of the communications between the United States Capitol and the 

 rest of the nation. Upon the success of the experiments described 

 above, it was decided to complete an underground cable route con- 

 necting Washington with Baltimore, Philadelphia, and New York, 

 using large gauge conductors, the phantoming principle which had 

 just been successfully demonstrated, and new systems of loading 

 designed specifically for the new cable. The project was completed 

 in 1912 and in 1913 this high grade cable route was extended to 

 Boston, through New Haven, Hartford and Providence. 



Possibilities and Problems Associated with the 

 Use of the Telephone Repeater 



The developments discussed above had done a great deal to extend 

 the range of telephone service making possible good commercial 

 service between the Atlantic Seaboard and Chicago and a service of a 

 kind as far west as Denver and providing a storm-proof cable route 

 connecting Washington and Boston and the intermediate cities of the 

 Atlantic Seaboard. By 1912, however, it was apparent that in 

 addition to pushing to the utmost the advantages to be gained from 

 the technique already developed, it would be necessary, if universal 

 service for the entire country were to be realized, to find satisfactory 

 means for amplifying the attenuated telephone currents on a long 

 telephone circuit so that after transmission over one section of line 

 they could be restored, in amplitude, transmitted into a second section, 

 and when again attenuated restored a second time and transmitted into 

 a third section of the line and so on, without undue distortion or change 

 in the structure of the voice currents. The device to accomplish this 

 is called a telephone repeater. The conclusion that improved repeaters 

 were required was reached after a careful analysis of all of the possible 

 means of achieving further extensions in the range of long distance 

 transmission and as a result the energies of the research forces of the 

 Bell System were to a greater extent than before directed to the devel- 

 opment of improved telephone repeaters and of circuits and methods 

 of line construction which would make possible their general use. 



One of the chief problems which confronted the engineers undertaking 

 the intensive telephone repeater development work beginning in 1912, 

 was the development of an amplifying element for a repeater which 

 could be used generally for telephone purposes. The telephone re- 

 peater was not new in the art at that time, since a repeater giving 

 beneficial results had been invented by H. E. Shreeve of the Bell 

 System and first used successfully on a circuit between Amesbury, 

 Massachusetts and Boston in 1904. The Shreeve repeater took ad- 



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