FOREST commissioners' REPORT. 



107 



Table 7. — Diameters of l^apcr birch at i-foot intervals above the ground 

 bclozv breastheight, based on measurements of 300 trees. 



Tlie amount of solid wood in a stacked cord is influenced by 

 many factors, such as form, diameter, and length of sticks, and 

 method of stacking. Table 8 is based on measurements of 16 

 half-cord .stacks of unsea.soned paper birch spoolwood bolts in 

 the round and shows the influence of diameter on the solid con- 

 tents of the stack. The measurements show the high average 

 of Qv) cubic feet per cord for spoolwood bolts averaging from 

 5 to 12 inches in diameter, which indicates very clearly that 

 most birch liolts are smooth and straight. Ninety-six cubic feet 

 may therefore be assumed as equivalent to one cord and, with 

 modification depending on the average size of the sticks, used 

 as a converting factor in changing volumes from one measure 

 into the other. 



The proj)ortion of sap and heartwood varies more or less 

 irregularly with bolts of different sizes. While the larger bolts 

 contain absolutely more heart than the smaller ones, they may 

 not contain any more relatively. The measurements show the 

 average per cent of heart to be 6.9 per cent, and of sa])wood 

 82.7 per cent. In spite of the fact that birch bark is relatively 

 thin, it averages as high as 10.4 per cent of the total volume, 

 antl does not show any regular variation with changes in the 

 size of the sticks. 



The fuel wood is small, knotty, often fjuitc crooked, an 1 does 

 not pack closely. Measurements of two half-cord stacks showed 

 tlie high average of 274 sticks per cord, with the correspondingly 

 small avt. rage rolid contents of only 65.5 cubic feet per cord. 



