EGBERT HARTIG S METHOD. 



59 



sample trees in each class or group should be proportionate to 

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

 As the volume is fairly proportionate to the basal area, Eobert 

 Hartig forms groups which contain equal basal areas. He 

 divides the total basal area of the wood by the number of 

 groups which he proposes to form ; this gives the basal area 

 to be allotted to each group. After having placed in each a 

 sufficient number of trees to give that basal area, he calculates 



TO ROBERT HARTIG'S METHOD. 



