SKETCH OF JAMES P. ESPY. 835 



late Prof. A. D. Baclie, he became known as "one of the best 

 classical and mathematical instructors in Philadelphia, which at 

 that day nnmbered Dr. Wylie, Mr. Sanderson, and Mr. Crawford 

 among its teachers. Impressed by the researches and writings of 

 Dalton and of Daniell on meteorology," Prof. Bache continued, in 

 a eulogy before the Regents of the Smithsonian Institution, " Mr. 

 Espy began to observe the phenomena and then to experiment 

 on the facts which form the groundwork of the science. As he 

 observed, experimented, and studied, his enthusiasm grew, and 

 his desire to devote himself exclusively to the increase and dif- 

 fusion of the science finally became so strong that he determined 

 to give up his school, and to rely for the means of prosecuting his 

 researches upon his slender savings and the success of his lect- 

 ures, probably the most original which have ever been delivered 

 on this subject. His first course was delivered before the Frank- 

 lin Institute of Pennsylvania, of which he had long been an active 

 member, and where he met kindred spirits, ready to discuss the 

 principles or the applications of science, and prepared to extend 

 their views over the whole horizon of physical and mechanical 

 research. As chairman of the Committee on Meteorology, Mr. 

 Espy had a large share in the organization of the complete sys- 

 tem of meteorological observations carried on by the Institute 

 under the auspices and within the limits of the State of Pennsyl- 

 vania." Mrs. Morehead quotes from the account of a friend who 

 visited him in Philadelphia a description of Prof. Espy's method 

 of pursuing his atmospheric calculations, which necessarily had 

 to be carried on out of doors. The high fence inclosing the small 

 yard was of smooth plank, painted white, while the space inclosed 

 was filled with vessels of water and numerous thermometers for 

 determining the dew-point. The white fence, when last seen by 

 the narrator, was so covered with figures and calculations that 

 not a spot remained for another sum or column. Prof. Espy's 

 theory of storms was first developed in successive memoirs in the 

 "Journal of the Franklin Institute," containing discussions of 

 ih.Q changes of temperature, pressure, and moisture of the air, 

 and of the direction and force of the wind, and other phenomena 

 attending remarkable storms in the United States and on the 

 ocean adjacent to the Atlantic and Gulf coast. " Assuming great 

 simplicity," says Prof. Bache, " as it was developed, and founded 

 on the established laws of physics, and upon ingenious and well- 

 directed experiments, this theory drew general attention to itself, 

 especially in the United States. A memoir submitted anonymously 

 to the American Philosophical Society of Philadelphia gained for 

 Mr. Espy the award of the Magellanic premium in the year 1836, 

 after a discussion remarkable for ingenuity and closeness in its 

 progress, and for the almost perfect unanimity of its result." 



