COMPUTATION OF CONTENTS. 105 



6-inch quarter girth will give contents equal to one- 

 fourth the entire length in feet. 



7-inch, one-third. 



8J-inch, one-half, 

 lo-inch, two-thirds. 

 12-inch, equal. 

 17-inch, twice. 

 2 1 -inch, three times. 

 27-inch, five times ; and so forth. 



If he can impress these on his memory he will soon 

 get into the way of rapid computation. 



Tables are used and can be kept in the book, so 

 that reference is easy ; but before selecting a table, it 

 should be ascertained whether the results given agree 

 with the rule laid down. 



If the sliding rule is used more time will be required, 

 and for large quantities we do not recommend it. We 

 do strongly advise, however, the beginner to make 

 himself by practice acquainted with its use, as it is 

 often most useful. As the work proceeds, the trees 

 must be marked, so that they should not be measured 

 the second time, as may easily be done in a large 

 wood. This mark should be on one side only, so that 

 by looking back they may be seen. If marked at 

 random, much running about is needed to satisfy any 

 doubt. 



In a large and thick wood, some care will be 

 necessary to avoid confusion. We have found it use- 

 ful to mark off sections by aid of white rods ; but 

 valuers must adopt their own plan to suit local circum- 

 stances. One thing, however, is absolutely essential 



