Periodical Literature. 545 



The advantage of the formula is that conditions as they actually 

 are at present enter into its make-up. Theoretically, it is true 

 that a management class is made up of a number of single stands 

 and the whole must be equal to the sum of its parts, but while 

 this is mathematically true, it is not so economically ; and this is 

 illustrated in actual forest management. A single stand does not 

 permit of an annual management, while a management class in 

 age classes does, the latter exhibits a stock capital, which is un- 

 known in the former case. Other managerial differences are 

 pointed out. Heyer's attitude that the stock must be figured at 

 cost value is combated, since for most older stands it would be^ 

 impossible to state its actual cost value; moreover, if a stand had 

 an actual stock value of $3,000, nobody will place its value at 

 $6,000, even if that were its cost of production, or at $1,500, if 

 by good chance it had only cost that sum to produce it. 



The formula, which is really derived from one of Gustav 

 Heyer's, is applicable to normal as well as actual conditions, and 

 it forces, indeed, investigation of these conditions in a direction 

 which corresponds to the needs of practical forest management. 

 It gives expression to the most important problems of the soil- 

 rent theory, namely to secure or demonstrate a proper relation be- 

 tween yield and capital involved. The latter is the actual not 

 potential capital. The soil capital is as a rule relatively so small 

 that it has little influence on the result. The stock is the im- 

 portant part, but in most German administrations no account of 

 it is given ; instead, age class distribution gives an approximate 

 idea of its make-up, which is, to be sure, also desirable. For 

 calculating the stock no generally applicable rules can be given; 

 it will vary according to silvicultural practices, natural regen- 

 eration or clear cutting, and according to other conditions. Site 

 and age classification are, of course, unavoidable in these calcu- 

 lations. "In spite of the difficulties of estimating the stock values, 

 it is nevertheless an important requirement of a good working 

 plan : it is better to have a statement which is faulty than none at 

 all." 



In the end, such valuations are practical necessities not only for 

 good management but for taxation, etc. 



Die Formel, etc. Allgemeine Zeitschrift fur Forst-u. Jagdwesen. April, 

 1912. Pp. 109- 1 19. 



