THE BELL SYSTEM 



Jecnnical ournal 



DEVOTED TO THE SC I EN TIKIC^^^ AND ENGINEERING 

 ASPECTS OF ELECTRICAL COMMUNICATION 



ADVISORY BOARD 



S. Bracken F. R. Kappel 



M. J. Kelly 



EDITORIAL COMMITTEE 



E. I. Green, Chairman 

 A. J. BuscH F. R. Lack 



W. H. DOHERTY W. H. NUNN 



G. D. Edwards H. L Romnes 



J. B. FisK H. V. Schmidt 



R. K. Honaman G. N. Thayer 



EDITORIAL STAFF 



J. D. Tebo, Editor M. E. Strieby, Managing Editor 



R. L. Shepherd, Production Editor 



INDEX 



VOLUME XXXII 



1953 



AMERICAN TELEPHONE AND TELEGRAPH COMPANY 



NEW YORK 



