APPENDIX A 



TABLES TO BE USED ALONG WITH BRANDIT'S 1 HYP- 

 SOMETER FOR ASCERTAINING THE HEIGHT OF 

 TREES 



EXPLANATION 



The measurer first reads the upward 2 angle to the top of the tree. 

 This upward angle will be the angle formed by a line horizontal with the 

 observer's eye, and by a line from the observer's eye to the top of the 

 tree. 



The observer must move backwards or forwards until the angle, as 

 read, is equal to one of the angles for which tables are given. When 

 such angle is ascertained, the horizontal distance from the observer to 

 the centre of the tree must be measured, and the height then ascertained 

 from the tables. To this, however, must be added 3 the height from the 

 ground-level to the place where a line, horizontal with the observer's 

 eye, cuts the trunk of the tree. 



For instance, an angle of 38 is read, and the horizontal distance 

 from the observer to the centre of the tree is 50 feet, and the vertical 

 distance from the ground-level to a horizontal line from the observer's 

 eye is 5 feet 6 inches. 



Then, on reference to the tables, a height of 39-06 feet is obtained. 

 To this must be added the 5 feet 6 inches. 



Hence, the total height of the tree = 39-06 + 5-5 feet 



= 44-56 feet. 



1 Or other instrument for measuring the angle. 



2 Vide Chapter XVII. 



3 This presumes that the observer's eye is not below the level of the base 

 of the tree. 



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