74 



PKINCIPLES OF AMERICAN FORESTRY. 



the cuts, and these are again cut when of suitable size. 

 What has been said in regard to the season and manner 

 of cutting in the previous paragraphs is practically tiue 

 here. This process is mostly used in the case of Willows 

 and Poplars to obtain material for basket-work, small 

 poles, fuel, etc. 



Time of Rotation is a term used to indicate the age to 

 which trees are grown. The length of this time ^\il\ 

 depend on the species and on the conditions. For some 



Fig. 17.- 



-Showing proper way of cutting Pollards and growth after 

 same has been cut. 



species not less than eighty years should be allowed for 

 full maturity, while still others may be successfully worked 

 on a thirty-year rotation period. It is not used in the 

 same sense as in ordinary agricultural operations, where 

 it signifies frequent changes of the crop for several years 

 with a vie^^■ to getting the most out of the soil. Since 

 trees do not impoverish the soil, but improve it, there is no 



