n6 THE POPULAR SCIENCE MONTHLY. 



veloped new paths of activity for this service, may be mentioned the 

 study of local thunder-storms and tornadoes, which were respectively 

 assigned to Professor Hazen and Lieutenant Finley so far as a collec- 

 tion of general statistics is concerned ; and to Professor Mendenhall, 

 so far as concerns the electrical phenomena proper. The study of 

 atmospheric electricity was especially authorized in 1884, by an order 

 of the Secretary of War, transmitting the resolutions of the Interna- 

 tional Electrical Conference held in Paris the preceding year. After 

 full consultations with numerous electricians throughout the country, 

 General Hazen decided that a daily map of electric potential show- 

 ing lines of equi-potential similar to the iso-barometric lines, offered 

 hopeful prospect of eventually leading to a method of predicting 

 the formation and motion of thunder-storms and tornadoes. But 

 the methods of observation, and the apparatus, needed first to be de- 

 termined upon, after careful experimental work. This whole matter 

 was, therefore, in 1885, committed to the hands of Professor Men- 

 denhall. 



Perhaps the most important item in internal administration, so far 

 as it affects the permanent scientific value of the office-work, was the 

 effort heartily furthered by General Hazen to improve the accuracy 

 and international comparability of our instrumental equipment. The 

 standards of the International Bureau of Weights and Measures were 

 recognized by him as being the proper legal standards for this office, 

 and every effort made to determine the corrections needed to reduce 

 the past as well as the current meteorological observations of the Sig- 

 nal-Service to agree therewith. 



Perhaps the generous breadth of General Hazen's views, the absence 

 of injurious jealousies, and his confidence in the principle that the 

 Weather Bureau would be strengthened by the widest diffusion of an 

 intelligent appreciation of meteorology, are in nothing more clearly 

 shown than in the earnestness with which he stimulated the formation 

 of state weather services, and encouraged the study of meteorology in 

 every school and college. He was painfully impressed by the disas- 

 trous influence upon individuals and business of the wide-spread and 

 utterly absurd predictions of the storms and weather of March 9, 1884, 

 which were distributed broadcast throughout the country, and ema- 

 nated from Mr. Vennor. He saw clearly that all this harm could only 

 be prevented by increasing the intelligence of the people in scientific 

 matters, and heartily indorsed every effort to diffuse a more correct 

 idea as to what constituted legitimate meteorology. 



Although his duties demanded the maintenance of a great central 

 office at Washington, yet General Hazen realized that centralization 

 could easily be carried too far in scientific matters, and would thus 

 react injuriously upon the work of his office. He was desirous of 

 rapid progress in all directions, and, to secure this, welcomed every 

 prospect of co-operation with other institutions as well as with individ- 



