NEM' YORK-CUICAGO CABLE 



65 



existing pole lines are fully loaded, and where estimated future circuit 

 requirements are of considerable magnitude, it is obvious that different 

 methods of providing facilities, if available, must sooner or later 

 be given serious consideration. The conditions between Phila- 

 delphia and Pittsburgh and in general along all of the cable routes 

 shown on Fig. 1 are now, or are expected within a few years to be, 

 such as to make the use of some type of construction other than aerial 

 wire desirable for most of the circuits. 



After careful studies of the circuit requirements for future periods 



Fig. 4 — Section of New York-Boston Main Line Showing Wires Heavily Loaded with 



Ice. November 28. 1921 



and of the methods available for providing long-distance telephone 

 facilities, which in general are aerial wire and cable, it has been decided 

 that for relief in these sections the cable method will give the best 

 and most economical results. Long underground cables, as is well- 

 known, have been in operation for many years between Boston, New 

 York, Philadelphia, Baltimore and Washington, Chicago and Mil- 

 waukee and in other sections. However, the type of cable and asso- 

 ciated apparatus which is now being used in the development of the 

 more comprehensive plan is quite different from that originally used 

 between Boston and Washington and in the other sections, particu- 

 larly in the use of copper conductors of a smaller gage combined 

 with improved loading coils, the vacuum tube telephone repeater 



