234 



GRAVITATIONAL METHODS 



[Chap. 7 



Fia. 7-82. Terrain and interpretation diagram 67. 



HORIZON 



Fig. 7-83. Terrain and interpretation diagram CI. 



There are a number of other terrain correction methods in addition to 

 those described above which also make use of vertical diagrams. In 

 Haalck's method/"'* for instance, diagrams are prepared for given azi- 

 muths as in the author's methods. However, the mass elements are 



i"Zeit. Geophys., 4, 161-178 (1928). 



