ROBERT HARTia S METHOD. 



The volume is obtained by the formula :- 



59 



y ^ 88-36 X 1,462-51 ^ ^^ .^^ 

 3-7B7 



. r. Robert Hartig's 3fefkoiI. 



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, Robert Hartig argues, that the number of 

 sample trees in each class or group should be proportionate to 

 the volume, which it contains, and not to the number of trees. 



TO Robert Hartig's Method. 



