APPENDIX. 



2o 



kiud of laud produce .64 of a t'ul)ic foot. Ou tlie Hue up from; 11, 

 therefore, we will mai-k another poiut, uearlyjhalf way up between the 

 lines across from 6 and 7. lu the same way the volume of the yearly 

 growth at all sizes of the tree is plotted, when the points may for clear- 

 ness* sake be connected bj- a curve. The rise in this curve then shows 



^ S 



o 



•|.6 

 f ^ 



•S 



.1 



o 



Mixed land. 



Spruce land— quality I. 



— — Spruce land— quality II. 



Diameter of tree— inches. 



at a glance gain in the yearly accretion. Rapid along to about 11 inches 

 in diameter, its rise there is less rapid, but it still continues to rise, never- 

 theless, throughout its length as here drawn. Plotting the facts for the 

 spruce laud of first quality shows much the same thing. When, however, 

 we come to the land of poor rjuality the relation of things is quite differ- 

 ent. The curve falls in the first place much below that characteristic of 

 the better soils. But further than that it is to be noted that the last of 

 the line is horizontal. Growth then, as was seen in the tables, has ceased 

 to increase and is holding its own. 



One more fact about these curves remains to be pointed out. The 

 curve for mixed land is seen to cross the other two, which means that 

 while for trees 10 inches and upwards the volume growth is greatest 

 on mixed land, for trees 7 inches and smaller it is greater ou the spruce 

 laud. Tliis is perhaps more apparent than true, and if true more interest- 

 ing than valualjle. But it does look reasonable. These trees stood in 

 laud that had been cut through, and in hard wood land far more would 

 be left to shade the small trees than in pure or nearly pure spruce timber. 



With what has gone before a diagram representing the percentage 

 growth of the same stands and sizes of trees will perhaps be understood 

 without explanation. 



Mixed land. 



Spruce land— quality I. 



Spruce land— quality II. 



