VOLUME XIV OCTOBER, 1935 number 4 



THE BELL SYSTEM 



TECHNICAL JOURNAL 



DEVOTED TO THE SCIENTITIC AND ENGINEERING ASPECTS 

 OF ELECTRICAL COMMUNICATION 



Dr. George A. Campbell— /''. B. Jewett 553 



Dr. Campbell's Memoranda of 1907 and 1912 558 



Some Aspects of Low-Frequency Induction Between Power and 

 Telephone Circuits — H. R. Huntley and E, J. O'Connell 573 



Circulating Currents and Singing on Two-Wire Cable Circuits — 



L. G. Abraham 600 

 Operation of Ultra-High-Frequency Vacuum Tubes — 



F. B. Llewellyn 632 

 Further Extensions of Theory of Multi-Electrode Vacuum Tube 



Circuits — S. A. Levin and L. C. Peterson 666 



Transatlantic Long- Wave Transmission — 



Austin Bailey and H. M. Thomson 680 

 Technical Digests — 



1. Superiorities of Lead- Calcium Alloys for Storage Battery Con- 



struction — H. E. Haring, U. B. Thomas^ E. E. Schumacher 

 and G. S. Phipps 699 



2. Marine Radio Telephone Service for Boston Harbor— 



F. A. Gifford and R. B. Meader 702 



3. Harbor Craft Ship-to-Shore Radio Telephone Service in Puget 



Sound Aiea—E. B. Hansen 708 



4. Ship Sets for Harbor Ship-to-Shore Service— H. N. Willets . . 713 



5. An Electromechanical Representation of a Piezoelectric 



Crystal— IT. P. Mason 718 



Abstracts of Technical Papers 724 



Contributors to this Issue 728 



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