Al'PENDIX. 



23 



Xow liow long can a tree be profitablj' left to grow? IIow loug does 

 this increase in its 5'earl5' production continue? The same column of 

 figures answers this question. For fine points it could hardly be trusted, 

 but in regard to the general teadencj- there can be no mistake. There is 

 no slack in the rise of the growing power of the tree as far as it has been 

 observed. A tree 14 inches in diameter grows on the average more wood 

 per year than one 13 or "12. The longer it stands, up at least to this 

 point, the greater the production of the tree and the land. 



Entirely difterent is the course of the percentages. These are, to be 

 exact, the rate of growth of the tree at compound interest during the 

 last 10 years. These, it will be seen, have been steadily shrinking. As 

 growth adds to the volume of the tree, the addition of each year though 

 greater in actual volume bears a less ratio to the volume of the tree at 

 the time. Thus while at 8 inches in diameter a tree may grow .31.5 cubic 

 foot which is 4.2 per cent of its volume at the time, at 14 inches in diame- 

 ter a yearl}' growth of 78 cubic foot is only 2.5 per cent of the volume at 

 that time. Consideration of the actual amount of growth will in most 

 cases incline one toward conservatism in the handling of timberlaud 

 more than that of percents. 



Spruce on Spruce Land of First Qualitt. Land Uneven and Well Drained. 

 Soil Generally Small in Quantity, Covered with Moss. 





Computed Results. 





Growth Last 

 Ten Years. 



5 ^ 



1) c — 

 a O.S 



a; 





Same Evened by Drawing Curves 

 FOR Volume and Per Cent. 



I? 





Growth Last 

 Ten Years. 



a . 



r: X ;j 



d C - 



I 



n 



8 

 9 

 10 

 11 

 12 

 13 

 14 



5.9 

 7.6 

 10.3 

 14.2 

 17.7 

 21.6 

 25.8 

 31 



113 



1.14 



1.22 



1.10 



1.3 



1.2 



1.26 



1.17 



10.5 



14 



17.5 



21.5 



26 



31 



1.1 



1.15 



1.2 



1.23 



1.23 



1.23 



1.22 



1.2 



4.3 



4.1 

 3.7 

 3.25 

 2. J) 



i\\ 

 2.4 

 2.2 



.26 

 .33 

 .39 

 .45 

 .51 

 .56 

 .02 

 .68 



Three hundred and forty trees observed in till, mostly from Dennis, Brassua, 

 1, R. XIV, and A and I, R. XII on Roacli River. Mostly underlaid by slates. 

 Average height above sea about 1,200 feet. 



