Abstracts of Recent Technical Papers from Bell 

 System Sources 



Loading for Telephone Cable Circuits} D. W. Whitney. This 

 paper summarizes the principal characteristics of the loaded telephone 

 line and discusses the major improvements in loading. Up to 1900 

 there was a general avoidance of the use of cable in the toll telephone 

 plant, due to the high attenuation and distortion of speech currents not 

 experienced in open wire lines. By the use of the loading coil and the 

 telephone repeater, a network of toll cables has grown very rapidly 

 which now connects the large population centers of the Atlantic 

 seaboard and the upper Mississippi Valley region. 



Electric Annealing of Magnetic Materials for Telephone Apparatus.- 

 W. A. TiMM. This paper briefly describes the annealing equipment 

 used by the Western Electric Company prior to 1909 and some years 

 afterward at the Hawthorne plant, in contrast to the more recently 

 installed electrical equipment. 



The Problem of Secondary Metals in World Affairs } F. W. Willard. 

 Preliminary to the discussion of the secondary metal industry, the 

 author gives a brief statistical survey of the rate of depletion of the 

 world's primary metal resources along with a study of metal production 

 in the United States. 



The rapid rate of exhaustion of known resources is emphasized. 

 Graphs also show the relation of prices and production of copper and 

 lead in the United States over a period of 40 years. 



Each important economic metal is discussed briefly showing how 

 its present commercial uses affect its return through the secondary 

 market. Attention is directed to the degradation of metals in use, 

 forever eliminating them for re-use. Platinum, though not generally 

 classified among economic metals, is treated briefly because of its key 

 importance in certain industries. The seriousness of the present trend 

 of using platinum in jewelry is indicated. 



The growing importance of the secondary metal industry is shown 

 graphically and briefly discussed, leading to an emphasis of the need 



^ To be published in the Proceedings of the Telephone and Telegraph Section of 

 the American Railway Association. 



- Trans. American Soc. Steel Treat., p. 782, Nov. 1926. 



^Industrial and Eng. Chemistry, p. 1178, Nov. 1926. Presented at the Round 

 Table Conference on the role of chemistry in the world's affairs at Williamstown, 

 Mass., Aug. 1926. 



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