VOLUME XV OCTOBER, 1936 number 4 



THE BELL SYSTEM 



TECHNICAL JOURNAL 



DEVOTED TO THE SCIENTIFIC AND ENGINEERING ASPECTS 

 OF ELECTRICAL COMMUNICATION 



Microchemical and Special Methods of Analysis in Communi- 

 cation Research — Beverly L. Clarke and H. W. Hermance 483 



Switchboards and Signaling Facilities of the Telet3^ewriter 

 Exchange System — 



A. D. Knowlton, G. A. Locke and F. J. Singer 504 



A Transmission System for Teletj^ewriter Exchange Service — 



R. E. Pierce and E. W. Bemis 529 



A New Telephotograph System— F. W. Reynolds .... 549 



Equivalent Networks of Negative-Grid Vacuum Tubes at 



Ultra-High Frequencies— f. B. Llewellyn 575 



Forces of Oblique Winds on Telephone Wires — J. A. Carr 587 



Corrosion of Metals — II. Lead and Lead-Alloy Cable Sheath- 

 ing — R. M. Burns 603 



Technical Digest — 



Reduction of Airplane Noise and Vibration — 



C. J. Spain, D. P. Loye and E. W. Templin 626 



Abstracts of Technical Papers 628 



Contributors to this Issue 633 



AMERICAN TELEPHONE AND TELEGRAPH COMPANY 



NEW YORK 



50c per Copy $L50 per Year 



