8 



sandbar willow are found growing naturally in the sandhills of 

 Kansas and Nebraska, which is evidence that good conditions of soil 

 moisture exist. The sandhills, therefore, are favorable localities for 

 tree planting. 



CLIMATE. 



The climate of western Kansas is ordinarily classified as subhumid 

 or semiarid. Its chief characteristics are those common throughout 

 the Great Plains. The average annual precipitation is sufficient for 

 paying crops. The distribution, ho.wever, is subject to great fluctua- 

 tions. The summer rainfall comes mostly from local thunderstorms, 

 whose erratic courses may or may not overlap. Consequently one 

 locality often receives enough rain during the season, while another a 

 few miles away suffers from drought. 



There is also a marked tendency to a succession of wet and dry sea- 

 sons over the entire region. This is well illustrated by comparing 

 the records at Dodge City for 1883 and 1884 with those for 1893 and 

 1804. It happens that there is a ten-year period in this case, but 

 observations do not prove any regular periodicity. 



Annual precipitation at Dodge, Kans. 



The wet years of 1883 ancf 1884 were largely responsible for the 

 " boom," which resulted in the rapid settling up of the country be- 

 tween the years 1885 and 1887, while the dry seasons of ten years later 

 caused wholesale depopulation. 



The average precipitation at the principal Weather Bureau sta- 

 tions, with the number of years that the record has been kept, is given 

 in the following table : 



Average annual precipitation. 



While the record at Dodge City is the only one covering a sufficient 

 period to be considered approximately correct, the others are good 



[Cir. 161.] 



