304 



IMPROVING THE ACCURACY OF TIMBER ESTIMATES 



a marked degree. The only reason that such individuals have in the 

 past continued to practice timber cruising as a profession is the almost 

 complete absence of a reliable check on their results for years at a 

 stretch, and the comparative indifference of purchasers to the accuracy 

 of estimates due to a rising market and a plentiful lumber supply. 



Standing timber cannot be " measured." There is always a residual 

 error in the closest work. Hence the use of the term " estimates." 

 Although the only basic check on estimates is the measurement of the 

 timber after it is cut, yet it is possible, by the use of intensive methods, 

 to measure plots of standing timber so closely that they will serve as 

 checks on individual estimators. 



An example of this check is cited below in the case of a Minnesota lumber com- 

 pany, which in 1907 required each of its timber cruisers to estimate an area which 

 had previously been carefully calipered and measured with a volume table and was 

 afterwards cut and checked out with these measurements. The results speak for 

 themselves. These men were given all the time they desired to make this estimate. 



TABLE XLV 



Comparative Estimates on a Tract of 40 Acres 

 Board Feet 



Number of cruiser. t No other species estimated by these four cruisers. 



