768 THE BELL SYSTEM TECHNICAL JOURNAL, JULY 1951 



Choice of Gauge in London's Approach to the Theory of Superconductivity, 

 J. Bardeen^ Letter to the editor. Phys. Rev., v. 81, pp. 469-470, Feb. 1, 

 1951. 



Ferromagnetism. R. M. Bozorth^ N. F., Van Nostrand, 1951. 968 p. 

 (Bell Telephone Laboratories Series). 



Community Dial Office Equipment* A. Burkett^ Elec. Engg., v. 70, pp. 

 231-234, Mar., 1951. 



Abstract — Equipment for community dial offices which serve small or 

 sparsely settled communities is described in this article. The discussion 

 covers service features, equipment features, and maintenance facilities. 



Operational Study of a Highway Mobile Telephone System* L. A. Dorff^ 

 Elec. Engg., v. 70, pp. 236-241, Mar., 1951. 



Abstract — The problem of interference of nearby stations was one of 

 the greatest problems which had to be overcome to permit the satisfactory 

 use of mobile telephone service. This article tells of a study made of the 

 interference encountered on one highway mobile telephone system and the 

 measures made to counteract it. 



A Precision Decade Oscillator for 20 Cycles to 200 Kilocycles. C. 

 M. Edwards^. I.R.E., Proc, v. 39, pp. 277-278, Mar., 1951. 



The Control Chart as a Tool for Analyzing Experimental Data.* E. B. 

 Ferrell'. I.R.E., Proc, v. 39, pp. 132-137, Feb., 1951. 



Abstract — The statistical methods that have been developed for use in 

 quality control are a powerful tool in the interpretation of laboratory ex- 

 periments where only a small amount of data is available. An understanding 

 of these methods also permits more logical planning of experiments and 

 improves what we might call "the efficiency of experimentation." One of the 

 simplest and most broadly useful of these tools is the control chart. It is easy 

 to understand and use and in many cases can take the place of more labori- 

 ous and complicated methods of analysis. 



Crystalline Magnetic Anisotropy in Zinc Manganese Ferrite. J. K. Galt^, 

 W. A. Yager^, J. P. Remeika^ and F. R. Merritt^ Letter to the editor. 

 References. Phys. Rev., v. 81, p. 470, Feb. 1, 1951. 



A Submarine Telephone Cable With Submerged Repeaters.* J. J. Gilbert^. 

 Elec. Engg., v. 70, pp. 248-253, Mar., 1951. 



Abstract — Repeaters designed for long life are incorporated in the cable 

 structure and are laid as part of the cable of the recently installed Key 

 West-Havana submarine telephone cable system. To eliminate the need for 

 servicing the repeaters, the components were designed so that parts would 

 not have to be replaced for 20 years or more. 



* A reprint of this article may be obtained on request. 



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