1911 Encyclopædia Britannica/Oldham, Thomas
OLDHAM, JOHN (1816–1878) British geologist, was born in Dublin on the 4th of May 1816. He was educated there at Trinity College, graduating B.A. in 1836, and afterwards studied engineering in Edinburgh, where he gained a good knowledge of geology and mineralogy under Jameson. On his return to Ireland in 1839 he became chief assistant to Captain (afterwards Major General) Portlock, who conducted the geological department of the Ordnance Survey, and he rendered much help in the field and office in the preparation of Report of the Geology of Londonderry, &c. (1843). Subsequently he served under Captain (afterwards Sir Henry) James, the first local director of the Geological Survey of Ireland, whom he succeeded in 1846. Meanwhile in 1845 he was appointed professor of Geology in the university of Dublin. In 1848 he was elected F.R.S. In 1849 he discovered in the Cambrian rocks of Bray Head the problematical fossil named Oldhamia. In 1850 he was selected to take charge of the Geological Survey of India, which he organized, and in due course he established the Memoirs, the Paleontologia Indica and the Records, to which he contributed many important articles. In 1864 he published an elaborate report On the Coal Reserves of India. He retired in 1876, and died at Rugby on the 17th of July 1878.