John Herschel
1839, 9 September (taken) 1890 (print)
The Forty-Foot Telescope at Slough

Photographic print
Dominic Winter Book Auctions
Photography: The First 150 Years, 9 March 2018, Lot: 201
 
Photographic print made in 1890 [by John Werge] from John Herschel's glass negative of [9 September] 1839, circular silver print (diameter 92mm), some small areas of abrasions or insect damage to paper surface, mounted on paper support incorporating printed title and descriptive letterpress and dated August 1890, with signatures of Herschel's two sons, mounted on card, framed in period wooden frame, glazed, contemporary Ryman & Co. stationery label (split) and fragment of related (or original) printed paper descriptive notice to frame verso, overall 40 x 49cm.
 
This is one of only 25 prints made in 1890 from the original negative, the earliest surviving photograph on glass. This was the only image recorded of the 40-foot telescope in Slough, Berkshire, assembled in 1787 by William Herschel (1738-1822), and dismantled in 1839. The massive reflecting telescope used a metal mirror four feet in diameter and weighed over a ton, and became a much-visited wonder of the age. By the time Herschel's son John took this photograph, the telescope structure had become unsafe through neglect. The photograph is mounted in a frame using the rungs from John Herschel's telescope used at Slough and Cape Town, South Africa. The negative, now faded almost beyond recognition, is preserved in the collections of the Science Museum, London.
 
LL/82024