DETERMINATION OF THE PROFIT. 159 



The receipts consist of: 



(a) All items of income realized between the formation of 



the wood and the year m, with accumulated interest 

 to the year m : 



T a xl'op m ~ a +...T m . 



(b) All items of income to he realized between the year m 



and the end of the present rotation r, discounted to 

 the year m : 



T n xl'op r - n +. . . 



(c) All items of income to be realized during subsequent 

 rotations, amounting to : 



T a xl'op r ~ a +. . . 



(l'op r -l)xl'op r -< 

 The costs are : 



(a) Past costs with compound interest to the year m : 



S c xl'op m +E (l'op m l) + cxl'op m . 



(b) Costs to be incurred from the year m to the end of the 



rotation : 



E(l'op r - m -l) 



(c) Costs to be incurred during future rotations : 



E cxl'op r 



l'op r ~ m (l'op r -l) X l'op r - m ' 



By deducting all costs from the receipts, the profit is 

 obtained and represented by the following formula : 



Profit P = 



Y r + T a x l'op r ~ n + . . . + T q xl'op r - q -E (lop r - m -l] T 



+ ."r-m V 1 ') 



Y r +T a xl'of - + ... -cxl'of 



~ 



\ 



E ) - (IL) 



