42 PRINCIPAL KINDS OF EXPLOITABILITT • 



employed in the manufactures, which need it most of all, and which 

 would therefore pay more for it than other timber using trades. We 

 thus see how, without being exactly proportional to their respective 

 degrees of utility, the prices of the various classes of woods, accord- 

 ing to species, size and quality, indicate which of them are most m 

 demand, are most useful to the persons usins; them . On the other 

 hand, it is evident that the sum total of utility of the produce of a 

 forest is the combined result of the quantity yielded and the utility 

 of each separate category according to its nature. Hence if it is 

 desired to derive from a forest the highest sum total of utility of 

 which it is capable, we must endeavour to obtain from it the most 

 valuable woods in the greatest quantity possible. 



For those proprietors who do not themselves use the wood, but sell 

 it, the price of this wood is a measure of its utility for them. The 

 money value of the wood is of course the income obtained from the 

 forest, and is the product of the quantity and the selling rate of each 

 ilesciiption of wood ; thus income is proportional to the quantity of 

 the various, kinds of produce and the price of unit of quantity. 

 Now since the most useful woods are also the dearest, it follows that 

 a forest that yields the highest sum total of utility, yields also the 

 largest income. 



For those individuals who are in a position to speculate with the 

 funds at their disposal, and iu so speculating, to sell or to purchase 

 forests, for them forests constitute simply an investment, like any 

 other business, for their money. For them a forest is the more pro- 

 fitable, the larger the income it yields relatively to its capitalised 

 value. This relative income is directly proportional to percentage 

 of profits ; and hence they regard forests chiefly from the stand-point 

 of profits. 



Thus the owner of a forest may seek to obtain either the most 

 useful produce, or the largest income, or lastly the highest profits on 

 capital invested. But, as we have just seen, the first two objects are 

 compatible with one another ; they are both realized at the same age 

 and under the same circumstances. Hence we have two generic 

 classes of Exploitability. The one corresponds to the maximum 

 usefulness of the timber produced, and has for its essential object the 

 supply of the country at large ; the other corresponds to the highest 



