CHAPTER X. 



FOREST MENSURATION. 

 MEASUREMENT OF SINGLE TREES. 



Trees which are to be Cut May be Considered in Two 

 Classes, in the first of which comes all those which contain 

 timber material, and in the second those which are too 

 small to be of value for timber. The material of the 

 first class is in the main part available for timber, and in 

 part for firewood, while the stump, smaller limbs, and 

 leaves are waste; the material of the second class may 

 be used in part for firewood, fence-posts, etc. For tim- 

 ber purposes, the cubic contents of the wood only is con- 

 sidered, while for firewood the bark is included in the 

 calculation, so that we may measure part of the tree with- 

 out bark and part with bark on. For timber, usually 

 only the main portion of the trunk is considered, espe- 

 cially in coniferous woods, but for firewood all limbs that 

 will make a stick of cord wood must be included. In 

 this discussion we will consider only the trunks of trees, 

 as the volume of the limbs must be determined separately, 

 but in the same way. 



The Volume of a Standing Tree can be gotten at only 

 roughly, as there is no geometric figure which exactly 

 represents the shape of the trunk, the latter varying much 

 under different conditions of growth. The volume of 

 a paraboloid, the geometric figure which approaches 

 nearest to the form of a tree, is equal to the product of 

 the basal cross-sectional area by one-half the height. The 



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