120 



PROPERTIES OF WOOD. 



the percentages of bole, branch- wood and root-wood of different 

 species are as follows : 



Standards over coppice show different percentages of bole, 

 as they are much more branchy than high forest trees, 

 especially when old. Lauprecht gives the following : 



As regards cylindricity of stem, the cleaner the stem is 

 from branches the more cylindrical it is. Density of crop 

 produces cylindrical boles ; open growth, conical boles. It 

 has been asserted that the upper part of the stem is nourished 

 better than its lower part. Metzger and Schwarz consider the 

 better nourishment of the top of the bole as the necessary 

 consequence of the gradual construction of the tree according 

 to the laws of equilibrium. 



A measure of cylindricity is the form-factor, or the ratio 



