VOLUME; TABLES 53 



they require values for different height classes. The data for these 

 tables are usually gathered in connection with regular timber cut- 

 ting, so that the results may not only be stated in board feet or cubic 

 feet, but may give the number of railway ties, poles, piling, cords 

 of pulp or cooperage stock, etc., and in this way the value of the 

 tree on basis of prevailing prices. 



This work may well be done by 2 men crews, and usually takes 

 the following measurements : total height ; height of stump ; number 

 of logs, and total length thus actually used ; clear length, and length 

 which could be used ; diameter breast high, outside bark ; upper 

 diameter of each log inside bark. The scale of the logs bases itself 

 on length and diameter and leaves out of consideration crook and 

 defect, as accidental. 



2. Volume tables based on Age, state the volume (and 

 usually height and diameter) of the tree, at the age of ten, twenty, 

 thirty, etc., years, and thus indicate the rate of growth of the tree. 

 The data are gathered by partial, or by complete stem analysis. 



a. Partial analysis. If in the process above described, the 

 rings on the stump are counted and thus the age of the tree is 

 ascertained, the data can be arranged according to age instead of 

 diameter and a table can be prepared which gives the volume of the 

 tree at different ages. That the same data can also be used to 

 prepare the table based on diameter, is evident. 



b. In Complete stem analysis the rings are counted on the 

 stump, at the end of each log, and usually at one or more cuts in 

 the top. In addition to being counted they are measured, from bark 

 in, at every tenth ring, so that a table and a diagram can be prepared 

 which shows the size of the tree at time of felling, ten years, twenty 

 years, etc., before felling. From this diagram and table a curve is 

 made for each tree and the rate for the several trees thus graphically 

 averaged. This is one of the most useful, instructive and reliable 

 lines of measurements in forest work. As far as any one tree is 

 concerned, the results are as accurate as the form of the tree permits. 



Only good trees should be used. A great deal of information 

 is obtained from one tree; thus a tree 150 years old tells of its 

 height, diameter and volume at ten, twenty, thirty, etc., years and 

 thus gives accurate information, which in the partial analysis would 

 require fifteen trees. In addition it presents the actual growth of 



