EFFECT OF GROUND PERMEABILITY 479 



The curves show the effect of m = 1-7 on the mutual impedance 

 between two parrallel ground return circuits with the wires lying on 

 the ground. The dashed portions of the curves were not computed. 



Appendix I 



Equations (4), (7) and (17) substituted into (16) give 



E.Cv, y) = £,(.v, 0) - '"j[''[ ,4V-y)' 



/•« 

 + (/)(r) cos XT-e-^\l 



Jo 



= E,{x, 0) + /CO i 4>{t) cos .Tr(f-^' - 1) — 

 Jo ^ 



+ 7 CO 7 log 



7 ^^ 



T 



x^ + (h - yY _ dV 

 X^ + //2 dz 



+ M7" 



..-, C^ M^" COS XT J 



Jo Vt- + ia 



Jo -yjT^ -f ia + yur ''" 



x2 + (//.- 3^)2 aF 



+ icci log 



pte 



x2 + h^ 



Jo V^ 



-(.ft + V)T 



Ho:! I , COS xtcIt 



+ 7a -|- /XT 



J""" . /h , N h X COS .rr , 







. ^, .1-2 + (// - yY dV 



+ 7co/ log ^ — ; — 7T ^ 



^ x- 4- //2 dz 



= — 74co/ I , COS XTCIT 



Jo VP 



+ ta -\- yur 



X-2+ (// - yY dV 



+ 7coi log -^—j — 77 — ^ 75 — ^— • 



x^ + (// + v)^ dz 



Appendix II 

 The succeeding analysis has been considerably shortened by writing 



In — I 



