Ranyard, Arthur Cowper (DNB00)

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RANYARD, ARTHUR COWPER (1845–1894), astronomer, born at Swanscombe, Kent, was son of Benjamin Ranyard by his wife Ellen Henrietta, who is separately noticed. Ranyard attended University College school, London, from 1857 to 1860, afterwards proceeding to University College. Here the influence of Professor De Morgan led him to concentrate his attention on mathematics and astronomy, and he formed an intimate friendship with the professor's son George. In 1864 the two friends formed the plan for a society for the special study of mathematics, and issued a circular inviting attendance at the first meeting of ‘the University College Mathematical Society’ on 7 Nov. 1864. The first meeting mentioned in the minutes of the society, however, was held on 16 Jan. 1865, when Professor De Morgan was elected president, and Messrs. Cozens-Hardy and H. M. Bompas secretaries. After the president's inaugural address Ranyard read the first paper, ‘On Determinants.’ The new association received the support of eminent mathematicians, and ultimately developed into the present London Mathematical Society.

Proceeding to Cambridge, Ranyard entered Pembroke College in October 1865, and graduated M.A. in 1868. Adopting the law as his profession, he was called to the bar (Lincoln's Inn) in 1871; but his tastes lay in the direction of science, and his means enabled him to devote much of his time to astronomy. He became a fellow of the Royal Astronomical Society in 1863, was a member of the council (1872–88 and 1892–4), and was secretary (1874–80). He was assistant secretary of the expedition for observing the total solar eclipse of 1870, and made a successful series of polariscopic observations at Villasmunda in Sicily (Memoirs Royal Astr. Soc. vol. xli.) In 1878 he went to Colorado to view the solar eclipse of that year, which he observed and photographed at a station near Denver (ib. xlvi. 213). In 1882 he observed and photographed the total solar eclipse at Sohag in Upper Egypt. His most extensive work in astronomy was the eclipse volume of the Royal Astronomical Society (ib. vol. xli.), in which are systematised and discussed the observations of all solar eclipses down to 1878. It was originally commenced in conjunction with Sir George Airy, but soon devolved upon Ranyard alone. Commenced in 1871, it was completed in 1879.

In 1888 his friend Richard Anthony Proctor [q. v.] died, leaving his great work, ‘Old and New Astronomy,’ incomplete, and Ranyard generously undertook to finish it for the benefit of the author's family. The chapters which are entirely by Ranyard are those on the universe of stars, the construction of the milky way, and the distribution of nebulæ, which he discussed with much ability and thoroughness. He also succeeded Proctor as editor of ‘Knowledge,’ to which he contributed a long series of articles upon the sun and moon, the milky way, the stellar universe, star-clusters, the density of nebulæ, &c. These papers give his mature views upon many intricate problems. His most important investigations were those upon nebulæ, the density of which he concluded to be extremely low, even as compared with the earth's atmosphere, and upon star-clusters, which he regarded as showing evidence of the ejection of matter from a centre, and not gradual condensation, as supposed by Laplace (Knowledge, vols. xvi. xvii.)

Although mainly engaged in scientific pursuits, he took much interest in public affairs, and in 1892 was elected a member of the London County Council, where he did important work, especially in connection with the new (London) Building Act, which passed into law in the summer of 1894.

In 1872 he made, in conjunction with Lord Lindsay (the twenty-sixth Earl of Crawford), experiments on photographic irradiation (Monthly Notices Royal Astr. Soc. xxxii. 313), and in 1886 he investigated the relation between brightness of object, time of exposure, and intensity of photographic action (ib. xlvi. 305).

Ranyard, who was unmarried, lived a somewhat retired life of laborious industry. He was a man of generous spirit, extremely conscientious, and completely devoted to duty. He died of cancer, at his house in Hunter Street, Brunswick Square, on 14 Dec. 1894. A portrait is given in ‘Knowledge’ for February 1895.

[Men of the Time; Life of A. De Morgan, p. 281; Knowledge, vols. xii.–xvii.; Royal Society Catalogue of Scientific Papers, vol. viii.]

W. H. W.