CROKER, THOMAS CROFTON (1798-1854), Irish antiquary and humorist, was born in Cork on the 15th of January 1798. He was apprenticed to a merchant, but in 1819, through the interest of John Wilson Croker, who was, however, no relation of his, he became a clerk in the Admiralty. Moore was indebted to him in the production of his _Irish Melodies_ for "many curious fragments of ancient poetry." In 1825 he produced his most popular book, the _Fairy Legends and Traditions of the South of Ireland_, which he followed up by the publication of his _Legends of the Lakes_ (1829), his _Adventures of Barney Mahoney_ (1852), and an edition of the _Popular Songs of Ireland_ (1839). In 1827 he was made a member of the Irish Academy; in 1839 and 1840 he helped to found the Camden and Percy Societies, and in 1843 the British Archaeological Association. He wrote _Narratives Illustrative of the Contests in Ireland in 1641 and 1688_ (1841), for the Camden Society, _Historical Songs of Ireland_, &c. (1841), for the Percy Society, and several other works. He was also a member of the Hakluyt and the Antiquarian Society. He died in London on the 8th of August 1854.
CROLL, JAMES (1821-1890), Scottish man of science, was born of a peasant family at Little Whitefield, in the parish of Cargill, in Perthshire, on the 2nd of January 1821. He was regarded as an unpromising boy, but a trifling circumstance aroused a passion for reading, and he made great progress in self-education. He was apprenticed to a wheelwright at Collace in Perthshire, but being debarred by ill-health from manual labour, he became successively a shop-keeper and an insurance agent. In 1859 he was made keeper of the Andersonian Museum in Glasgow, a humble appointment, which, however, gave him congenial occupation. In 1857, being deeply impressed by the metaphysics of Jonathan Edwards, he had published an anonymous volume entitled _The Philosophy of Theism_; but his connexion with the Museum induced him to take up physical science, and from 1861 onwards he studied with such perseverance that he was enabled to contribute papers to the _Philosophical Magazine_ and other journals. For that magazine in 1864 he wrote his celebrated essay "On the Physical Cause of the Changes of Climate during Geological Epochs." This led to his receiving an appointment on the Scottish Geological Survey in 1867, and for thirteen years he took charge of the Edinburgh Office. In 1875 he summed up his researches upon the ancient condition of the earth in his _Climate and Time, in their Geological Relations_, in which he contends that terrestrial revolutions are due in a measure to cosmical causes. This theory excited warm controversy. Croll's replies to his opponents are collected in his _Climate and Cosmology_ (1885). He had been compelled by ill-health to withdraw from the public service in 1880; yet, working under the greatest difficulties, and harassed by the inadequacy of his retiring pension, he managed to produce _Stellar Evolution_, discussing, among other things, the age of the sun, in 1889; and _The Philosophical Basis of Evolution_, partly a critique of Herbert Spencer's philosophy, in 1890. He died on the 15th of December 1890. The soundness of Croll's astronomical theory regarding the glacial period has since been criticized by E. P. Culverwell in the _Geological Magazine_ for 1895, and by others; and it is now generally abandoned. Nevertheless it must be admitted that his character as a scientific worker under great discouragements was nothing less than heroic. The hon. degree of LL.D. was conferred on him in 1876 by the university of St Andrews; and he was elected F.R.S. in the same year.