86 



THE WOODSMAN'S HANDBOOK. 



The total amount of timber on the area on which the trees are 

 counted are then determined as follows: Find from a volume 

 table, such as that given on page 181, the amount of timber in an 

 average two-log tree of each diameter, and multiply this amount 

 in each case by the number of trees of the diameter in question. 

 Add together the results thus secured for the total amount of tim- 

 ber in the two-log trees. Make a similar calculation for the three- 

 log trees, or the four-log trees. Then add together the total con- 

 tents of the two-log, three-log, and four-log trees for the total amount 

 of timber on the area. 



Another method is to estimate the total height of each tree when 

 measured and to group the trees in height classes as follows: 



The total amount of timber on the area may be determined in 

 the way described above, if volume tables exist which give the 

 contents of average trees under 60 feet, 60 to 80 feet, 80 to 100 

 feet, etc., in height. 



If no such tables exist but there are tables for trees of all heights, 

 the cruiser should measure in the woods the average heights of 

 trees under 60 feet, 60 to 80 feet, 80 to 100 feet, etc. He should 

 then compute the average diameter of the counted trees under 60 

 feet, 60 to 80 feet, 80 to 100 feet, etc. Knowing the diameter and 

 the height of the average tree under 60 feet, its content is secured 

 from a volume table of heights and diameters. This value is then 

 multiplied by the number of trees under 60 feet in height. The 

 contents of the trees 60 to 80 feet, 80 to 100 feet, etc., are found in 

 the same way, and the totals are added together for the total 

 amount of timber on the area. 



