DELL SYSTEM TECHNICAL JOURNAL 



July, 1931 



Some Physical Characteristics of Speech and Music — 



Harvey Fletcher 349 

 The Statistical Energy-Frequency Spectrum of Random Disturb- 

 ances — John R. Carson 374 



Bridge Methods for Locating Resistance Faults on Cable Wires — 



T. C. Henneherger and P. G. Edwards 382 

 Mutual Impedance of Grounded Wires Lying on the Surface of the 



Earth— i^onoW M. Foster 408 



Transients in Grounded Wires Lying on the Earth's Surface — 



John Riordan 420 

 Developments in the Manufacture of Lead-Covered Paper-In- 

 sulated Telephone Cable — John R. Shea 432 



Effect of Ground Permeability on Ground Return Circuits — 



W. Hozvard Wise 472 

 Negative Impedances and the Twin 21-Type Repeater — - 



George Crisson 485 

 New Standard Specifications for \\'ood Poles — R. L. Jones 514 



October, 1931 



The Interconnection of Telephone Systems — Graded Alultiples — 



R. I. Wilkinson 531 

 Moving Coil Telephone Receivers and Microphones — 



E. C. Wente and A. L. Thiiras 565 

 Some Developments in Common Frequency Broadcasting — 



G. D. Gillett S77 

 Application of Printing Telegraph to Long-Wave Radio Circuits — 



A. Bailey and T. A. McCann 601 

 Audible Frequency Ranges of INTusic, Speech and Noise — 



W. B. Snoiv 616 

 Contemporary Advances in Physics, XXII — Transmutation — 



Karl K. Darroiv 628 

 Developments in Short-Wave Directive Antennas — E. Bruce 656 



