FULL STEM. CUBIC FOOT VOLUME TABLE 



33 



values and draw smooth curves for each one of the remaining 

 height classes. Label each. If any of these height classes con- 

 tain but few or chiefly abnormal trees, the curve for this class 

 must be interpolated between the next higher and lower classes. 

 4, From each height curve now read the average volume for the 

 respective average diameters in 2-inch classes by taking the 

 reading at every even inch. 

 . Averaging the Heights. — Up to this point we have evened off the 

 volumes according to the average diameters, irrespective of heights. 

 Hence it will now be necessary to determine what the average 

 volumes will be according to the average heights. 

 1. On a piece of cross-section paper lay off heights as abscissa; and 



volumes as ordinates. 

 ~ 2. Now construct a set of curves similar to those constructed under 

 ''rt," except that a separate curve is constructed for each diameter 

 class, using the new volumes read from the first set of curves on 

 the average heights. Use for the heights in this plotting the 

 value indicating the cla'^s. 

 3. Read off the values for every even 20 feet and tabulate in the final 

 form as follows: 



Label every curve of this exercise completely, and put a legend on 

 the final table showing the type of volume table constructed, the 

 species, the number of trees upon which the table is based, the 

 unit of measure, and the diameter limit used in computing the 

 volumes of the trees. 



D. /^e/cre^e.s.— Numbers 39, 41, 42, 43, 44 and 62. 



E. Discussion. 



1. Of what use is a volume table? Can it be applied accurately for 



securing the value of a single tree? Why, or why not? 



2. In what respect would the method of procedure, outlined above, be 



varied if the table should be constructed in board feet instead of 

 cubic feet? 



