238 



for gradients and 



GRAVITATIONAL METHODS 



COS 2a J dp 

 da — 



[Chap. 7 



(sin 2a) 



for curvatures, apply. Hence, the substitutions R = 1/p for gradients 



and R = \/2/p for curvatures, $ = sin a, cos a for gradients and $ = 



sin 2a , cos 2a . ^ i j 



— - — and — ^ — for curvatures may be made. 



i2i4S67S9lO 



Fig. 7-86. Scale distortion for curvatures in Below-Jung's planimeter terrain correc- 

 tion (after Jung). 



Distortions of diagrams may be avoided by the use of specially con- 

 structed integraphs. The Ask^nia Werke have constructed a special 

 integraph^"* for the evaluation of gravity and torsion anomalies which 

 may also be applied to calculations of terrain effects. If the topography 

 around the station lists been represented by lines of equal elevation angle, 



I / COS OL d/D 



the terrain effects which contain the double integrals \ \ , . ^ da — 



J J (sm a) p 



, . ^ . da — ior curvatures may be written 

 (sm 2a) p 



for gradients and / / 



'« F. Kaaelitz, Zeit. Geophys., 8(3/4), 191 (1932). See also p. 269. 



