CONQUEST OF DISTANCE BY WIRE TELEPHONY 363 



long distance facilities, that a substantial amount of engineering information 

 regarding them was made available to the field in conferences, and in routine 

 correspondence on current engineering projects, in advance of the comple- 

 tion of the development work. A coordinated quantitative statement was 

 given in General Engineering Circular No. 107, "Aerial Loading and Duplex 

 Cable," which was issued on August 19, 1910, in advance of the completion 

 of the trial installations of open-wire phantom loading and loaded duplex 

 cable, so as to assure that the new developments would be fully taken into 

 account in preparing the 1911 Provisional Estimates and in planning the 

 1911 construction program. 



In the open-wire plant, the new loading and phantoming developments 

 had extensive application even before the end of 1910. The following 

 pertinent quotation is from a paper, "Long Distance Telephony in America," 

 read by John J. Carty at the second international conference of European 

 Telephone & Telegraph Administrations, Paris, Sept. 1910.^ 



"Aerial Loading: At the present time there are about 52,000 miles of loaded 

 No. 12 NBSG Circuit in the United States and about 1000 miles of No. 8 BWG 

 loaded circuit. There are at present under construction, or intended for com- 

 pletion by January 1, 1911, about 17,000 miles of No. 12 NBSG loaded circuit, 

 and about 13,000 miles of No. 8 BWG loaded circuit. Of this latter, about 

 3800 miles, namely four circuits from New York to Chicago will be arranged 

 for phantom working, ..." 



The Carty paper also was prepared in advance of the completion of the 

 development work. In general it could be considered a European edition 

 of G.E.C. 107, but it went beyond the latter in mentioning some high 

 spots of certain spectacular new engineering projects, namely the New York- 

 Denver line and Boston- Washington underground cable. 



In the cable plant, also, there was accelerating activity in the installation 

 of loaded duplex entrance cables, beginning in the latter part of 1910. 

 This was especially desirable in connection with open-wire phantom lines 

 that were used also for composite telegraph service, due to complications 

 otherwise involved in carrying the telegraph circuits through the entrance 

 cables. The use of loaded quadded cable for toll cable facilities also started 

 quickly and expanded rapidly, the Boston- Washington project being the 

 outstanding initial commitment. 



From what has been said in the preceding paragraphs, however, it must 

 not be inferred that the development ended with the completion of the 

 initial commercial installations. As time went on, the service requirements 

 became increasingly severe, especially as regards crosstalk, and there has 

 been substantial continuous activity ever since in the laboratory, factory, 

 and field in the reduction of crosstalk unbalances in quadded cable, lines, 



^ The Carty paper also was published in the March 1911 issue of "Telephone Engineer" 

 (Chicago) . 



