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BELL SYSTEM TECHNICAL JOURNAL 



Pcos pt + Q COS qt 



Fig. 2 — Tracing of a subsidiary loop according to Madelung. 



denoting by hr the value of h at h' = 0, which is 



hr = 2^ - P + Q cos qr. (37) 



The upper branch of the major loop as a function of h (not //) is 



Br= (mo + 2 I'll)}!. + v{IP - h') (38) 



with 



H= P + Q. 



The expansion (36) is now found to be 



B' = Uo + 2p12(P - A) + (2(1 - cosgr)]]// - W//1 (39) 



Equations (34), (35), and (39) define the induction in terms of h' over 

 an entire high-frequency cycle; the first is valid for — tt < p\ < 0, 

 the second for < />X < tt — pA, and the last for ir — pA < p\ < ir. 



