1900. 



AMERICAN FORESTRY ASSOCIATION. 



77 



:ained by measurement, is 3^.1 cubic feet, 

 :he " absolute factor of shape " would be : 



V' or -45- 



Where the forest growth is somewhat 



.miform the factors of shape of the trees 

 "elled for each species may be averaged 

 separately for that species to obtain its 

 'actor of shape. Where there is a wider 

 ange in the sizes of the trees, however, 

 :he factors of shape for these may be found 

 ?y interpolation on cross-section paper as 

 n the case of the height-curves. 



4. Whenever the branches of trees are of 

 /alue their volume should be ascertained. 

 Fhe trees taken for the stem volume meas- 

 urements can be utilized as sample trees 

 :or this purpose, their branches being 

 stacked in cords, separately for each 

 species, and the results reduced to solid 

 :ubic contents, .7 being the reducing 

 iactor. 



The following example will show how 

 :he measurements mav be tabulated and 



j 



:he volume computed : 



fi?= diameter of tree at 

 breast-height. a=stein above 

 breast-height. c=the cor- 

 responding cylinder. b = 

 stem below breast-height, 

 portion of the stem in- 

 cluded in the "factor of 



shape." = " absolute fac- 

 tor of shape." //"= total 

 height of tree. 



Computation for Beech. , for the 

 stem portion above breast-height. (See a 

 in the diagram.) 



Sample tract of 3.8 acres, being i per 

 :ent., in a Beech and Oak forest at x. 



Total, 257.14 



Total, 



8602.4 



b. For the stem portion below breast- 

 height, excluding the stump left on the 

 ground. (See b in the diagram.) 



Breast height, 4 ft. 3 in. 



Less height of stump, i " 3 " 



Length of b, excluding 



stump, 3 " o " 



Total basal area (column 



3 in the table), 257.14 sq. ft. 



Product (equalsvolume), 771.4 cu. ft.f 



* The figures in column six were obtained by 

 the multiplication of those in the three columns 

 preceding ; or, in other words, by reducing 

 with the aid of the factors of shape the contents 

 of the imaginary cylinders represented by the 

 figures in columns three and four. 



t It will be noticed that no allowance is made 

 for the flare of the roots, or the tapering at the 

 butt end of the stem. The difference would be 

 slight and may be allowed to cover part of the 

 breakage and waste. 



