Rate of Interest 257 



ures, taken from the normal yield tables of Schwappach, may 

 help to answer this question. The following premises should be 

 kept in mind : 



1. The forest is normal, both as to age classes and conditions 

 of stands; it is not the best, but the average of fully stocked 

 forest. 



2. The prices are actual current prices for Central Europe, and 

 are stumpage prices. 



3. The value of the growing stock, yields and thinnings are 

 the actual sale value, so that young stands, not yet marketable, 

 are ignored entirely. 



4. The value of land is assumed by the writer as follows, for 

 site II : 



for oak, $80 per acre ; 

 beech, $60 " " 

 spruce, $50 " " 

 pine, $40 " " 



which is believed to represent fairly the present day conditions 

 and values in Germany. 



5. The expenses for: Reproduction (Planting), c, $10 per acre; 

 Administration, protection, taxes, etc., e, $1 per acre. 



6. The value of the normal growing stock for any rotation is 

 the sum of the values of the main stands (Gn), as given in the 

 tables for each decade up to and inclusive of the year of rotation 

 multiplied by 10.^ Thus, for the 80-year rootation in spruce, the 

 values of the main stands from 30 (the youngest salable material) 

 to 80 years are added and multiplied by 10. 



The following tables give some of the results : 



Spruce, Site II, after Schwappach 



Yearly Cut Net Income 



'To make this mathematically correct, the last number of the series 

 should be divided by 2. — Ed. 



