[CHAPTER XXXII]—Currents Employed—Types—Operator's Transmitter Supply—Ringing-Current Supply—Auxiliary Signaling Current—Primary Sources—Duplicate Apparatus—Storage Batteries—Power Switchboards—Circuits

[CHAPTER XXXIII]—Central-Office Building—Arrangement of Apparatus—Manual Offices—Automatic Offices

Special Service Features By K. B. Miller and S. G. McMeen Page 271

[CHAPTER XXXIV]—Private-Branch Exchanges—Switchboards—Supervision—With Automatic Offices—Battery Supply—Ringing Current

[CHAPTER XXXV]—Inter-Communicating Systems—Magneto System—Common-Battery Systems—Types

[CHAPTER XXXVI]—Long-Distance Switching—Operator's Orders—Trunking—Way Stations

[CHAPTER XXXVII]—Traffic

[CHAPTER XXXVIII]—Measured Service—Charging—Rates—Toll Service—Local Service

Telegraph and Railway Work By K. B. Miller and S. G. McMeen Page 321

[CHAPTER XXXIX]—Phantom, Simplex, and Composite Circuits—Ringing—Railway Composite