INSTRUMENTS TSEFUL TO A WOODSMAN. 



101 



line on the right-hand horizontal scale. This number indicates 

 the distance from the level of the observer's eye to the base of the 

 tree, and is added to the number before secured, which gives the 

 total height of the tree. If the observer should be standing so 

 that the level of his eye is below the base of the tree, he should 

 first determine the height from the level of his eye to the top of 

 the tree, then the height from the level of his eye to the base of 

 the tree, and subtract the last result from the first, which gives 

 the true height of the tree. Cost about $10. (See fig. 9.) 



Fig. 9. — Manner of using Faustmann's height measure. 



A cheaper form of this instrument has a wooden frame and slide, 

 and scales printed upon strips of paper pasted upon the frame. 



Forest Service Standard Hypsometer. 



For use on the National Forests, and in its investigative work 

 elsewhere, the Forest Service has adopted a standard hypsometer. 

 The following instructions for its use have been issued :fl 



Stand 100 feet from the base of the tree which is to be measured. 



o From "Instructions for Making Forest Surveys and Maps," unnumbered 

 1^ circular of the Forest Service, United States Department of Agriculture. 



