58 



VOLUME OF WHOLE WOODS. 



c. Robert Hartufs Method. 



In Draudt's and Urich's methods each sample tree repre- 

 sents the same number of trees. As the volume increases 

 rapidly with the diameter, it follows that a sample tree in a 

 class or group of small diameter represents a much smaller 

 volume than one in a class or group with a large diameter. 

 For this reason Eobert Hartig argues that the number of 



MEASUREMENT OF VOLUME ACCORDING 



