SKETCH OF THOMAS CORWIN MENDENHALL. 693 



and inaugurated systematic observations of atmospheric electrici- 

 ty. One of the results of his work was proof that rain precipi- 

 tation is the cause rather than the -effect of electrical discharges 

 in the atmosphere. He concurrently investigated the methods 

 for ascertaining ground temperatures, inventing improved forms 

 of apparatus. Pursuing a line of inquiry begun in Japan, he es- 

 tablished the systematic gathering of data regarding earthquakes 

 from stations scattered throughout the United States. Immedi- 

 ately after the earthquake of August 31, 1886, he visited Charles- 

 ton, and made a report upon the agitation with a co-seismic chart 

 showing the disturbed area. It seems probable that, before many 

 years elapse, the phenomena of earthquakes will have sufficiently 

 yielded their secrets to enable predictions of their occurrence to 

 be made, following up and perfecting the methods by which the 

 Weather Bureau now issues its forecasts. In this branch of 

 science, as important as it is difficult, Prof. Mendenhall has done 

 invaluable work as a pioneer. After two years' service of the 

 Government, he resigned, to accept the presidency of the Rose 

 Polytechnic Institute in Terre Haute, Indiana. His new respon- 

 sibilities were discharged with marked success; he brought to 

 them rare address, tact, and executive ability. The Institute, 

 young as it was, soon had an assured place among the leading 

 technical schools of the country. That it supplies an educational 

 need in the flourishing city in which generosity has placed it 

 came out plainly at its commencement exercises last year. On 

 that occasion Prof. Mendenhall was able to say that every mem- 

 ber of the graduating class had secured an engagement and was 

 fairly launched upon his life-work. 



In July, 1880, Prof. Mendenhall was nominated by the Presi- 

 dent to fill the superintendency of the United States Coast and 

 Geodetic Survey, one of the most important scientific appoint- 

 ments in the country, and which has been held by men of the 

 stamp of Alexander Dallas Bache, Benjamin Peirce, and Julius E. 

 Hilgard. Prof. Mendenhall succeeds to their fame, but also to 

 administrative duties which have grown more onerous with every 

 year of the survey's history. He has nevertheless an opportunity 

 for scientific work which his energetic and organizing mind is not 

 likely to leave unimproved. His interest in the gravitation work 

 which the survey has carried on for several years has led to the 

 formation of new plans for its more rapid and vigorous prosecu- 

 tion. For some time past the survey has been engaged in the 

 study of terrestrial magnetism ; its researches in this direction are 

 being actively pressed forward, one aim being to locate the north 

 magnetic pole with precision. In geodesy the survey is steadily 

 advancing the great transcontinental system of triangulation, and 

 some new contributions of importance toward our knowledge of 



