COLLECTION OF DATA FOR VOLUME STUDIES 11 



(b) Next, he measures the D.O.B. at the stump, again taking an 



average of the longest and shortest diameters, and the average 

 width of bark determined by t\^o or more measurements. 

 Every time he calls out a measurement he should wait for 

 the notekeeper to repeat it. 



(c) In a similar manner he proceeds along the bole and obtains the 



D.O.B. , and width of bark at the top end of each section. 

 Should the sections not be measured in the same lengths as 

 cut by the logger, the width of bark will have to be secured 

 by chopping through it, taking care to have the cut surface 

 perpendicular at the point where the D.O.B. is secured. 

 Often when the saw cut is not over a few feet from the point 

 where the measurement is to be taken, or in rough work, the 

 width of the bark of the nearest saw cut may be entered as 

 that of the section being measured. A few trials will readily 

 show to what extent this is permissible. 



(d) The D.O.B. at the middle of the total height of the tree will 



be measured in order to compare the two methods of com- 

 puting volumes of trees explained in Problem 13. It is not 

 required in ordinary work. 



The Notekeeper. 



(a) The notekeeper should always repeat the values as they are 

 called out to him as a check in tallying the measurements. 



(6) Before leaving a tree he should check over his tally sheets to 

 ascertain whether any necessary measurements have been 

 omitted. At odd moments he should also make the follow- 

 ing calculations and record them in the proper spaces on the 

 tally sheet. 



1. Diameter inside bark at each section, obtained by doubling 



the width of bark and subtracting from the D.O.B. 



2. The total height, obtained by adding together the length of 



all sections, including stump and tip. 



3. The used length, which represents the sum of the log sections 



just as used by the logger, and hence does not include 

 stump and tip. 



4. The merchantable length. This may be the same as the used 



length though not necessarily.' It is usually not when it 

 is determined between a fixed diameter limit in the top, 

 irrespective of the sections as cut by the logger. 



E. Discussion. 



1. Supposing that the field data were to be obtained for the construction 

 of a volume table on the D.B.H. only, and intended to show the con- 

 tents of trees as cut by the logger, how would the above method of 



