THE PROBLEM OF MAKING VOLUME TABLES 581 



in accord with cruising practice. Professor Chapman has pointed out- 

 that the use of total height tables will forestall the cruiser's error in 

 assuming a different intensity of stem utilization from that assumed by 

 the maker of the table, but it is not clear to me that this would be so in 

 practice. 



I will leave this interesting point to be decided by those who perhaps 

 may later study the subject more deeply, with a view to standardizing 

 our practice. 



A Fixed or a Graduated Top Diameter 



A volume table may be made with a lixed top diameter limit — say, 8 

 inches — for trees of all sizes, or it may assume a graduated top diameter 

 limit coincident with actual utilization, namely, a low limit, 8 inches 

 for the small trees and a larger one for the big trees. If a fixed top 

 diameter limit is used, the cruiser must add enough to his allowance 

 for breakage and wastage to make up for the portion of the tip between 

 the actual used point and the 8-inch point. In a recent article Professor 

 Chapman has pointed out that it is the natural tendency for a cruiser 

 to take his merchantable length merely to the actual point of mer- 

 chantability, even if he is using a table of a smaller fixed top diameter, 

 and, furthermore, that the error so introduced into his cruise is much 

 greater than the scale of the tip so ignored. A large error is intro- 

 duced by his tallying a tree in a lower height class than it belongs, for 

 it gives it a different shape and volume throughout its lower logs. He, 

 therefore, strongly recommends a graduated top diameter, based on 

 actual logging practice. There is this to be said, however, that the 

 volume table maker would have to use his judgment in determining 

 that actual merchantable point and his judgment might not agree with 

 the cruiser's. Perhaps it is better to give the volume table maker no 

 latitude and tie him down to some definite point. It should be as easy 

 for the cruiser to conform to this practice and estimate the height to 

 a point at an absolute fixed top diameter as to an hypothetical point 

 at the top of merchantability. 



The Length of the Sections 



In the construction of most Service tables the measurement of 

 the bole has been taken at 16-foot intervals and the top of the tree 

 divided into shorter lengths, in accordance with our scaling practice. 



2 Proceedings Society of American Foresters, Vol. XI, No. 2, p. 221, 



