of tfy 



been rendered less hardy. With good care, these 

 plants are heavy producers, but, to have from 

 them a premium harvest each year, they need 

 the genial clime, the stimulating shelter, and 

 the constant protection which only forests can 

 supply. Closely allied to changes of tempera- 

 ture is the movement of the air. In the sea 

 every peninsula is a breakwater: on land every 

 grove is a windbreak. The effect of the violence 

 of high winds on fruited orchards and fields of 

 golden grain may be compared to the beatings 

 of innumerable clubs. Hot waves and cold 

 waves come like withering breaths of flame and 

 frost to trees and plants. High winds may be 

 mastered by the forest. The forest will make 

 even the Storm King calm, and it will also 

 soften, temper, and subdue the hottest or the 

 coldest waves that blow. Forests may be placed 

 so as to make every field a harbor. 



The air is an invisible blotter that is con- 

 stantly absorbing moisture. Its capacity to 

 evaporate and absorb increases with rapidity 

 of movement. Roughly, six times as much 

 water is evaporated from a place that is swept 



126 



