86 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



bocoiniiig more and more appruciuteel, ami Llierel'ore is playiiif^ a 

 useful role in the development of meteoroloji^y. is shown by the neces- 

 sity of increasinjx the edition i)ublished from 1.525 for the last num- 

 ber in fiscal year 1919 to 1,750 for the correspondinii" issue a year 

 later. Even with 1,750 copies published, the supply oi' the last three 

 issues held for sale has been exhausted. A lar<re part of the increases 

 in demand came through paid subscriptions, which nearly doubled. 



In addition to the usual editorial work, the results of investigations 

 undertaken mainly in the interests of improved general and local 

 forecasting, especially of winds at flying levels, were prosecuted and 

 published. Specifically, these were — clouds and their significance, 

 eifect of winds and other weather conditions on the flight of air- 

 planes and balloons, sleet and ice storms (glaze), preliminary steps 

 in the making of free-air pressure, and wind charts. Reprints of the 

 articles on w'cather and aeronautics were distributed to all aviators 

 of the Army and Navy. Durin.g four months daily open-air instruc- 

 tion and lectures on clouds and their signilicance to classes of naval 

 meteorological officers were given. 



LIBRARY. 



During the fiscal year 1,050 books and pamphlets were added to 

 the librar}^, the strength of which is now over 39,000. Political 

 changes brought about by the war have greatly complicated the work 

 of libraries in Avhich, jfs in the case of the Weather Bureau library, 

 a large part of the collection is classified and shelved according to 

 geographical divisions. Reclassification of many books to take ac- 

 count of recent changes oi this character is in progress. The same 

 cause has made necessary an extensive revision of the foreign mail- 

 ing lists of Weather Bureau publications, and this has been carried 

 out by the librarian. A marked growth of interest in meteorology 

 that has followed the war is indicated by the large number of re- 

 quests which the library now receives from all parts of the United 

 States and elsewdiere for information and the loan of books. 



INVESTIGATIONS IN SEISMOLOGY. 



The important work of collecting and publishing earthquake data, 

 begun Def ember 1, 1914, has been continued during the year. 



During the calendar year 1919, 86 separate earthquakes, strong 

 enough to be felt, were reported from different parts of the con- 

 tinental United States. The great majority of these produced no 

 damage Avhatever, and none produced any important damage. No 

 important earthquakes occurred in our outlying possessions. 



VOLCANOLOGY. 



The work in volcanological observations is conducted at the crater 

 ■ of the volcano Kilauea, Hawaiian Islands, and was taken over by the 

 Weather Bureau on the loth of February, 1919, under an appropria- 

 tion by Congress of $10,000, which has been continued yearly smce 

 that time. The funds available have been just adequate to carry on 

 the routine activities of observational Avork organized a number of 

 years ago under the direction of Dr. James A. Jaggar, jr., origi- 



