THE AUSTRIAN METHOD. 319 



to determine the real final age and the volume at that 

 age for each wood. 



(4) The difference between the real and normal growing 



stock is removed during such period as the owner, or 

 forester, may determine according to the circumstances 

 of each case. 



(5) The general formula for calculating the yield, if the 



deficiency or surplus of growing stock is to be removed 

 in the course of a years, runs as follows : 



, v TJ IT , real Gr. Stk. norm. Gr. Stk. 



Annual Yield = real lncrement+ 



a 



Y=I r + G *~ G *. 



b. Merits of the Method. 



The method was the first which based the calculation of the 

 yield upon a knowledge of the increment and the growing 

 stock. It has the advantages over the previously-described 

 methods that : 



(1) It teaches the proportion between the real and normal 



growing stock, and enables the owner to remove any 

 surplus or deficiency at his pleasure. 



(2) It assures to the owner the utilization of the full real 



increment, whenever the normal growing stock is 

 present. 



(3) It distinguishes in the yield between increment and 



growing stock ; in other words, between the removal 

 of genuine annual increment and that of surplus 

 capital. 



On the other hand, the method, as above described, has 

 serious drawbacks : 



(1) The calculation of the real and normal growing stock, 

 based upon the final mean annual increment, is not 

 correct and not even safe. As, however, both are 

 calculated in the same manner, and one is deducted 



