OLMSTED, DENISON (1791–1859), American man of science, was born at East Hartford, Connecticut, U.S.A., on the 18th of June 1791, and in 1813 graduated at Yale, where he acted as college tutor from 1815 to 1817. In the latter year he was appointed to the chair of chemistry, mineralogy and geology in the university of North Carolina. This chair he exchanged for that of mathematics and physics at Yale in 1825; in 1836, when this professorship was divided, he retained that of astronomy and natural philosophy. He died at New Haven, Connecticut, on the 13th of May 1859.
His first publication (1824–1825) was the Report of his geological survey of the state of North Carolina. It was followed by various text-books on natural philosophy and astronomy, but he is chiefly known to the scientific world for his observations on hail (1830), on meteors and on the aurora borealis (see Smithsonian Contributions, vol. viii.).