William Usherwood

William Usherwood (* 1820 ; † 1916 in Dorking (Surrey) , England ) was an English painter and photographer .

Live and act

William Usherwood was a portrait painter who painted portraits of Queen Victoria and Princess Alice for the Duchess of Gloucester . After the advent of photography he switched to the new art. From 1860 he owned a shop in Dorking near Reigate , Surrey , about 40 km south of London . In 1862 he was listed in the postal directory of his place of residence as a "portrait painter", in 1867 he was listed as a "portrait painter and photographer" and in 1874 only as a "photographer".

Usherwood had been married since 1843 and had 13 children. In 1913 he was able to celebrate their 70th wedding anniversary with his wife. He died in Dorking in 1916 at the age of 96.

Usherwood was probably the first person to photograph a comet . It was the comet C / 1858 L1 (Donati) . Usherwood used a portrait camera with a lens 3 ¼ "in diameter and 12" focal length (this corresponds to an aperture ratio of f / 3.7) with seven to nine seconds exposure time on a collodion plate of 9 " square . The picture showed both the comet's head and the tail. Neither the original plate nor the prints have been preserved from the photo.

Usherwood was no longer sure about the recording date and later stated September 27, 1858. If so, he predicted the US astronomer William Cranch Bond a day before, who took a picture through the telescope at Harvard College Observatory on September 28, but it only showed the comet's head. Only in 1881 was another comet photographed.

Individual evidence

1. ↑ JM Pasachoff, RJM Olson, ML Hazen: The earliest comet photographs: Usherwood, Bond, and Donati 1858. In: Journal for the History of Astronomy , XXVII, 1996, pp. 129-145 ( bibcode : 1996JHA .... 27 ..129P ).