FOREST MANAGEMENT. 337 



the annual possibility of the forest is ascertained. The method perpetuates 

 the original composition of the forest, calling it normal because natural. 



An illustration might be obtained from the data contained in bulletin 

 No. 32, Bureau of Forestry, prepared by F. E. Olmsted: 



Diameter of mature trees, 20 inches and over. 



Number of mature trees, per acre, 4.94. 



Number of immature trees, having 15 inches to 19 inches diameter, per 

 acre, 4.99. 



Number of years required by a 15-inch tree to mature, 34. 



The annual possibility, after Brandis, in this case amounts to 



4-94 



= o. 145 



34 

 mature trees per acre, or 145 mature trees for every 1,000 acres. 



After bulletin No. 32, the volume of the trees having 20 inches over at 

 breast height is 4561 feet b. m. 



The possibility in lumber is, consequently, 



45 61 



34 

 feet b. m. per acre per annum. 



1 34 



Aetl)ods Regulating tl)e Investments and tl)e Returns 



The methods to be described are: 



Judeich Method. 



Raess Method. 



Schenck Method. 



Judeich, Raess and Schenck advocate conservatism only when con- 

 servative forestry pays better than destructive forestry. 



A " sustained yield '" is considered only where it guarantees better 

 financial results than an irregular yield. 



No two forests are alike. The financial development of any forest 

 offers a problem of its own; on the basis of a difference -listing in the 

 resources of the forest; the accessibility of the forest; the availability of 

 manual labor; the climate; the dangers threatening the forest, etc. . 



