VOLUME XI JANUARY, I93t2'. .". NUMBER 1 



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THE BELL SYSTEM 



TECHNICAL JOURNAL 



DEVOTED TO THE SCIENTIHC AND ENGINEERING ASPECTS 

 OF ELECTRICAL COMMUNICATION 



The Cathode Ray Oscillograph — 7. B. Johnson ... 1 



The Operation of Vacutun Tubes as Class B and Class 



C Amplifiers— C. E. Fay 28 



The Time Factor in Telephone Transmission — 



O. B, Blackwell 53 



Constant Frequency Oscillators — F. B, Llewellyn . . 67 



Some Physical Properties of Wiping Solders — 



D. A. McLean, R. L. Peek, Jr., and E. E. Schumacher 101 



Regeneration Theory — H. Nyquist 126 



Contemporary Advances in Physics, XXni — Data and 



Nature of Cosmic Rays — Karl K. Darrow . . o 148 



Abstracts of Technical Papers 185 



Contributors to this Issue 195 



AMERICAN TELEPHONE AND TELEGRAPH COMPANY 



NEW YORK 



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