REQUIREMENTS FOR THE BEST SERVICE. 13 



need of fuel might be much inconvenienced to find no 

 trees on his woodlot big enough for cord wood, and it 

 would not help him to know that twenty years later he 

 would have an oversupply. In the same way a larger 

 forest may yield only a very irregular and unsatisfac- 

 tory product if at one time there are too many ripe 

 trees and at another too few. For example, if 100 

 acres become fit to cut this year, and 200 next year, 

 and after that none at all until 500 acres become ripe 

 fifteen years later, it is easy to see that the yield would 

 come at very irregu- 

 lar and perhaps very 

 inconvenient times. 

 But a forest of 

 10,000 acres, com- 

 posed of 100 even- 

 aged groups of trees 

 of every age from 

 1 to 100 vears, each 



FIG. 5. Diagram of a forest with one hundred 

 even-aged compartments. 



group 100 acres in 

 extent (see fig. 5), 

 would plainly be able to furnish every year 100 acres 

 of 100-year-old trees ready for the ax. In such a for- 

 est the right proportion of young trees would always 

 be coming on. 



The fourth requirement is growing space enough for 

 every tree, so that the forest as a whole (see fig. 7) 

 may not only produce wood as fast as possible, but 

 the most valuable sort of wood as well. If the trees 

 stand too far apart, their trunks will be short and 

 thickly covered with branches, the lumber cut from 



