British mathematician, astronomer, and inventor (1792–1871) known for his discoveries related to the moons of Saturn and Uranus and for his pioneering work in early photographic processes, including coining the word ‘photography’ itself. ALS signed “JFW Herschel,” one page both sides, 4.5 x 7, May 20, 1843. Letter to an unidentified gentleman. In full: “I beg to thank you for your account of The Aurora. I cannot account for the apparent fixity of the luminous patches as seen by you contrasted with their southward movement here. The low arch showed here might rise to 10° altitude. As you saw it at 30° from Durham it would seem to have been vertical over South Yorkshire and somewhere about 38 miles high. The magnet was more affected at Kelso then at any period since the observations commenced—3 years or more.” In fine condition, with intersecting folds, writing lightly showing through from opposing sides, and a light block of toning to signed page, some extending lightly over the signature.
The Aurora Borealis witnessed by Herschel and countless others two weeks before this letter was composed is considered by astronomers to have been one of the most brilliant displays known—and one that Herschel said was the greatest he had witnessed. RR Auction COA.