26 



A second method is to select a "sample plot" of known 

 area, preferably one-quarter acre. A circle with a 59-foot 

 radius, or a square 104 feet on a side, encloses one-quarter 

 acre. Caliper all trees on this plot, and obtain the volume as 

 above. The total volume will be to this volume as the total 

 area is to the area of the sample plot. 



A simple, but yet more uncertain, method is to count the 

 trees on the lot, pick five or six which appear to be average, 

 scale these by the volume table to obtain the volume of the 

 average tree, and multiply this amount by the total number of 

 trees. If one is not careful in selecting his average trees the 

 error is multiplied many times, so that this method is not 

 highly recommended. 



The simplest although not the least laborious way of getting 

 at the height of a stand is to cut down an average tree and 

 measure it with tape. Fallen trees can often be found on the 

 ground. Any instrument that reads angles, a measuring tape, 

 and the application of a little trigonometry will give the desired 

 results. There are several instruments constructed to give 

 by direct reading the heights of trees. 



There is a method of obtaining the height of a tree that is 

 fairly simple and requires no instrument but a stick which, 

 when stuck in the ground, will come to the level of your eye. 

 Set this stick in the ground at such a distance from the base 

 of the tree to be measured so that when you lie on the ground 

 with your feet at the stick the top of the tree and the top of 

 the stick are in line. The distance between your head and 

 the base of the tree is equal to its height. 



A caliper of great convenience for use in connection with 

 volume tables and log scales mentioned in this book consists 

 of a beam 36 inches long and graduated into inches and tenths. 

 At the left end is a rigid arm set at right angles to the beam, 



