Espy, James Pollard

Espy, James Pollard

(ĕs`pē), 1785–1860, American meteorologist. He developed a convection theory of storms, explaining it in 1836 before the American Philosophical Society and in 1840 before French and British scientific societies; his Philosophy of Storms was published in 1841. He became meteorologist to the War (1842) and Navy (1848) departments and developed the use of the telegraph in assembling weather observation data by which he studied the progress of storms and laid the basis for scientific weather forecasting.

Espy, James Pollard


Born May 9, 1785, in Washington County, Penn.; died Jan. 24, 1860, in Cincinnati, Ohio. American meteorologist.

Beginning in 1817, Espy worked at the Franklin Institute. In 1843 he became director of the Weather Bureau of the US War Department, where he compiled the first weather maps in the United States. Espy developed the theory of atmospheric convection with allowance for the heat released by the condensation of vapor in clouds. He also proposed the “centripetal” theory of cyclones, an important step in the development of the theory of cyclone formation.


The Philosophy of Storms. Boston, 1841.


Khrgian, A. Kh. Ocherki razvitiia meteorologii. Leningrad, 1948.
Shaw, N. Manual of Meteorology, vol. 1. Cambridge, 1926. Page 136.