Herschel wrote many papers and articles, including entries on meteorology, physical geography and the telescope for the eighth edition of the
Encyclopædia Britannica. He also translated the
Iliad of Homer. In 1823, Herschel published his findings on the optical spectra of metal salts. Herschel invented the
actinometer in 1825 to measure the direct heating power of the Sun's rays, and his work with the instrument is of great importance in the early history of
photochemistry. of a model of the lunar crater Copernicus, 1842. Photographs of the Moon's surface were not yet possible at the time Herschel proposed a correction to the Gregorian calendar, making years that are multiples of 4000
common years rather than
leap years, thus reducing the average length of the
calendar year from 365.2425 days to 365.24225. Although this is closer to the
mean tropical year of 365.24219 days, his proposal has never been adopted because the
Gregorian calendar is based on the mean time between vernal
equinoxes (currently days). Herschel was elected a Foreign Honorary Member of the
American Academy of Arts and Sciences in 1832, and in 1836, a foreign member of the
Royal Swedish Academy of Sciences. In 1835, the
New York Sun newspaper wrote a series of satiric articles that came to be known as the
Great Moon Hoax, with statements falsely attributed to Herschel about his supposed discoveries of animals living on the Moon, including batlike winged humanoids. Several locations are named for him: the village of
Herschel in western
Saskatchewan,
Canada, site of the discovery of
Dolichorhynchops herschelensis, a type of
plesiosaur;
Mount Herschel in
Antarctica; the crater
J. Herschel on
the Moon; and the settlement of
Herschel, Eastern Cape and the
Herschel Girls' School in
Cape Town, South Africa. While it is commonly accepted that Herschel Island, in the Arctic Ocean, part of the
Yukon Territory, was named after him, the entries in the expedition journal of Sir
John Franklin state that the latter wished to honour the Herschel family, of which John Herschel's father, Sir
William Herschel, and his aunt,
Caroline Herschel, are as notable as John. ==Family==