Page:Dictionary of National Biography volume 26.djvu/269

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Athenæum, 22 Jan. 1848 (‘Sir J. Herschel’); Revue Britannique, January 1848 p. 214, June 1876 p. 283.]

A. M. C.

HERSCHEL, Sir JOHN FREDERICK WILLIAM (1792–1871), astronomer, only child of Sir William Herschel [q. v.], was born at Slough on 7 March 1792. He was educated at Dr. Gretton's school at Hitcham, Buckinghamshire, then for a few months at Eton, and afterwards at home by Mr. Rogers, a Scottish mathematician. He entered St. John's College, Cambridge, at the age of seventeen, graduated thence in 1813 as senior wrangler and first Smith's prizeman, and was immediately elected to a fellowship in his college. He was at this time described by the poet Campbell as ‘a prodigy in science, and fond of poetry, but very unassuming’ (Beattie, Life of Campbell, ii. 234). He proceeded M.A. on 3 July 1816, and in occasional residences at the university during the interval formed a lifelong intimacy with Whewell. Their Sunday mornings' ‘philosophical breakfasts’ in 1815 were long remembered (Todhunter, Account of the Writings of Dr. Whewell, i. 6). Herschel's youthful compact with George Peacock [q. v.] and Charles Babbage [q. v.] to ‘do their best to leave the world wiser than they found it’ began to be fulfilled by their formation in 1813 of the ‘Analytical Society of Cambridge.’ The first volume of its transactions was written exclusively by Herschel and Babbage. A joint translation by Herschel and Peacock of Lacroix's ‘Elementary Treatise on the Differential Calculus,’ Cambridge, 1816, with an appendix on finite differences by Herschel, styled by Professor Tait ‘one of the most charming mathematical works ever written,’ became a university text-book, and was succeeded in 1820 by two admirable volumes of ‘Examples’ by Herschel and Babbage. To these works was mainly due the restoration of mathematical science in England by introducing the differential notation and continental methods of analysis.

Herschel's first communication to the Royal Society, ‘On a Remarkable Application of Cotes's Theorem’ (Phil. Trans. ciii. 8), was dated from Slough, 6 Oct. 1812, and on 27 May 1813 he was elected a fellow of the society. Several papers on various points of analysis followed, distinguished by the award of the Copley medal in 1821. That of 1816 (ib. cvi. 25), supplemented by an essay on the summation of series in the ‘Edinburgh Philosophical Journal’ in 1819 (ii. 23), was devoted to promote the new calculus of operations.

Gently combating his father's preference for the church, Herschel chose the law as his profession, and was entered as a student of Lincoln's Inn on 24 Jan. 1814. The acquaintance of Dr. Wollaston and of Mr. (afterwards Sir James) South diverted him, however, finally to science. He left London, and failing to obtain the chair of chemistry at Cambridge, experimented at Slough in chemistry and physical optics. Some of his original results were embodied in papers ‘On the Optical Phenomena exhibited by Mother-of-Pearl’ (ib. ii. 114), ‘On the Absorption of Light by Coloured Media’ (Trans. Roy. Soc. of Edinburgh, ix. 445), and in various researches on the action of crystals upon polarised light (Phil. Trans. cx. 45; Trans. Cambr. Phil. Soc. i. 21, 43).

Astronomy is first mentioned on 10 Sept. 1816, when he reported himself as ‘going under my father's direction to take up star-gazing.’ He then began a re-examination of his father's double stars, and executed in 1821–3 the revision of 380 pairs in conjunction with South, and at South's observatory in Blackman Street, Southwark. The instruments employed were a seven-foot and a five-foot refractor. The resulting catalogue (Phil. Trans. vol. cxiv. pt. iii.) was honoured by the bestowal of the Astronomical Society's gold medal, and of the Lalande prize for astronomy in 1825, for which Bessel, Struve, and Pons were competitors. Herschel took an active part in the foundation of the Royal Astronomical Society; he wrote its inaugural address, and was its first foreign secretary. He travelled in Italy and Switzerland with Babbage in 1821, making an ascent of Monte Rosa, and visited Holland with Grahame in 1822. After the removal of South's telescopes to Passy in 1824, he went abroad again with Babbage; and made a barometrical determination of the height of Etna on 3 July. He then traversed Germany, seeing some eminent astronomers, and visiting his aunt Caroline Herschel [q. v.] at Hanover. He experimented upon solar radiation from the summit of the Puy de Dôme in 1826. On his election in November 1824 as secretary of the Royal Society, a post filled by him during three years, he took up his residence at 56 Devonshire Street, Portland Place, London. On 18 April 1825 he wrote to his aunt, on receiving her zone catalogue of nebulæ: ‘These curious objects I shall now take into my especial charge, nobody else can see them.’ More than half of Sir William Herschel's 2,500 nebulæ were invisible with any existing telescope except the twenty-foot ‘front-view’ reflector constructed by Herschel with his father's aid in 1820. His first effective use of it was in executing a valuable drawing of the Orion nebula in February 1824 (Memoirs Astr. Soc.