170 A MANUAL FOR NORTHERN WOODSMEN 



tables have frequently been based on diameter alone. In 

 other cases and this is essential unless a region is very 

 uniform in its timber growth height has been taken 

 into consideration as well. 



Thus many western and southern cruisers have made up 

 tables giving the contents of trees of each inch in diameter 

 and yielding 2, 3, 4, etc., logs as these would be cut in 

 local practice. Again, an old Adirondack manager made 

 up a table showing the number of spruce required per 

 cord of pulp wood for trees 7, 8, 9, etc., inches in di- 

 ameter, and short, medium, or tall, as the case for his 

 region might be. Local volume tables, thoroughly based 

 and used correctly, are the most reliable kind. 



General Volume Tables for business purposes are of 

 two varieties, the trees being classified either by total 

 height or by length of merchantable timber. The assump- 

 tion on which the first is based, that trees which have the 

 same diameter and total height do not, when taken in 

 numbers, vary in form throughout the region of their 

 distribution, may, with a caution on the matter of age, 1 

 be considered safe for most purposes. It is true, however, 

 that some Pacific Coast timbers, with a very variable 

 thickness of bark and the root swelling of large trees run- 

 ning above a man's height oftentimes, have to be handled 

 with special caution. 



The other variety of tables classifies trees in height by 

 the number of standard log lengths they will yield or the 

 height at which their boles attain a specified diameter. 

 Under this plan the point to be observed is brought nearer 

 the estimator. It is not, however, as sharply defined a 

 point as in the other case, while, as explained on pages 

 274-275, special opportunities for error arise through vari- 

 ability in lumbering practice. 



Another matter that has to be reckoned with in the 

 valuation of standing timber, and which becomes in some 

 species and regions a consideration of great importance, is 

 defectiveness in quality. This no general volume table can 

 allow for. It has to be worked out for each locality accord- 

 ing to the judgment or experience of the estimator. 

 1 See pages 101, 20$, and 277. 



