BRANDIS* HYPSOMETEK AND CLINOMETER. 25 



values of b c are obtained and can be marked on the instru- 

 ment. In this way the heights can be read off straight on 

 the instrument. For convenience sake the marks on the 

 instrument are cuts, so that the top of the staff may be more 

 easily seen. 



The instrument has the disadvantage that the marks are 

 very close one to another for heights over 30 yards. This 

 might be obviated to some extent by lengthening the instru- 

 ment and making it with a clasp in the middle, so that it could 

 be folded together when out of use. 



Fig. 17. Brandis' Hypsometer and Clinometer. 

 (The front lid removed, so as to show the wheel.) 



It is evident that, instead of using a staff 4 yards long, one 

 of, say, 2 yards can be used. In that case the height read off 

 on the instrument must be divided by 2. s 



The instrument works well up to 25, or at the outside up to 

 heights of 30 yards ; for higher trees it cannot be recommended 

 in its present shape. 



Brandis' Instrument* (Fig. 17). This instrument is based 

 on the trigonometrical method of height measuring. It con- 

 sists of a tube with an objective o at one end and an eye-piece, 

 e, in the shape of a horizontal slit, at the other. Attached 

 to this tube is a wheel, which is weighted on one side and 

 swings between two pivots, so that it always maintains the 



* To be obtained from Herr Max Wolz, Mechaniker, Bonn, Germany. 



