Herschel, Alexander Stewart (DNB12)

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HERSCHEL, ALEXANDER STEWART (1836–1907), university professor and astronomer, second son of Sir John Frederick William Herschel, first baronet [q. v.], and grandson of Sir William Herschel [q. v.], was born on 5 Feb. 1836 at Feldhausen, South Africa, where his father was temporarily engaged in astronomical work. The family returned to England in 1838, and after some private education Alexander was sent to the Clapham grammar school in 1851, of which Charles Pritchard [q. v.], afterwards Savilian professor of astronomy, was headmaster. In 1855 he proceeded to Trinity College, Cambridge, where he graduated B.A. as twentieth wrangler in 1859, proceeding M.A. in 1877. While an undergraduate he helped Prof. Clerk Maxwell [q.v.] with his illustrations of the mechanics of rotation by means of the apparatus known as 'the devil on two sticks.' From Cambridge Herschel passed in 1861 to the Royal School of Mines, London, and began the observation of meteors which he continued to the end of his life. He early wrote, chiefly on meteorological subjects, papers for the British Meteorological Society, and he contributed, between 1863 and 1867, many articles to the 'Intellectual Observer,' a scientific periodical.

From 1866 to 1871 Herschel was lecturer on natural philosophy, and professor of mechanical and experimental physics in the University of Glasgow. From 1871 to 1886 he was the first professor of physics and experimental philosophy in the University of Durham College of Science, Newcastle-on-Tyne. At the Durham College Herschel provided, chiefly by his personal exertions, apparatus for the newly installed laboratory, some being made by his own hands. When the college migrated as Armstrong College to new buildings, the new Herschel Physical Laboratory was named after him.

Herschel made some accurate records of his observations of shooting stars in a long series of manuscript notebooks. He also accomplished important work in the summation, reduction, and discussion of the results of other observers with whom he corresponded in all parts of the world. With R. P. Greg he formed extensive catalogues of the radiant points of meteor streams, the more important of these being published in the 'Reports' of the British Association for 1868, 1872, and 1874. A table of the radiant points of comets computed by Herschel alone is in the 'Report' for 1875. He was reporter to the committee of the British Association on the 'observations of luminous meteors,' and from 1862 to 1881 drew up annually complete reports of the large meteors observed, and of the progress of meteoric science. For the British Association (1874–81) he prepared reports of a committee, consisting of himself, his colleague at Newcastle, Prof. A. G. Lebour, and Mr. J. T. Dunn, which was formed to determine the thermal conductivities of certain rocks. For the 'Monthly Notices' of the Royal Astronomical Society he prepared the annual reports on meteoric astronomy each February from 1872 to 1880 and contributed many other important papers to the 'Notices.' In one of these (June 1872), on meteor showers connected with Biela's comet, he predicted the shower which recurred at the end of November of that year. Herschel acquired great precision in noting the paths of meteors among the stars. From his determination of the radiant point of the November Leonids, Professor Schiaparelli deduced the identity of their orbit with that of Tempel's comet of 1866.

Besides meteoric astronomy, Herschel was interested in many branches of physical science, and became a member of the Physical Society of London in 1889 and of the Society of Arts in 1892. He contributed frequently to 'Nature,' an article on 'The Matter of Space' in 1883 being specially noteworthy. He worked much at photography, and in 1893 the Amateur Photographic Association presented an enlarged carbon print portrait of Alexander Herschel to the South Kensington Museum for the British Museum Portrait Gallery.

Herschel became fellow of the Royal Astronomical Society in 1867, and in 1884 was elected F.R.S., an honour already conferred on his grandfather, his father, and his younger brother John. In 1886 he gave up his professorship, and was made D.C.L. of Durham University. In 1888, with other members of his family, he reoccupied the house, now called Observatory House, Slough, where his grandfather. Sir William Herschel, had lived. Here he resided till his death, absorbed in study, but late in life he made a journey to Spain to observe the solar eclipse of 1905.

He died unmarried at Slough on 18 June 1907, and was buried in St. Lawrence's church, Upton, in the chancel of which his grandfather lies.

[Obituary notices in the Observatory Mag., July 1907, and Monthly Notices of the Royal Astronom. Soc, Feb. 1908; Annual Reports of the British Assoc]

H. P. H.