THE WINDBREAK AS A FARM ASSET. 7 



hot, dry winds, often of high velocity, are of frequent occurrence 

 during the summer months, and in Montana and the Dakotas, where 

 the warm west winds of the winter and early spring, known as 

 " chinooks," do great damage to winter wheat and orchards. 



EFFECT ON TEMPERATURE. 



The farmer who has cultivated crops on a hot summer day need 

 hardly be told that the warmest part of his field is the portion\vhich 

 is sheltered from the wind. In the lee of the windbreak there is not 

 only no breeze to cool the body and reduce what is known as the 



FIG. 4. The branches of ash are small and short, and the tree does little damage by 



shading crops. 



" sensible temperature," but the actual temperature of the air is 

 raised. Tests with a thermometer have shown that the area which 

 is protected by a windbreak may be several degrees warmer during 

 the day and several degrees cooler during the night than adjacent 

 areas not protected. 



Such crops as corn are benefited very greatly by warm, sultry 

 days. The windbreak helps to create these conditions and offsets to 

 some extent the effect of cold, cloudy weather. The cooling effect 

 at night is of course unfavorable to growth then; but the night is a 

 period of comparative rest, so that the nocturnal cooling off is far 



