638 



BELL SYSTEM TECHNICAL JOURNAL 



component are plotted, for conductivities of 2.5 X 10~^"' and 2.5 X 

 10~^^ (ahmhos per cm. cube). It will be seen that the experimental 

 values lie between these two curves, tending towards the former for 



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400 600 600 1000 1200 1400 



DISTANCE FROM ELECTRODE IN FEET 



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1800 



Fig. 10 — Cross Keys tests, 

 electrode. 



Mutual impedance gradient in vicinity of grounding 

 Comparison with calculated values. 



short distances from the electrode and towards the latter for long dis- 

 tances. As in the measurements previously described, the calculated 

 mutual reactance component is greater than the measured value, 



