162 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
none can say with certainty, or even with probability, that a 
certain class of timber on a certain area will be worth any definite 
price per cubic foot in 60, 80, or I0o years’ time, as the case 
may be. We have, it is true, existing prices to work upon, but 
these are of little value beyond giving us some idea of the way 
in which the prices of timber are affected by size of individual 
trees, distance from railway or market, and so forth, enabling us 
to fix, with some probability, relative but not absolute values. 
Such approximate estimates, however, may be easily affected by 
changes in industries which now use timber as their raw material ; 
or by an increase or decrease in the costs of conversion or transit. 
That such changes are likely to occur in the future, there seems 
to be good reason for believing, but how far they will go, none 
can say. At the present moment it is absolutely impossible to 
make a reliable estimate as to the future value of any given 
quality of timber in districts where it is constantly coming on the 
market, and where the manner in which its price is affected by 
local surroundings is fairly well known. It is evident, therefore, 
that such estimates in connection with remote districts, in which 
timber has never existed or been sold within living memory, 
are practically valueless, and that the question of what 
constitutes a profitable yield can only be answered within 
fairly wide limits. 
Several important points in connection with this question, 
however, are worth considering. These are, first, the probability 
or otherwise of timber generally increasing in value, and second, 
the size to which individual trees can attain on the land proposed 
for planting. An increase in the price of timber has long been 
predicted. Ancient timber merchants tell us that their grand- 
fathers had sad forebodings of the coming timber famine, and 
students of old forestry literature will recollect that Evelyn, and 
writers before Evelyn, lamented the growing scarcity of timber 
in their time. But imports of timber still continue, and prices do 
not show any indication of short supplies at present. Probably 
the fact is that the existing supplies of timber are sufficient so 
long as the supplies of iron and coal hold out, for it must be 
remembered that wood is used for many structural purposes 
because it is cheaper and lighter than iron, and not merely 
because the latter is unsuitable ; while its extensive use for fuel 
is prohibited because it is dearer than coal. For many pur- 
poses, therefore, high-class timber could be dispensed with if its 
