THE FINANCIAL VALINE OF THE YIELD. 237 



The normal annual yield of overwood must also be equal to 

 the annual increment laid on by all the overwood during one 

 year, or 



7= 2-0 X 200+ (15 - 2) X 130+ (30 - 15) X 80+ (50 - 30) X 40, 

 7 = 4,090 cubic feet. 



As ah'eady indicated, this calculation is only of theoretical 

 value. 



2. The Financial Value of the Xormal Yield. 



The financial value of the normal yield is that, which secures 

 interest on all capital invested in a forest exactly at the rate of 

 the general per cent, j), at which money can be obtained for 

 forestry, or at which money taken out of the forest can be in- 

 vested with equal security as in forestry. The financial yield 

 is realised, as long as a financial equilibrium on the above lines 

 exists in the forest, that is to say, when the forest per cent, is 

 equal to the general per cent. p. This occurs under a rotation 

 equal to that, for which the expectation value of the soil reaches 

 its maximum. 



Example : — 



Taking the data in the table at page 120, and a rotation of 

 80 years — 



Soil expectation value for 80 units of area = shlgs. 



80 X 404 = 32,320 



Financial value of normal "rowing stock . = 91,360 



Total = 123,680 



Financial Normal Y = 123,680 X "025 = 3,092 shillings; 

 or 38*65 shillings for each acre of forest. 



