52 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



OCEAN METEOROLOGY. 



In general the work of the marine section has progressed along 

 the usual lines. Owing to the effect of the war on ocean shipping 

 the number of vessel reports received during the year has been 

 largely below that of normal times, except from the Pacific Ocean. 

 The examination and charting of reports received from the Atlantic 

 Ocean have continued, and this work has been kept as nearly up to 

 date as feasible. 



It is considered highly desirable that reports received from the 

 Pacific Ocean should be charted in the same manner as those of the 

 Atlantic. Owing to the growth of shipping on the Pacific in recent 

 years it has been possible for the bureau largely to increase the num- 

 ber of vessel reports from that ocean, so that the preparation of a 

 synoptic chart is now believed to be warranted. Plans to accom- 

 plish this are now being formulated. 



The extension of work in the Pacific Ocean has a two fold purpose. 

 Not only is it designed to throw light on coming weather in the 

 United States — weather changes, as is well known, moving from west 

 to east — but it is in line with a concerted and widespread movement 

 in all branches of science to inaugurate a special study of the Pacific, 

 with the object of adding to the world's general knowledge of this 

 vast area. 



During the last hurricane season, extending from July to Novem- 

 ber, many valuable reports were received by wireless from the special 

 service maintained on vessels traversing the West Indian waters and 

 the Gulf of Mexico, enabling the forecasters to determine accurately 

 the position, direction of movement, and rate of progress of the severe 

 storms that reach the mainland of the United States from those 

 regions. 



HYDROLOGIC WORK IN SOUTHERN CALIFORNIA. 



Preliminary action has been taken looking toward the establish- 

 ment of a river district center at Los Angeles, Cal., for the purpose 

 of giving such notice as may be possible of the coming of destructive 

 floods which issue from the mountains of Los Angeles and San Ber- 

 nardino Counties during the prevalence of heavy and continuous 

 rains. Cooperative rainfall observations at 12 points in the moun- 

 tains of Los Angeles County were begun in January, 1916. 



In connection with this subject and closely related thereto, the bu- 

 reau has undertaken, in cooperation with the Forest Service, to carry 

 on a series of rainfall measurements in the Los Angeles National 

 Forest. The chief contracting parties to the cooperation are the 

 board of supervisors of Los Angeles County on the one hand and the 

 Forest Service of the Department of Agriculture on the other hand, 

 the latter representing such other branches of the Federal Govern- 

 ment as are contributing to the work. 



MEASUREMENT OF PRECIPITATION AT HIGH ALTITUDES. 



This work, begun in 1909, in Pacific coast, plateau, and Kock}' 

 Mountain States, has been continued during the year at about 180 

 stations. Intensive measurements of snow depths and densities at 

 the beginning of the melting season have been made in limited regions 



