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VOLUME XX JULY, 1941 number 3 



THE BELL SYSTEM 



TECHNICAL JOURNAL 



DEVOTED TO THE SCIENTIFIC AND ENGINEERING ASPECTS 

 OF ELECTRICAL COMMUNICATION 



Industrial Mathematics — Thornton C. Fry 255 



The Transmission Characteristics of Toll Telephone 

 Cables at Carrier Frequencies— C. M. Hebbert 293 



Some Analyses of Wave Shapes Used in Harmonic 

 Producers—/'. R. Stansel 331 



Forces and Atoms: The World of the Physicist 



—Karl K. Darrow 340 



Abstracts of Technical Articles by Bell System Authors . 359 



Contributors to this Issue ^ . 364 



AMERICAN TELEPHONE AND TELEGRAPH COMPANY 



NEW YORK 



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