Page:Popular Science Monthly Volume 37.djvu/711

Rh and inaugurated systematic observations of atmospheric electricity. One of the results of his work was proof that rain precipitation 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 established the systematic gathering of data regarding earthquakes from stations scattered throughout the United States. Immediately after the earthquake of August 31, 1886, he visited Charleston, 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 responsibilities 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 member 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 President to fill the superintendency of the United States Coast and Geodetic Survey, one of the most important scientific appointments 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 prosecution. 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