in photography, of positive and negative to refer to photographic images. In 1820 he became a founding member of the Royal Astronomical Society. From 1833 until 1838, his astronomical investigations brought him and his family to the Cape of Good Hope in South Africa, where he met Julia Margaret Cameron, who became a lifelong friend. In 1850 Herschel was appointed Master of the Mint, but he resigned 6 years later due to poor health. His remaining years were spent working on his catalogues of double stars and of nebulae and star clusters. MORE IMAGES ATTACHED TO THIS LISTING, ALL ZOOMABLE, FURTHER IMAGES ON REQUEST. POSTAGE AT COST.