14 



Forestry Quarterly. 



The following example, taken from actual measurements of a 

 White Pine section, shows the variability of results and the neces- 

 sity of judgment in choosing the proper diameter : 



The choice of the radius should be made with the eye ; choos- 

 ing the one where the annual rings show the greatest regularity 

 in width and curve. 



It sometimes happens that the average radius can not be 

 exactly found on the .stump of trees felled in regular logging 

 operations. The tree has been notched in such a way that the 

 place where the radius .should be located is in the rough slanting 

 surface of the notch ; or it may be that a spot of rot appears in 

 the place where the required radius should be drawn. As a gen- 

 eral rule, and preferably, such a tree should be thrown out of con- 

 sideration ; nevertheless in practice there arise cases when it 

 should be taken. It may be of a diameter especially needed for 

 completeness or in large timber the necessity of fully employing 

 the measuring crew when following the sawyers closel}-, without 

 interruption will make it expedient to use each tree without dis- 

 tinction. In such cases the measurements can be obtained with 

 sufl&cicnt accuracy as follows : 



