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 
277-278, 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 169, 262, and 275. 
