14 



FOEESTATIOX, SAXD HILLS XEBSASKA AXD KAXSAS. 



vicinity of Garden City about 65 per cent. Wliile for short periods 

 the humidity may be low, the vari-ation by months is slight. January 

 and February have the highest relative humidity. 



WIND. 



Both regions are decidedly wind}^, but the Kansas region has a 

 mean w^ind velocity 8 per cent greater than the Nebraska region. 

 While the south winds of summer are fairly desiccatiag, it has been 

 shown at Halsey that the summer winds have very little damaging 

 effect, unless the soil is extremely dry. The early spriag winds from 

 the northw^est are damaging to both field and nursery, because they 

 move the sand and dry out the plants. The winter winds, while not 

 so high, dry out the plants because of the lack of protective snow 

 covering. Trees ^vhich are w^ell established do not suffer as much as 

 those newly planted; faU planting, therefore, is almost certaui to 

 result in heavy losses or complete failure. 



Table 4 show-s the velocity and direction of the wind at Valentine. 

 Nebr., and Dodge, Kans., the stations w-here such records are obtaui- 

 able near the sand-hill planting areas. 



Table 4. — Direction and velocity of uind, by months. 





Valentine, Nebr. 



Dodge City, Kans. 



Month. 



Preyailing 

 direction.! 



Velocity 

 per liour.2 



Preyailing Velocity 

 direction.2 per hour. 2 



January 



NW. 

 NW. 



N. 



N. 



N. 



S. 



S. 



S. 



S. 

 NW. 

 NW. 

 NW. 



Miles. 



9.8 

 10.0 

 11.7 

 13.0 

 12.0 

 11.1 

 10.0 



9.6 

 10.5 

 10.5 

 10.0 



9.8 

 10.7 



NW. 

 NW. 

 NW. 



SE. 



SE. 



SE. 



SE. 



SE. 



SE. 



SE. 

 NW. 

 NW. 



Miles. 

 10.1 



February 



10.9 





12.7 



April 



13.8 



May 



13.2 



June 



12.7 



July 



August 



11.3 

 10.6 



September 



11.2 



October 



11.0 



Noyember 



9.9 



December 



Year. 



10.1 

 11.5 









^ Data from Weather Bureau Bulletin ''Q.'" 



- Data from local offices Weather Bureau, Lincoln and Topeka. 



THE IMPORTANT CLIMATIC FEATURES. 



The three most important features of the climates of both sand- 

 IllLL regions are: (1) The lack of winter precipitation in the form of 

 snow, to form a protective covering for young trees; (2) the great 

 variations in precipitation from month to month, partly counter- 

 balanced by the good w^ater-storing properties of the liills; and (3) 

 the winds of late winter and early spring. While the temperature 

 extremes are not great, the Kansas region doubtless suffers most by 

 reason of its constantly higher temperatures. Especiall}^ in summer 



