THE BELL SYSTEM TECHNICAL JOURNAL 



Published quarterly by the 



American Telephone and Telegraph Company 



195 Broadway, New York, N. Y, 



— -»■» »■■■■« I 



EDITORS 

 R. W. King J. O. Perrine 



F. B. Jewett 

 O. E. Buckley 

 S. Bracken 



EDITORIAL BOARD 



M. R. Sullivan 

 A. B. Clark 

 M. J. KeUy 



O. B. Blackwell 

 H. S. Osborne 

 F. A. Cowan 



SUBSCRIPTIONS 



Subscriptions are accepted at $1.50 per year. Single copies are 50 cents each. 

 The foreign postage is 35 cents per year or 9 cents per copy. 



Copyright, 1943 

 American Telephone and Telegraph Company 



PRINTED IN U. S A. 



