Background
James Pollard Espy was born May 9, 1785, in Westmorland County, Pennsylvania, United States, one of seven children of Josiah Espy and Margaret Pollard.
Transylvania Universityб 300 N Broadway, Lexington, KY 40508, United States
Espy had an ardent desire for knowledge, and was educated at Transylvania University in Lexington, Kentucky.
Illustration from the book The Philosophy of Storms.
James Pollard Espy was born May 9, 1785, in Westmorland County, Pennsylvania, United States, one of seven children of Josiah Espy and Margaret Pollard.
Espy had an ardent desire for knowledge, and was educated at Transylvania University in Lexington, Kentucky.
Espy taught school before embarking upon a full-time career as a meteorologist in the mid-1830s. He did his earliest known work in the field in 1825 while teaching at the Franklin Institute in Philadelphia, his interest stemming from the writings of Dalton and Daniell.
The most common kind of meteorological activity in the antebellum United States was the gathering of observations. From these observations, physical explanations were sometimes deduced or the data were analyzed mathematically in some fashion. From such roots arose movements to develop networks of observers and regular systems for processing the resulting data. Espy participated in this tradition in the founding of a system of meteorological observations in Pennsylvania in 1836 and in his labors (c. 1840-1852) to erect a national system of volunteer weather observers which was supplanted by Joseph Henry’s telegraph-linked corps of observers.
Espy’s most notable experimental work centered on heat effects. He devised an instrument, the “nephelescope,” to simulate, as it were, the behavior of clouds and, particularly, to measure the dry and moist adiabatic cooling rates. While the resulting data varied from the correct values, Espy displayed great physical insight in deducing the role of latent heat in cloud formation and rainfall.
As the concept of the saturated adiabatic expansion of rising air currents is basic to meteorology, Espy clearly merits recognition as an important pioneer. Lacking any sophisticated mathematical apparatus or knowledge of modern thermodynamics and other factors involved in cloud dynamics, Espy’s work did not lead directly to the work of Kelvin and others from which the modern theory stems.
It is possible, however, that his enthusiastic proselytizing for his views helped pave the way for the acceptance of the later work. In 1840 Espy addressed the Glasgow meeting of the British Association for the Advancement of Science. An account of his theories sent to the French Academy was favorably reviewed in the Competes rends in 1841 by a committee whose members were D. F. J. Arago, C. G. M. Pouillet, and J. Babinet. Espy lectured widely in the United States, undoubtedly deserving credit for stirring up popular interest and support for meteorology. He also served as a meteorologist with the U.S. War Department and the U.S. Navy until 1852, when he continued his work at the Smithsonian Institution, Washington, D.C.
While on a visit to Cincinnati, Ohio, Professor Espy was stricken with paralysis on January 17, 1860, and died at the residence of his nephew, John Westcott, on January 24, 1860. He was buried in the cemetery at Harrisburg, Pennsylvania, by the side of his wife who had passed on ten years earlier.
Espy was a member of the American Philosophical Society.
Espy was contentious and not always receptive to criticism. Time would prove W. C. Redfield, with whom Espy was involved in a controversy, correct on the motion of storms; from his results Espy deduced spectacular conclusions, some unconvincing or apparently refutable. Because of his aprofessional behavior the emerging community of professional scientists was inclined to overlook his real contributions, which have been rediscovered periodically by historically inclined meteorologists.
In 1812 Espy married Miss Margaret Pollard and took her last name as his middle name.