88 



Transactions of the Royal Canadian Institute 



If we assume the inductance of the sHde to be evenly distributed, 

 we may write the impedances of the two parts as R {l-\-iq), Ri(l -\-iq), 

 where q is some constant. 



Also, the impedances of the capacity arms are l/«^(C+<z), l/«/>(C' + 6) 



When balance is obtained, we have, 



R(l+tg) ip{C'-{-b) 

 f R' {\-^iq)~ip (C+o) 



that is, R/R' = (C+&)/(C+a). 



If the lead capacity a is negligible, this reduces to 



R A/47ra;+6 

 R'"" A/4x^ 

 or R/R'=d/x+47rJ6/A. 



Thus, there is a straight line relation between R/R' and 1/x. The 

 1/x intercept is —4 &/A, a quantity independent of d. Thus the curves 

 connecting R/R' and Xjx for various values of d should cut the axis 

 of Xjx at the same point. 



Further, if we call this intercept —I, we can easily calculate the lead 

 capacity from the relation fe = AI/47r. The value of h obtained should 

 be independent of A. 



Comparison of the graphs of Figs. 4a and 4b, obtained with plates 

 of different areas A shows that these conditions are very nearly fulfilled. 



s , 10 



Value of '/x Ccm-'J. 



