EEPORT OF THE SECRETARY. 187 



charts in the parks or on the streets of large cities. These kiosks, as 

 they are called, have been installed in 37 of the larger cities of the 

 country and have proved an excellent means of acquainting the aver- 

 age citizen with the way in which the Weather Bureau obtains and 

 distributes its weather information. 



EVAPORATION STUDIES. 



The formation of the Salton Sea in the desert of southern Cali- 

 fornia by overflow flood waters from the Colorado River afforded an 

 exceptionally favorable opportunity for the study of the general 

 problem of evaporation. A preliminary campaign was begun at 

 Reno, Nev,, in 1907, and an elaborate investigation followed during 

 1908 and 1909 at the Salton Sea, with the primary object of deter- 

 mining an evaporation formula that would be of general application. 

 The results obtained were somewhat negative, indicating that, owing 

 to differing meteorological conditions, the law of evaporation must 

 be established independently for each separate locality. A great 

 mass of valuable data was secured, however, and the work can not by 

 any means be considered a failure. 



FOREST AND RAINFALL INVESTIGATIONS. 



The problem of the conservation of the natural resources of the 

 country has in recent years become one of the great issues of the day. 

 As might naturally have been expected, honest differences of opinion 

 have arisen in connection with various phases of the question. Prob- 

 ably none has been the subject of more vigorous discussion than that 

 relating to the effect of forestation or deforestation upon water sup- 

 ply and water control, particularly with reference to floods. As the 

 data at hand were apparently not conclusive, the Weather Bureau 

 and the Bureau of Forestry of the Department of Agriculture com- 

 bined forces in 1910 for a thorough investigation and study of the 

 entire problem, in the hope of arriving at results that would be 

 accepted as authoritative; and two small and similar watersheds in 

 the Rio Grande National Forest in southwestern Colorado were 

 selected as offering suitable conditions for prosecuting the necessary 

 investigations. An elaborate equipment was provided, and obser- 

 vations are now being taken daily over both watersheds. In 8 or 10 

 years it is proposed to deforest one of the watersheds and then to 

 continue the observations over both for another period of 8 or 10 

 years. At the end of the second period the results are to be promul- 

 gated with such conclusions as are warranted by the facts. Foreign 

 countries have expressed great interest in the experiment, and the 

 final results and conclusions will doubtless prove of much value. 



