276 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



available for agricultural and commercial purposes during the 

 spring and summer seasons. The work is still in a formative state, 

 hut t'xixM-iments with the special apparatus devised by Prof. Marvin 

 have, in the main, proved satisfactory; and if funds can be provided 

 for the purchase and installation of a supply of Marvin snow gauges 

 and apparatus sufiicient for all the stations, it is thought that the 

 work can be placed on a permanent basis, and that acceptable fore- 

 casts of water supply can be made each spring over the various 

 watersheds. Opinion regarding this subject is strengthened by an 

 inspection of the results of the special snow surveys in the water- 

 shod of Maple Creek, Utah. The forecast based on the survey and 

 measurements made in the spring of 1911 was of much value to the 

 water users, and a second survey and measurements made in the 

 spring of the present year promises equally valuable results. 



FORESTS, CLIMATE, AND STREAM FLOW. 



The work of the forest experiment station at Wagon Wheel Gap, 

 in the Rio Grande National Forest, Colo., has made satisfactory 

 progress. It will be remembered that this station is maintained 

 jointly by the Weather Bureau and the Forest Service for the pur- 

 pose of studying the effect of forests upon stream flow and climate. 

 There had been some fears that the precipitation at such great eleva- 

 tions (9,200 to 11,000 feet above sea level) and in a supposedly semi- 

 arid region would not be sufficiently heavy to afford a basis for 

 legitimate comparison with data obtained from the more humid 

 regions of the East ; but now that complete data for nearly two years 

 have been obtained, it appears that these fears were more or less 

 unfounded. The total precipitation for 1911 at the principal station 

 of observation was 23.80 inches; over watershed A, 26.88 inches; 

 over watershed B, 27.33 inches; and at the summit or head of both 

 watersheds, 28.56 inches. These data compare favorably with those 

 from other portions of the country and indicate that the final results 

 will permit of more general application than at first supposed. 



The cooperative stations in the Coconino National Forest in 

 Arizona and in the Fremont National Forest in Colorado were also 

 continued during the year, and limited equipment was provided for 

 additional stations in the Kaniksu National Forest in Idaho, the 

 Manti National Forest in Utah, the Cloquet National Forest in Min- 

 nesota, and the Plumas National Forest in California. Data from 

 these stations will be available for study in connection with the more 

 elaborate and complete data from the station at Wagon Wheel Gap. 



DIVISION OF OBSERVATIONS AND REPORTS. 



This division supervises the observational work of the bureau and 

 the preparation of maps for the forecaster. It has charge of the dis- 

 semination of forecasts and storm warnings both on the land and on 

 the ocean, and of frost warnings for the farming, trucking, fruit, and 

 cranberry interests. It has supervisory control of station and com- 

 mercial maps and of the placing of glass maps, bulletin boards, and 

 kiosks. It also has full charge of the marine meteorological work of 

 the bureau and of the Hydrographic Office, comprising the collect- 

 ing of all observational reports and the issuing of ocean meteorolog- 

 ical charts based on those reports, the radiotelegraphic service used 

 for transmitting observations, the dissemination of forecasts to and 



