50 



BELL SYSTEM TECHNICAL JOURNAL 



pair except the pole pairs is reduced to 23 centimeters and the phan- 

 toms on these wires are abandoned. Type "C" systems can then be 

 used on all of the pairs with this spacing. The result as indicated on 

 the diagram is that a 40 wire toll line provides 70 telephone and 80 

 telegraph circuits. 



3-C 

 T T 



3-C 





3-C 



~ ~ T T<^ T 88 T y^ T 



3-C 



8v8 



3-C 

 T T 



T T 



3-C 



T T 



3-C 



3-C 



T T 



3-C 



3-C 



T T 



T T 



.fivs i om& i ava 



"^ ^^, i "^^ ° ."^1 ,<^ T 



3-C 



ML 



T T 



vv^ 



Fig. 41 — Pole Line Configuration, non-phantomed construction, 

 8 inch spacing between wires of non-pole pairs. 



Symbol 

 V 



PH 

 3-C 

 T 

 BH 



Toll Cables 



In spite of the great extension in the use of open wire circuits 

 brought about through the application of carrier systems, as indicated 

 above, it would be extremely difficult with the present rapid growth 

 in toll business to provide by open wire toll lines the large numbers 

 of telephone toll circuits now required on many routes. It is ver}- 

 fortunate that the development of means for providing satisfactory 

 long distance circuits through telephone cables has matured in time 

 to enable this method of construction to be widely used to meet the 



