EVAPORATION I I I 



of Stations present puzzling problems, which may be cleared 

 up with the accession of more data. 



An attempt may now be made to relate the evaporation 

 data here given to the regions of forest centers as given on 

 Transeau's charts. The northeastern conifer forest extends 

 from the southern end of Lake Michigan to Nova Scotia, 

 roughly occupying the valley of the Great Lakes and the 

 St. Lawrence river. In our series, this region is represented 

 by Chicago, Grand Rapids, Burlington, and Orono, four 

 stations which agree fairly well in their average weekly 

 evaporation rates. If we determine the average of these 

 four rates, namely 95, 78, 1 1 1, and 84, we obtain 93 as the 

 average weekly evaporation rate for the entire region of the 

 northeastern conifers. 



The deciduous forest center occupies a region south 

 of the conifer center, reaching from St. Louis to New York 

 City, and extending westward, southward and northward 

 from this line. None of our stations are well located for 

 a study of the conditions obtaining in this center, but four 

 of them are situated near its border, these being St. Louis 

 (137), New York City (49), Newark (84), and Raleigh 

 (157). The average of the rates for these four stations is 

 107, which perhaps approaches the average evaporation rate 

 for the deciduous forest center. 



The desert center of the Southwest is well represented 

 by Mecca (325) , Tucson (265) , and Salt Lake City (219) , 

 which give an average rate for this region of 266. 



The only station in the southeastern conifer center is 

 Gainesville, with an evaporation rate for the season of 141. 

 Much stress must not be laid on this single record. Likewise 

 in the prairie center we have but one well placed station. 

 Lincoln, with a rate of iii. Austin seems to exhibit an 

 evaporation rate between that of the desert center and that 

 of the deciduous forest, and its location would seem to 

 support this view. 



