Forest Mensuration 205 



up his pacing. This estimate of 2 acres in every 40 is 

 5 per cent of the whole and the estimates obtained on 

 these two sample acres should be multiplied by 20 to get 

 the estimate of the 40. Some judgment is necessary 

 to see that these samples do not fall in timber too far above 

 or below the average. It is this element of uncertainty 

 that makes the partial estimates unsatisfactory, especially 

 with the beginner whose judgment is not sufficiently 

 trained- 



