66 



tbe quantity of water they displace when suhmerged), or by 

 the water-method and weighment combined. For the 

 water-method special vessels, called xylometers, may be 

 employed. In the combined system, samples of each kind 

 or class of wood are successively weighed and measured by 

 the water-method, and the contents of the entire quantity 

 in each class are then worked out by means of simple 

 proportion. Figures expressing specific gravity canoofc 

 be employed ; since the specific gravity of wood varies — not 

 only according to the amount of moisture present but — even 

 in one and the same tree according to the part from which 

 the wood has been derived. 



The most rapid way of measuring small wood on a large 

 scale is to stack it cut up into billets of the same length, tlie 

 width of each stack being equal to the length of the billets. 

 The contents of a stack will be equal to length x height x 

 common length of the billets. The length of a stack built 

 up on a slope must be measured horizontally. 'J he above 

 formula will give us only stacked contents. To reduce the 

 latter to solid contents, we must determine, by the water 

 method or by the combined water and weighment method, 

 the exact volume of a sufl5ciently large number of stacked 

 units, thereby obtaining the ratio between solid contents and 

 stacked con tents. To obtain the solid contents of a stack 

 it is then necessary merely to multiply the stacked contents 

 by this ratio which may be termed the reducing factor * 



In connection with the determination of the solid con- 

 tents of stacked wood it is obvious — 



(a) That the longer the billets or the less carefully 

 built up the stacks, the less will be the solid 

 contents. In careless stacking billets often lie 

 across one another. 



(6) That the thicker or more regular-shaped the bil- 

 lets, or the more carefully built up the stacks, 

 the greater will be the solid contents. 



(c) That the larger the stacks, the greater will be the 

 reducing factor. 



When bark is sold se parately its quantity may be 



i„^ * ' rj '""°"'''g '•Sr^'es may bo accepted as average factors fot converting stacked 

 into BOlin contents : — ° 



Split woort . 065 to 0-80 



Koiind billets (large) 50 to 0-65 



Ditto (medium) 0-3u to OSO 



hmall stuff, Btnnipg and roots . . . 0-15 to 0-30 



