TELEPHONES 



449 



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Fig. 343. 



Grounded private-line system 



consideration, because a telephone line without exchange 

 and toll-line facilities is like a railroad without terminal 

 facilities, if such a thing can be imagined, and will not be a 

 real success. 



Other things to be 

 determined through 

 negotiations with the 

 telephone company, 

 in case it is decided 

 to build a telephone 

 line, are those which 

 have a bearing on the 

 type of circuit to 



construct and equip, to the end that it may operate properly 

 with the apparatus, and under the operating method of the 

 telephone company. Some of those things are : (1) whether 

 central battery or local battery service should be arranged 

 for; (2) whether party-line service can be handled by the 

 telephone company, and, if it can, the kind of party line 

 service which is arranged for (a party line is one having 

 more than one telephone connected to it) ; (3) whether the 

 line or lines constructed should be metallic or "ground" 

 circuits (a metallic circuit is one consisting of two wires, 



and a ground circuit 

 is one consisting of a 

 single wire, the earth 

 being used as a 

 return) . 



Exchange service. 

 As to the first point, 

 some telephone com- 



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Fig. 344. Private lines using common return panies having central 



wire (McCiurg system) battery systems in 



town plan to operate all telephones within a certain distance 

 (ten miles from the central office) on a central battery basis. 

 Others offer either central or local battery connections, 



