numerical form, at any cost of labour. … To one who had known, in some degree, of the enormous quantity of arithmetical work which he had turned out, and the unsparing manner in which he had devoted himself to it, there was something very pathetic in his discovery, towards the close of his long life, that "the figures would not add up"' (Autobiography of Sir George Biddell Airy, p. 3).
The amount of his labours almost exceeds belief. On the literary side alone they have rarely been equalled. He published eleven separate volumes, including treatises on 'Gravitation' (1834 and 1884), on 'Trigonometry' written for the Encyclopædia Metropolitana about 1825 and reprinted in 1855), on 'Partial Differential Equations' (1866), 'On Sound and Atmospheric Vibrations' (1868 and 1871). His 'Popular Astronomy,' embodying six lectures delivered at Ipswich in 1848, passed through twelve editions. And the papers contributed by him to journals and scientific collections numbered 377, besides 141 official reports and addresses. He wrote on 'The Figure of the Earth,' and on 'Tides and Waves,' in the 'Encyclopaedia Metropolitana;' his 'Report on the Progress of Astronomy,' drawn up for the British Association in 1832, is still valuable; he gave the first theory of the diffraction of object-glasses in an essay read before the Cambridge Philosophical Society on 24 Nov. 1834; for his discussion of the 'Laws of the Tides on the Coasts of Ireland' (Phil. Trans. 12 Dec. 1844) he was awarded a royal medal by the Royal Society in 1845; he communicated important researches on ancient eclipses to that body in 1853, and to the Royal Astronomical Society in 1857; and he introduced in 1859 a novel method of dealing with the problem of the sun's translation (Memoirs of the Royal Astronomical Society, xxviii. 143).
Airy left six children, his three eldest having died young. His third son, Mr. Osmund Airy, was appointed government inspector of schools in 1876; his daughter Hilda married, in 1864, Dr. Routh of Cambridge.
[Airy left a detailed autobiography, which was published at Cambridge in 1896, under the editorship of his eldest son, Mr. Wilfrid Airy, with the additions of a personal sketch and a complete bibliographical appendix. A portrait is prefixed, copied from a steel-engraving executed by C. H. Jeens in 1878 (Nature, xviii. 689). The following sources of information may also be consulted: Proceedings Royal Soc. li. 1 (E. J. Routh); Monthly Notices, lii. 212; Observatory, xv. 74 (E. Dunkin), with a photograph taken on his ninetieth birthday; Nature, 31 Oct. 1878 (Winnecke), 7 Jan. 1892; Times, 5 Jan. 1892; English Mechanic, 8 Jan. 1892; Grant's Hist. of Physical Astronomy; Graves's Life of Sir William Rowan Hamilton, passim.]
AITCHISON, Sir CHARLES UMPHERSTON (1832–1896), lieutenant-governor of the Panjáb, born in Edinburgh on 20 May 1832, was the son of Hugh Aitchison of that city, by his wife Elizabeth, daughter of Charles Umpherston of Loanhead near Edinburgh. He was educated in the high school and university, where he took the degree of M.A. on 23 April 1853. While a student in the university of Edinburgh, Aitchison attended the lectures of Sir William Hamilton (1788-1856) [q. v.] on logic and metaphysics. He afterwards passed some time in Germany, where he studied the works of Fichte, and attended the lectures of Tholuck at the university of Halle. In 1855 he passed fifth at the first competitive examination for the Indian civil service, and after spending a year in England in the study of law and oriental languages he landed at Calcutta on 26 Sept. 1856. In March 1857 he was appointed an assistant in Hissar, then a district of the north-western provinces, and in the following month was transferred to the Panjáb, where he joined shortly after the outbreak of the mutiny. Owing to this transfer he escaped a massacre of Europeans which took place at Hissar on 29 May. His first station in his new province was Amritsar, and immediately after his arrival there he was employed under the orders of the deputy commissioner in carrying out the measures which were taken to prevent the Jalandhar mutineers from crossing the Eeas river. Shortly afterwards he was appointed personal assistant to the judicial commissioner, in which capacity he compiled 'A Manual of the Criminal Law of the Panjáb' (1860). While thus employed, he was much thrown with Sir John Laird Mair Lawrence (afterwards Baron Lawrence) [q. v.], with whose policy, especially on the Central Asian question, and on British relations with Afghanistan, he was strongly imbued during the remainder of his life. In 1892 he contributed a memoir of Lord Lawrence to Sir William Hunter's 'Rulers of India' series.
In 1859 he joined the secretariat of the government of India as under-secretary in the political department, and served there until 1865, when, at the instance of Sir John Lawrence, then governor-general, in order that he might acquire administrative experience, he took up administrative work in the Panjáb, serving first as a deputy-commissioner and subsequently officiating as com-
