242 



THE MEASUREMENT OF STANDING TREES 



horizontal scale at base and a vertical scale ad intersecting the scale 

 at base at right angles, at a point to permit this horizontal scale to extend 

 in both directions as in the Faustmann Hypsometer. Both scales are 

 marked off in the number of equal units or graduations desired, to cor- 

 respond with the distance from the tree at which the hypsometer is to 

 be used. A plumb-bob is suspended from point a, and the heights above 

 and below the eye read as usual. If but one fixed distance is desired 

 this is represented by a scale reproduced on the line at base of card. 



Fig. 49. — The Weise hypsometer. 



This board may be graduated to read at lesser distances from the 

 tree, by placing other horizontal scales upon the board intersecting 

 the vertical or " distance " scale ad at the point below the apex a, 

 representing the distances desired, and graduating these horizontal 

 lines to the same scale as the base. This home-made hypsometer is 

 described in Farmers' Bulletin 715, U. S. Dept. of Agriculture, 1916, 

 p. 18. 



The original instrument from which this type of hypsometer was 

 derived is known as the Winkler hypsometer, shown in Fig. 50. This 

 instrument is also used as a dendrometer (§ 200). 



