MACLURE, William, geologist, born in Ayr, Scotland, in 1763; died in San Angel, Mexico, 23 March, 1840. He visited New York in 1782, but soon returned to London, where be became a partner in the firm of Miller, Hart and Co., and rapidly acquired a fortune. In 1796 he returned to the United States, and in 1803 he served abroad as one of the commissioners to settle the French spoliation claims of American citizens. While in Europe he became interested in geology, and collected objects in natural history. On his return he undertook the geological survey of the entire country, depending on his private resources and observations, and at a time when geology was not regarded as a science, so that but few sympathized with his motives, he visited nearly every part of the country, and crossed the Alleghanies fifty times. In January, 1809, he presented his " Observations on the Geology of the United States, explanatory of a Geological Map," before the American philosophical society, and so the matter came before the public. He continued his explorations, and in 1817 again discussed this subject before the same society, presenting his map. Its publication, with the description, attracted much attention, and he was styled the "father of American geology." He became a member of the Academy of natural sciences soon after its organization in 1812, and was its president from 1817 till his death. Its library and museum were enriched by his books--nearly 5,000 volumes--and his specimens, making a collection that was unequalled in the United States. His contributions to the society in money aggregated $25,000, and by means of them it was able to complete its edifice on Broad street, Philadelphia. In 1816-'17 he visited the West India islands to study their geology, and he published subsequently an account of twenty visits to those islands. He went to France in 1819, and then to Spain, where he proposed to establish a great agricultural school for the lower classes, in which labor should be combined with moral and intellectual culture. He purchased land near Alicante and erected buildings; but on the overthrow of the revolutionary government the land reverted to the church, from which it had been confiscated. In 1824 he returned to the United States, and, associating with him Thomas Say, Gerald Froost, and other scientists, attempted to carry out a similar plan in New Harmony, Indiana. For several years Mr. Maclure continued his efforts, in hope of bringing the school into operation, but without success. In 1827 he went to Mexico in failing health, and continued to reside there until his death, with occasional visits to the United States. He was president of the American geological society in 1828. Mr. Maclure contributed numerous papers to the "American Journal of Science," and published "Opinions on Various Subjects," devoted mainly to questions of political economy (2 vols., New Harmony, 1837).