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stump for different diameters breast-high. It can be seen that with such a 
table, which is a “taper table,” the size of the average tree can easily be 
ascertained, and that all the data are in hand necessary for scaling its 
contents by any log rule or for computing its volume in cubic feet. 
5. Plot curves of total and merchantable heights based on D. B. H. 
for both black and white oaks. Also make up tables from curves show- 
ing the board foot and cubic foot contents of trees based on D. B. H. 
6. To get volumes based on age, plot the measurements taken under 
the heading “Distance on average radius from center to ring by decades” 
shown on the field sheet. Taking the stump section first, plot the diameter 
grown in ten years, by doubling the radius measurement each time. 
Diameter inside the bark is used as the ordinate and age as the abscissa 
for the curve. 
7. Repeat the same procedure for the other sections, or logs, marked 
1, 2, 3, 4, 5, and 6, on separate sheets of cross-section paper, and finally 
assemble all of these curves on one sheet. In this case the curves for 
different lengths are moved out to the age corresponding to the number 
of years required to grow up to that height from the ground. 
8. With such a set of curves of diameter-growth at different heights, 
read off the time required to grow a log of any length or any top diame- 
ter inside the bark by following with the eye a line from the D. I. B. 
across to the curve representing the length desired. Project a line down 
from that curve to the base line and read the age required for the growth 
from the ground of such length of log. 
9. After this set of curves is made, the results can be read off to 
form a table, and the volume of the logs can be computed, since their top 
diameters and lengths are known. 
As stated by Pegg (’19), working up the data from stem analysis 
sheets can be greatly facilitated by the use of an adding machine and a 
slide rule. 
