LOG RUN OR AVERAGE LOG METHOD 143 



Where greater accuracy is sought, and especially, where the diameter 

 of the tree is measured at 4| feet rather than guessed at, tables may 

 be compiled from the actual measurement of the upper diameters of 

 felled trees which show the average taper for each log, for trees of given 

 diameter and height, and with the width of bark actually measured 

 and deducted for the top of the butt log. These tables will enable 

 the cruiser to tally the sizes of his logs without relying on his eye for 

 more than the determination of total height or number of logs. 



Log grades (§ 87), when used in timber estimating, require the tally 

 of the top diameter of the logs, separated into grades. This permits 

 of the separate totaling of volume in each log grade on the tract. 



120. Log Run or Average Log Method. The tallying of the actual 

 size of every log on a tract is so slow and expensive that it is possible 

 only when the timber is large and scattered. Woodsmen, who use the 

 log as the unit of estimating, do not usually tally any sizes but obtain 

 the total number of logs on the area by five steps, namely: 



1. A count of the trees. 



2. Decision as to the average number of logs per tree. This may 

 be in halves or even quarters, as 3J logs per tree, referring of course 

 to the standard length adopted for estimating. 



3. The board-foot contents of an average log. 



The last point is based on familiarity with the results of scaling logs 

 cut from similar timber, and the cruiser expresses it in terms of " log 

 run " or number of logs required to scale 1000 board-feet of lumber, 

 as illustrated by the following figures; 



Log Run. Contents of Average Log. 



2 per 1000 board' feet. 500 board feet. 



5 per 1000 board feet. 200 board feet. 



10 per 1000 board feet. 100 board feet. 



20 per 1000 board feet. 50 board feet. 



40 per 1000 board feet. 25 board feet. 



The " log run " increases as the average log content diminishes. 

 Knowing the log run, or guessing at it, the estimate in board feet is 

 obtained by: 



4. Multiplying the total number of trees by the number of logs per 

 tree. 



5. Dividing the total number of logs by the log run or number of 

 logs in 1000 board feet of lumber. 



This method was used by many old-time cruisers in the Lake States 

 region to the exclusion of all others. When old and young, or large 

 and small timber is found on the same tract, separate classes are usually 

 made in the count. 



