754 Forestry Quarterly 



Practically the same relation, with different figures, to be sure, 

 is found in fir and beech; thus in fir for a 50 cm tree the pieces 

 with top diameters 42 32 24 18 15 12 7 cm 



represent 28.9 81.8 94.7 97.9 98.9 99.7 100 per cent of the 

 timberwood volume of the tree, no matter what height. In 

 other words, with the same d.b.h. the shorter stem gives percentic- 

 ally as much of certain sizes as the longer stem. This is true 

 within an error of 1 to 2 per cent, rarely over 2 per cent. Only 

 in the first (largest) class are the differences somewhat greater. 



The author explains this peculiar relation by reference to the 

 behavior of form factors and by the fact that in proportion as the 

 shorter stem is less in volimie than the longer, the assortment con- 

 tents decrease, but the percentic relation remains the same. The 

 tables, of course, represent average values, and hence in the single 

 case considerable differences may occur. Spruces of the hill 

 country and of the mountains did not show enough difference to 

 make different tables necessary, nor did mixed forest show an 

 influence on this percentic relation. But the influence of specific 

 shaft form differences may make itself felt in very tapering and 

 very cylindrical stems. Schiffel's form quotient is declared of no 

 value in this connection because the diameter at half the height 

 is practically too cumbersome to ascertain, and practical use of the 

 tables is their object. The author, to aid in judging the form, 

 gives in the tables the average diameter at 5m, which in the given 

 case can be either judged or measured by caHpers on poles or 

 otherwise, furnishing judgment whether the tree is more or less 

 deviating from the normal form. There is also given a correction 

 table which, to make allowance for the form, reduces the d.b.h. 

 by given amounts for different diameter classes, when the corres- 

 ponding assortments are found under the reduced diameters. 

 Since, however, these tables like any other volume tables are not 

 to be used for estimating of individual trees, but only of groups, 

 errors of 8 to 12 per cent, which might occur in individual cases, 

 do not vitiate the use of the table without making allowance for 

 form differences. 



A special, extended investigation into the difference of ascer- 

 taining the volimie by 2-meter sections and by use of the middle 

 diameter and full length showed that the latter measurement 

 gave, as a rule, too small results, except with a top diameter of 7 

 cm, in which case it may sometimes be too low. With increasing 



