The Bell System Technical Journal 



April, 1926 



Development and Application of Loading for 

 Telephone Circuits ' 



By THOMAS SHAW and WILLIAM FONDILLER 



Synopsis: A review of the art of loading telephone circuits as practised 

 in the United States. The introductory section briefly reviews the theory 

 of coil loading, and summarizes the principal characteristics of the first 



CORRECTION SLIP FOR ISSUE OF JANUARY, 1926 

 Page 172: Equation should read 



Page 177: Equations (9), (10), (11) and (13) should read 



ei = 27r / Vo+/sin r {t-d,/V)]dt, (9) 



Jo 



e2 = 27r /'[Fo+Jsin r{t-d2/V)]dL (10) 



Ae = ei-G2 = 27r /VoC?/ + 2x f'f sin r (t-di/V) dt 

 Jo Jo 



-27r / Fo dt - 2Tr I J sin r (t-d^/V) dt, (11) 



Jo Jo 



27rf 

 A9= — - [(cos rf—1) (cos r do/ V— cos r di/V) 

 r 



+ sin rt (sin r do/ V- sin r di/V)]. (13) 



Delete (12) 



standing importance have been made in the characteristics of the load- 



1 Presented at the Midwinter Convention of the A. L E. E., New York, N. Y., 

 February 9, 1926. 



2 "Commercial Loading of Telephone Circuits in the Bell System," B. Gherardi, 

 Trans. A. L E. E., Vol. 30, 1911, p. 1743. 



221 



