(6) That the thicker or more regular-shaped the billets are, 

 or the more carefully built up the stacks are, the 

 greater will be the solid contents. 



(c) That the larger the stacks are, the larger will be the re- 

 ducing factor to be adopted. 



4. Measurement <>f Bark. 



"When bark is sold separately, its quantity may be determined 

 either by weighment or by ascertainment of volume. The solid 

 contents are calculated by means of reducing factors in the same 

 way as the solid contents of femall wood. Experiments give from 

 0'3 to 0*4 as the average factors for bark. It has been found that 

 the quantity of bark varies from 6 to 15 per cent, of the total 

 volume of the tree or crop. 



Chapter III. 



On the measurement of Standing Trees. 



In this case, unless ladders are used (a procedure that is hardly 

 practical and is not really necessary) only a siny;le diameter or 

 gi-rth can be measured directly, viz., near the base of the tree. 

 Any diameter above 6 feet from the ground must be measured 

 indirectly by means of special instruments, the best of which are 

 Winkler's and Saulaville's Dendrometers and Breymann's Univer- 

 sal Instrument. Obviously no direct measurement of the branches 

 is practicable, and their cubical contents can, therefore, only he 

 estimated from the results of special experiments, or with the help 

 of long experience. 



We have five different methods of estimating the contents of 

 standing trees 



1. Ocular estimation, without any measurement at all. 



. Estimation with the help of mass-tables, the height and 



girth at breast-height being accurately measured. 

 3. Estimation with the help of farm-factors, which serve to 

 -. , reduce, to the true contents of the tree or of any part of 

 the tree, the volume of the cylinder, whose height \B the 

 height of the tree and girth the girth of the tree 

 measured at breast-height. 



