EOTATION FOR COMMERCIAL EXPLOIT ABILITY. 107 



Exploitability presents certain difficulties, which ought to be known 

 in order to be overcome or avoided. As regards the periodic 

 income realisable at any given age, say, for instance, at 25 years, 

 that sum is none other than the value of the standing crop at that 

 age. To determine it by actual experiment, the crop chosen for 

 the purpose should be complete, and placed under average condi- 

 tions of fertility ; without the first condition, the results obtained 

 could not represent the whole sum of production possible, and 

 without the second they could not be applicable to the whole 

 Working Circle generally. All this is a question of appreciation 

 and judgment, which is by no means very difficult to resolve. But 

 often and, we may say, in the majority of cases, crops above the 

 age fixed by the Rotation heretofore adopted, are entirely wanting, 

 and yet we must have them to obtain all the necessary terms of 

 comparison. Under such circumstances there is no alternative but 

 to seek out analogons types amongst the surrounding crops, for it is 

 impossible to picture to oneself, with any degree of accuracy, the 

 future state of a crop, by simply noting its present condition, and 

 arguing from it what the state of the crop will be so many years 

 hence. 



We have seen above that the age of Commercial Exploitability 

 varies with the customary rate of profits demanded from invest- 

 ments in forest property. But forests constitute, by their very 

 nature, great properties, which do not go into the everyday market 

 like smaller things. They have, therefore, no well established 

 market value. Hence the determination of the customary rate of 

 profits from forest property is as difficult as it is important. The 

 best way to obtain it is generally to take as a starting point the 

 customary rate of profits demanded from investments in cultivated 

 land — farms, for instance, a class of property _which has a great 

 analogy to forests. That rate is well known. The next step is to 

 enquire whether investments in forests in the particular locality in 

 question are expected to pay a little more or a little less than 

 cultivation ; this fixes approximately the rate sought, which is the 

 corner stone of all subsequent calculations. Although, with such 

 precautions, we may not be able to determine exactly the age of 

 Commercial Exploitability, yet this much we can certainly do, viz., 

 find out whether it would be expedient to lengthen or shorten the 

 present rotation. 



