CHAPTEE IV. 



DETERMINATION OF THE VOLUME OF WHOLE WOODS. 



THIS chapter may be divided into three sections, according 

 to whether the measurements extend over the whole wood, 

 or over only a selected portion of it, or whether the volume is 

 estimated. 



SECTION I. MEASUREMENTS EXTENDING OVER, THE WHOLE 

 WOOD. 



The method demands a uniform treatment of the whole 

 wood, but a distinction may be drawn between the measure- 

 ment of all trees, or that of selected trees, called sample 

 trees. 



I. MEASUREMENT OF ALL TREES. 



Each tree is measured separately, and its volume ascertained 

 in one of the ways described in Chapter III. By adding up the 

 volumes of the several trees, that of the whole wood is obtained. 



As the method takes much time, it is, in practice, only 

 employed when the total number of trees is small, or when 

 the wood is of an irregular description. As a rule, the 

 following system is chosen, as it works more rapidly. 



II. DETERMINATION OF VOLUME BY MEANS OF SAMPLE TREES. 



The volume of a wood consists of the sum of the volumes of 

 the individual trees. The volume of each tree is calculated 

 according to the formula 



v = sxh xf, 



where s represents the basal area at a certain height, h the 

 total height, and / the form factor of the tree. In all cases 

 where s, h, and/ differ from tree to tree, nothing remains but 

 to ascertain them separately for each tree. In the case of 

 regularly-grown woods, however, there are always a number of 



