488 JOURNAL OF FORESTRY 



and value is much less than in B, but from the opposite reason, namely, 

 due to inferior size of trees, with larger numbers. The total increment 

 in the nine years was greater in B than in C, but again the percentic 

 production was 1 per cent smaller; the position of C in percentic 

 relation lies between A and B. 



The consequence of an insufficient thinning can then in this respect 

 be inverse to that of a too severe thinning. In the latter case the lower 

 product has reference more to volume than to value, since it has to do 

 with larger-sized trees, which command, per unit of volume, a higher 

 price. 



While on the whole the annual average increment, both in volume 

 the value, in C is superior to A and B, this does not necessarily imply 

 the same relation at all times ; an enlarged volume may not produce a 

 similar value increment. 



In examining six phases of development, the difference in volume 

 was four times found in favor of B, but the difference in value five 

 times to the advantage of A; only in two of the five cases was the 

 difference of volume and value credited to the same plot — once to A, 

 once to B — showing that oscillations in volume and value production 

 at various stages of development as a consequence of thinning take 

 place. 



From these comparisons it can be deduced that if the 29 per cent 

 thinning was too severe, the 23 per cent is too moderate, and the 25 

 per cent more advantageous, the optimum limit. The author advocates 

 such small experiments to be undertaken under the varying conditions 

 by the practitioners, when in a few years the proper degree can be 

 determined. Altogether, while experiment stations have their value in 

 developing principles, individualism in research, the author thinks, 

 would be of more immediate practical use. Especially in France, 

 where forest property is largely private, lack of initiative on the part 

 of forest owners is reprehensible. "Is it not strange that the owners 

 of 15,000,000 acres of woods beheve they can dispense with acquiring 

 technical knowledge, and that, within nearly a century, the number 

 of French students at the forest school has only been forty-five in the 

 average per semester?" B. E. F. 



Recherche de la limite optima d'intensite dans les eclaircies. Revue des Eaux et 

 F6rets, February, March, 1917, pp. 33-43, 65-72. 



