Herschel, SIR WILLIAM, born at Hanover, November 15, 1738, was the son of a band-master, and was educated as a professional musician. He first visited England as a member of the band of the Hanoverian Guards; but in 1757 he established himself in England, becoming a teacher of music in the town of Leeds, whence he went to Halifax as organist, and subsequently (1766) in the same capacity to Bath. Here he would seem to have first turned his attention to astronomy. Wanting a superior telescope, and unable to afford to buy a good reflector, he made one for himself—a Newtonian, of 5 feet focal length, and with this applied himself to study the heavens. In 1781 he made his first discovery, being a new planet, which at first he took for a comet. It was detected by an exhaustive process of surveying the heavens, which Herschel was the first to follow, taking the stars in regular series, and examining them all in their groups through the same instrument. The result of his discovery was his appointment to be private astronomer to George III., with a salary of £200 (afterwards £250) a year. He then went to live at Slough, near Windsor, where, assisted by his sister Caroline, he continued his researches. Herschel married a Mrs Mary Pitt, and left one son, John. He was knighted by George III., and made a D.C.L. by the university of Oxford; he became rich partly through his wife's jointure, and partly through selling mirrors for reflecting telescopes. He died at Slough, 25th August 1822.
Herschel contributed sixty-nine papers to the Philos. Trans. between the years 1780 and 1815; and to the first vol. of Mem. of the Astron. Society he contributed a paper 'On the Places of 145 New Double Stars.' He greatly added to our knowledge of the solar system: he discovered Uranus (called by him Georgium Sidus) and what he took for its six satellites, and two satellites of Saturn. Besides this he detected the rotation of Saturn's ring, the period of rotation of Saturn itself and that of Venus, the existence of the motions of binary stars, the first revelation of systems besides our own. He extended our knowledge of the Milky Way and the constitution of nebulae, and, in fact, was the first to give the human mind any conception of the immensity of the universe. His catalogue of double stars, nebulae, &c., and tables of the comparative brightness of stars, and his researches in regard to light and heat would of themselves entitle him to the first rank as an astronomer and natural philosopher. He erected a famous monster telescope of 40 feet length. It was begun 1785, and finished 1789, in which year he by means of it detected the sixth satellite of Saturn. See Herschel's Life and Works, by E. S. Holden (New York, 1881).
His sister, CAROLINE LUCRETIA, was born 16th March 1750, and lived in Hanover till 1772, when she came to England to live with her brother at Bath. When William turned astronomer she became his constant helper; and on his being appointed private astronomer to George III. she acted as his assistant, doing all the duties of an assistant-astronomer, and in that character receiving a small salary from the king. While discharging her duties in this position she found time for a series of independent observations with a small Newtonian telescope, made for her by her brother. Her special business was to sweep the heavens for comets, eight of which she discovered, in regard to five of which she has the credit of priority of discovery; and several remarkable nebulae and clusters of stars included in William's catalogues were described from her original observations. In 1798 she published, at the expense of the Royal Society, A Catalogue of Stars taken from Mr Flamsteed's Observations, which contained 561 stars omitted in the British catalogue. She lived with her brother during the whole of his career, sharing his labours and distinctions, and on his death returned to her native country. She was then seventy-two years of age, but she lived to be ninety-eight, retaining all her faculties to the last. In 1828 the Astronomical Society conferred on her their gold medal, and she was an honorary member of the society. She died 9th January 1848. See her Memoir and Correspondence, edited by Mrs Herschel (1876).
SIR JOHN FREDERICK WILLIAM HERSCHEL, the only son of Sir William, was born at Slough, 7th March 1792, and educated at Eton and St John's, Cambridge, where, in 1813, he was senior wrangler and first Smith's prizeman. His first publication was A Collection of Examples of the Application of the Calculus of Finite Differences (1820). In 1822 he applied himself especially to astronomy, using his father's methods and instruments in observing the heavens. For a time he worked with Sir James South in re-examining the nebulae and clusters of stars described in his father's catalogues. The results of the re-examination were given in 1833 to the Royal Society in the form of a catalogue of stars in order of their right ascension. The catalogue contained observations on 525 nebulae and clusters of stars not noticed by his father, and on a great number of double stars—in all between 3000 and 4000. This important contribution to science led to his being acknowledged as the worthy successor of his father; so early, indeed, as 1826 the Royal Society had voted to him and South a gold medal apiece for their observations on double stars; but by 1833 his pre-eminence was beyond the necessity of being marked by acknowledgments. His treatises on Sound and on the Theory of Light had appeared in the Encyclopædia Metropolitana (1830-31); his treatise on Astronomy (1831) and the 'Preliminary Discourse on the Study of Natural Philosophy' in Lardner's Cyclopædia; not to mention his papers in the Transactions of the Astronomical Society. In January 1834 Herschel arrived at the Cape of Good Hope, with the intention of completing the survey of the sidereal heavens, by examining the southern hemisphere as he had done the northern. Here he established his observatory at Feldhausen, six miles from Table Bay; and in four years, working all the time at his own expense, he completed his observations. The public interest taken in his labours was, as might be supposed, very great; but though now and then gratified by partial statements of his results, it was not till 1847, nine years after his return from the Cape, that it received full gratification in the publication of a volume of Astronomical Observations made at the Cape; being the Completion of a Telescopic Survey of the whole Surface of the Visible Heavens commenced in 1825. It need not be said that the results of these labours are invaluable. They are now incorporated into all books on astronomy. Herschel, when at the Cape, gave an impulse to the science of meteorology, having the merit of having suggested the scheme for taking meteorological observations simultaneously at different places.
On his return to England honours were showered on him—he was made D.C.L. of Oxford, and, on the Queen's coronation, a baronet. He was president of the Astronomical Society, and in 1849 became Master of the Mint. His articles on Meteorology, Physical Geography, and Telescope, contributed to the Encyclopædia Britannica, were published separately; and his Popular Lectures on Scientific Subjects (new ed. 1880) and Collected Addresses are well-known works. Herschel was also a distinguished chemist, and attained important results in photography independent of Fox Talbot. His researches on the undulatory theory of light were very valuable. He had also a profound interest in poetry, and made translations from Schiller and from the Iliad. He died at Collingwood, in Kent, on 12th (not 11th) May 1871, and was buried in Westminster Abbey near Sir Isaac Newton. See Agnes M. Clerke, The Herschels and Modern Astronomy (1896).