Errors in Estimating Timber. 173 



Total 1560 72,032,640 72,110,980 o 64,339,820 — II 68,225,400 — 5 



The above table emphasizes more strongly the points brought 

 out in the first table. To bring them out more clearly the maxima 

 errors have been picked out and listed below, beginning with those 

 occurring on the largest area. Section 16, covering a total of 640 

 acres, has been omitted from this tabulation because it is a very 

 erratic section and a check on the ground showed that the original 

 estimate on it was very poorly made, being quite unreliable. 



TABLE III 



Greatest Errors (Per Cent.). 



Difference 

 Area 5 %Estimafe 10% Estimate betmee^i 5 and I0% 



Acres Tot. Est. By Spec. Tot. Est. By Spec. Tot. Est. By Spec. 



1560 II 17 5 12 6 5 



480 23 40 9 37 14 3 



160 36 75 25 68 II 7 



80 32 116 20 45 12 71 



40 71 179 38 III 33 68 



The first column in the above table shows the area of the tract 

 considered. The second column shows the greatest mistake 

 found in the total estimate of each tract by the 5 per cent, method, 

 while the third column shows the greatest error in any one 

 species in the tract by the 5 per cent, estimate. Columns four 

 and five are repetitions of columns three and four respectively, 

 but consider only the 10 per cent, cruise. Column six shows the 

 difference between the greatest error by the 5 per cent, and the 

 10 per cent, estimate, when the total cruise of the tract is taken 



