Page:Dictionary of National Biography volume 02.djvu/443

 lies in question might be due to the radiation of heat from the leaden masses employed to deflect the pendulum, and proposed gilding both them and the torsion-box. The remedy was completely successful; and the process begun de novo in January 1841 was conducted to a successful issue. The printed observations numbered 2,153 (besides upwards of a thousand rejected as untrustworthy), varying in duration from ten to thirty minutes. This memorable labour was rewarded with the Royal Astronomical Society's gold medal (of which Baily thus for the second time became the recipient) 10 Feb. 1843.

The few noteworthy observations of the heavens made by Baily referred, singularly enough, to the subject of his first astronomical investigation. On 15 May 1836, while watching an annular eclipse of the sun at Inch Bonney, near Jedburgh, he witnessed a phenomenon to which he first directed explicit attention, and which, from his vivid description, received the name of ‘Baily's Beads.’ It consists in the breaking up of the fine solar crescent visible at the beginning and end of central eclipses into a row of lucid points, the intervals separating which at times appear to be drawn out, as the moon advances, into dark lines or belts; the whole being a combined effect of irradiation and the inequalities of the moon's edge. Baily's narrative (Mem. R. A. S. x. 1) excited strong interest, and effectively roused astronomers to the importance of eclipses under their physical aspect, that of 8 July 1842 being at his suggestion prepared for with this view. Baily observed it from an empty room in the university of Pavia, with the same instrument (a 3½-foot Dollond's achromatic) used at Inch Bonney. The ‘beads’ were less conspicuous than before; but he was (in his own words) ‘electrified’ by the unexpected and ‘appalling’ splendour of the corona, through which rose three vast prominences resembling the ‘snowy tops of Alpine mountains when coloured by the rising or the setting sun’ (Mem. R. A. S. xv. 6). But towards the solution of the magnificent problem thus presented to science he did not live to see any advance made.

In June 1841 he was knocked down by a furious rider while crossing Wellington Street, and lay for a week senseless. Nevertheless, he completely recovered, and was able to resume his experiments in weighing the earth by the end of September. It was not until the spring of 1844 that his health, until then remarkably stable, finally gave way, although he rallied sufficiently to attend commemoration at Oxford, when an honorary degree of D.C.L. (previously, in 1835, received from the university of Dublin) was conferred upon him, in company with Airy and Struve. Soon after his return to London, however, an internal complaint became manifest, and he sank gradually and without pain, expiring 30 Aug. 1844, aged 70. He was at the time president of the Royal Astronomical Society.

The abilities of Francis Baily were not of the highest order. As a mathematician his range was a limited one. He never mastered the refinements of modern analysis, and was frequently indebted to the aid of Professors Airy and De Morgan in working out his investigations. Nor was his mind visited by any of the luminous inspirations of genius. Yet his life presents an almost unique example of laborious usefulness to science. More than to any single individual, the rapid general advance of practical astronomy in the British islands was due to him. To clear discernment of the precise wants of his time he joined untiring activity in supplying them. His organising energy was guided by a tact which rendered it irresistible. Add a rare faculty of order and concentration, with a perfect knowledge of and complete mastery over his powers, and the sources of his almost unparalleled effectiveness as a worker become in some degree apparent. Besides the special tasks executed by him with astonishing thoroughness, precision, and rapidity, he took a leading part in the general conduct of scientific affairs. He was unfailing at the annual visitation of the Royal Observatory during twenty-seven years. He succeeded Babbage in 1839 as permanent trustee of the British Association, and had belonged to its council for two years previously. He aided in the foundation (in 1830) and became vice-president of the Geographical Society, acted, during considerable periods, as vice-president and treasurer of the Royal Society, generally held a seat on the council, and rarely missed one of its meetings from the date of his election as fellow, 22 Feb. 1821. Scientific distinctions were showered upon him. He was a fellow of the Linnean and Geological societies, a corresponding member of the Institute of France, of the Academies of Berlin, Naples, and Palermo, and was enrolled on the lists of the American and Royal Irish Academies. Few men have left behind them so enviable a reputation. He was gentle as well as just; he loved and sought truth; he inspired in an equal degree respect and affection. He was never married; and his sister, Miss Elizabeth Baily (who survived him fifteen years), superintended his hospitable establishment.

[Sir J. Herschel, in Memoirs R. Astr. Soc. xv. 311, published separately under the title Memoir