580 



BELL SYSTEM TECHNICAL JOURNAL 



POWER WIRE 



A- LOW RESISTIVITY EARTH 



POWER WIRE 



■^ 



/ / I ■--.. 



/ 

 / 



B-HIGH RESISTIVITY EARTH 

 Fig. 3 — Current distribution in earth of different resistivities. 



POWER LINE 



TO AMPLIFIER 

 AND METER 



Fig. 4 — Demonstration of effects of dei)th of return current in earth. 



