*B. W. G. is the abbreviation for Birmingham wire gage--an English wire gage differing but slightly from the B. & S. gage. E. B. B. is the abbreviation for the "Extra Best Best" grade of iron wire. ††B. B. is the abbreviation for the "Best Best" grade of iron wire. Engineering telephone Examining partition interiors. Exchange intercommunicating system. Exchange, private branch... Exchange service. Exchange, small central. Exchange switchboard Extending radius of bell. Extension bells .32, 33 11, 12 117-118 ..vii ...95 179, 180 .183 198, 199 183-198 186-198 ...96 .61, 66 .215 ...157 .29, 30 59, 184, 185 G .35-37, 40-42, 89-90 .32, 33 29, 32 .33-35 H 161-163 ..93 104-108 .8, 9 .59, 184 Protection... Plugs.. Poles, telephone Positions in telephoning, proper and improper. Private branch exchange. Preservation of poles. Protective apparatus, wiring of.. 188, 190, 191, 192-194 .99-102 .85 183 143 .49, 121 57-60, 184 44, 45 Signaling apparatus, connections of...42, 168, 169, 178, 179 Series connection... Series party-line systems. Service, exchange.. Setting poles Shunt, automatic. |