328 JOURNAL OF FORESTRY 



in practice the use of two sets of volume tables/ H. H. Chapman 

 in a recent article^ has called attention to the very point which it was 

 necessary to consider in actual operations involving the use of these 

 two tables, which is the top diameter on which the log volume table 

 is based. Of the two volume tables employed one includes all timber 

 which would be removed under the closest current utilization 

 in this section ; the other table, which is known in our practice as 

 "One and Two Log Tables," gives the contents of butt and of the 

 butt and second logs in trees which contain two or more logs ; that 

 is, it is based on larger top diameters than the standard tables. By 

 using the butt and second log tables, only those logs are considered 

 which are reasonably clear. The preparation of the butt and the 

 butt and second log tables was in itself a comparatively simple matter; 

 the difficulty has been the technique of determining the conditions 

 on each tract to which each of the tables should apply. The condi- 

 tions on most tracts are such that it is not necessary to employ two 

 sets of tables. 



Correlation of Volume and Value 



If there were only one or even two species to consider, correlation 

 of volume and value would not be a difficult matter, but with from 

 ten to twenty merchantable species having different logging costs 

 on account of difference in weight and hardness and having different 

 values for the same trade grade of lumber, there must necessarily 

 be extremely close cooperation between the lumberman-appraiser who 

 determines the classes of merchantability and the chief of party of the 

 volumetric survey or cruise in order to insure accuracy of results. 



In the absence of such an understanding, stumpage values are likelv 

 to be too high and the estimated volume of merchantable timber 

 excessive. This is the tendency rather than for the error in one to 

 counterbalance the error in the other. 



The lumberman-appraiser or engineer who develops the system 

 of exploitation and determines the amount of different grades of 

 lumber in the timber by species and stand classes has in mind the 

 fact that logs of specific grades cannot be removed profitably except 



* Circular letters; Volume tables, Mensuration, June 4, 1913, and June 11, 1913. 

 The earlier letter called attention to the error in using volume tables having too small 

 a top diameter; the second transmitted special volume tables based on a large top 

 diameter and gave instructions relative to their use in connection with other 'or 

 standard volume tables. 



5 Proc. Soc. Am. For.. XI, 185, 1916. 



