588 



EXPLORATION GEOPHYSICS 



Fig. 366. — Power supply for deep electrical investigations. (Courtesy of Union Oil 

 Company of California.) 



Fig. 367. — Magnetometric method of conductive exploration. 

 H^, field surrounding the surface wire a; H^, field surrounding 

 the subsurface flow of current; 1 and 2, energizing electrodes. 

 (Courtesy of International Geophysics, Inc.) 



