VOLUME INCREMENT OF SINGLE TREES. S3 



The tree having heen divided into a suitable number of 

 sections, each is cut through in the middle, the number of 

 concentric rings counted and the diameter at the several ages 

 measured. The measurements are best plotted, so that a 

 representation of a longitudinal section through the tree is 

 obtained. For this purpose, the heights of the several cross 

 sections from the ground are marked on a vertical line, which 

 represents the axis of the stem; also the heights which the 

 tree had obtained at successive periods of its life. Next, the 

 radii of the cross sections are marked on horizontal lines and 

 the points thus obtained connected by a series of lines, which 

 represent the stem curves at the several stages during the life 

 of the tree. From the data thus obtained, the increment 

 throughout the several periods of the life of the tree can be 

 calculated. As the thickness of the bark at former periods 

 cannot be ascertained, these investigations can refer only to 

 the increment in wood, exclusive of bark. 



The following example will explain the procedure : — 



Analysis of a Scotch Pine Tree. 



The tree was cut up into nine pieces, which gave the 

 following ci'oss sections : — 



Section I. taken at foot of tree, showing 97 concentric rings. 

 II. taken at 5 feet above fifround ,, 95 ,, ,, 



g2 



