146 THE FOREST LANDS OF FINLAND. 
years on poor lands; and timber for saw-mills should be 
from 100 to 140 years of age. In Central Finland, up to 
64°, the growth of trees requires about 20 years more 
under the same conditions. In fine, in the North they do 
not obtain firewood or carpentry wood under the age of 
120 to 180, or timber for saw-mills before from 180 to 230 
years’ growth. 
