76 



THE WHITE PINE. 



From the table it appears that the specific weight of the timber is quite independent of the 

 rate of growth, and that the individual variation generally moves within very narrow limits. The 

 diagrams (figs. 16 and 17) show the relation of weight for the different sections from the stump 



to 



30 40 SO 60 



Position . of discs, feet from ground . 



70 



SO 



90 



FIG. 16. Diagram showing specific weight of wood at different cross sections of the stem; also a decrease of weight from the stamp 



upward, and the similarity of the wood of different trees. (Five trees, over 200 years old. Dotted line indicates the average.) 



upward; the slightly greater weight of the older timber, as compared to sapling material, the 

 uniform decrease in weight from stump upward, and also the uniformity of the several individuals 

 of any group of trees is clearly apparent from the lines. The same decrease in weight from below 



a 



TO 



so 



ill' 



30 40 50 ttO 



Position of discs, feet from ground . 



Fro. 17 Diagram showing specific weight of kiln-dry wood at different points in the stem from ground upward: a, six trees, 200 to 250 



years old ; b, five trees, 125 to 160 years old ; c, seven trees, 100 to 125 years old j d, ten trees, 75 to 100 years old ; e, ten trees, 50 to 74 years 

 old ; /, eighteen trees, 40 to 40 years old : g, nineteen trees, 30 to 39 years old. 



upward is observed in the wood of any given period of growth; thus, the wood of the last forty 

 rings (next to the bark) was found to be as follows: 



llecreate in weight of the wood of the last (outer) forty rings in the several ditks from stump njucari:. 



