CRUISING WITHOUT THE AID OF A VOLUME TABLE 47 



D. References. — Numbers 14, 56, 58 and 60. 



E. Discussion. 



1. Which method is most accurate? 



2. Which method is the most rapid? 



3. Which method would you choose to cruise a given tract? Why? 



4. Can the first two methods be safely used by inexperienced men? 



PROBLEM 23. (Field and Office.) Cruising Without the Aid of a 

 Volume Table. 



Explanation: The object of this problem is to illustrate a method of cruising 

 a large tract of timber when there are no volume tables available. 



Directions : 



A. Equipment Required. 



1 Forest Service staff compass, or hand compass when the former is not 



available. 

 1 pair of tree caHpers. 

 1 field notebook with Forms 3 A and B. 



B. Parties and Organization. 



Men will be organized in two-man parties, one man acting as compass- 

 and tallyman and the other as caliperman. Each crew will cruise a 

 quarter section tract. One man will act as cruiser and the other as 

 compassman on the first eighty acres covered, and the second man as 

 cruiser for the second eighty. In this way each man will cruise one-half 

 of the tract. The men should assist each other in working up the data, 

 but each will hand in only the data for the area he has cruised. 



C. Method of Procedure. 



The estimate will be obtained by running two strips, four rods wide, 

 through each ''forty"; on each strip diameters breast high of trees 10 

 inches and over will be tallied; the heights will be obtained from a height 

 curve constructed from data collected in the field as suggested under 

 Section II; the volumes will be computed by means of the Spaulding 

 Rule of Thumb. 



Part I. Running the Strips 



The compassman will pace, run the compass line, and tally the sizes called off 

 by the cruiser who will take the D.B.H. to the nearest even inch of all trees 10 

 inches and over on the four- rod strip. 



The cruiser should be careful to look out for defects in the trees calipered. 

 As he approaches a tree when at a distance from it where he can see the whole 

 stem, he should look up the hole for conk, fungus or other defects. The volumes 



