686 forestry Quarterly. 



following formula, in which V is the f. o. b. mill value. per 

 acre (the sum of the f. o. b. mill values of each product multiplied 

 by the average stand) and C is the operating cost per acre, ex- 

 clusive of railroad construction (the product of the stand per 

 acre in board feet and the operating cost per thousand) 



X = (V— C— R) — 1/5V 

 Since V — C=I=:index value per acre 



X = (I-R) -1/5 V 



Then the stumpage value per dollar of gross profit can be ob- 

 tained by dividing the stumpage value per acre by the gross 

 profit per acre, and the stumpage value per unit quantity by each 

 product can be obtained by multiplying the gross profit on that 

 species by the stumpage value per dollar of gross profit. The 

 formula is: 



X 



x=j— ^ (v— c— r) 



Using the same set of conditions as in the previous computa- 

 tions, table 3 shows the application of this modified form of the 

 Forest Service formula. 



It should be mentioned in this connection that another method 

 of distributing the stumpage values as given by the Forest Serv- 

 ice formula between species of different value has already been 

 worked out on the same principle and arriving at the same re- 

 sults, but by a different arithmetical process. However, this 

 method seems preferable to the authors, and is especially appli- 

 cable when the fixed charges have been apportioned by the similar 

 method already described. 



Table 3. — Stumpage value by modified Forest Service formula 

 Construction cost, operator's profit, and stumpage distribution 

 on value basis. 



Stumpage 



.__.(v_c-r) 



1.83 



1-53 



.31 



.31 



1.07 



.08 



