452 ESTIMATION OF INCREMENT 



Thus, to take a previous example, if, 10 years ago, a crop 

 contained 1500 cubic feet of saleable timber worth 8d. a 

 foot, and is now estimated to contain 2200 cubic feet of sale- 

 able timber worth rod. a foot : 



Then the percentage of increment in money value 



will have been 



200 10-8 



X 



10 18 



= ??? x = 2-22 per cent. 

 10 9 



Now, the percentage increment in contents has already been 

 shown to have been 3-75 per cent. 



Hence the total increment in value will have been 5-97 

 per cent. 



This is the percentage of increment, both in quality and 

 contents, which in the above example will have been yielded 

 on the capital value represented by the present crop of timber. 



For practical purposes, such an estimate is invaluable. 

 It will help, along with other sylvicultural considerations, 

 to govern the treatment which any particular crop is to 

 receive. For crops approaching maturity, the percentage 

 arrived at, as indicated above, may be taken as approxi- 

 mately equal to the percentage that will actually be earned 

 by allowing the present crop to stand for the period under 

 consideration. 



3. Total Increment on Invested Capital. 



To be strictly accurate, the percentage will not be quite 

 so great, as the value of the land must be taken into consider- 

 ation, thus increasing the capital upon which the return is 

 obtained. And, so also, the return will be lessened by the 

 annual outgoings in respect of the land and crop. 



Therefore, it is necessary to find the total increase in 

 value and to express this as a percentage on the total capital 

 represented by the crop and the land. However, in> order 

 to arrive at the exact percentage increment, the outgoings 

 must also be taken into account by increasing the capital, by 

 such a sum as represents the net annual outgoings (i.e., total 



