P
Phantom circuit 321
Pilot signals 17
Plug-seat switch 38
Pole changers for harmonic ringing 231
Power plants 227
auxiliary signaling currents 233
currents employed 227
alternating current 227
direct current 227
operator's transmitter supply 228
power plant circuit 248
power switchboard 246
meters 246
protective devices 248
switches 246
primary sources 234
charging from direct-current mains 234
charging dynamos 235
mercury-arc rectifiers 236
rotary converters 234
provision against breakdown 237
capacity of power units 238
duplicate charging machines 238
duplicate primary sources 238
duplicate ringing machines 238
ringing-current supply 229
magneto generators 229
pole changers 229
ringing dynamos 232
storage battery 239
initial charge 241
installation 240
low cells 244
operation 242
overcharge 243
pilot cell 243
regular charge 244
replacing batteries 245
sediment 245
types 227
common-battery systems 228
magneto systems 228
Power switchboard 246
Private-branch exchanges 271
with automatic offices 278
secrecy 279
battery supply 279
circuits, key-type board 276
definitions 271
desirable features 281
functions of the private-branch exchange operator 272
marking of apparatus 281
private-branch switchboards 273
common-battery type 273
cord type 275
key type 275
magneto type 273
ringing current 280
supervision of private-branch connections 277
R
Relays 28
Rotary connector 202
S
Selecting switches 175
Selector 175
Simplex circuits 324
Storage battery 239
Storage cell 240
Stromberg-Carlson multiple board 96
Strowger automatic system 143
Subscribers' board 259-261
Switchboard assembly 31
T
Table
automanual system time data 225
automatic systems, messages per trunk in 305
calling rates 302
long-distance groups, messages per trunk in 305
manual system, messages per trunk in 304
out-trunking, effect of, on operator's capacity 303
subscribers' waiting time 226
Telephone traffic 298
importance of traffic study 300
methods of traffic study 301
observation of service 308
quality of service 305
accuracy and promptness 307
answering time 306
busy and don't answer calls 307
courtesy and form 307
disconnecting time 306
enunciation 308
team work 308
rates of calling 300
representative traffic data 302
calling rates 302
operators' loads 302
toll traffic 304
trunk efficiency 303
trunking factor 303
traffic variations 298
busy hour ratio 299
unit of traffic 298
Telephone train dispatching 333
advantages 335
apparatus 338
Cummings-Wray selector 342
dispatcher's transmitter 343
Gill selector 341
portable train sets 345
siding telephones 345
waystation telephones 344
Western Electric selector 338
blocking sets 355
causes of its introduction 334
Cummings-Wray circuits 350
on electric railways 356
Gill circuits 349
railroad conditions 337
rapid growth 333
test boards 353
transmitting orders 337
waystation circuits 348
Western Electric circuits 347
Telephone train-dispatching circuit
Cummings-Wray 350
Gill 349
waystation 348
Western Electric 347
Test boards 353
Transfer switchboard 34
field of usefulness 41
handling transfers 38
limitations 40
plug-seat switch 38
transfer lines 35
jack-ended trunk 35
plug-ended trunk 37
Trunking in multi-office systems 109
classification 112
one-way trunks 103
two-way trunks 112
Kellogg trunk circuits 125
necessity for exchanges 109
Western Electric trunk circuits 116
W
Warner pole changer 230
Waystation telephones 344
Western Electric
mechanical signal 27
selector 338
trunk circuits 116
Spelling variants where it wasn't possible to determine the author's intent were left as is. These include: "clockwork" and "clock-work;" "doorkeeper" and "door-keeper;" "interrelation" and "inter-relation;" "multicyclic" and "multi-cyclic;" "redesign" and "re-design," along with derivatives.
Added closing double quote in Steinmetz entry in list of authorities: "Theoretical Elements of Electrical Engineering."
Changed "switch-hook" to "switch hook" on page 88: "the subscriber's switch hook."
Page 107 says there is room for 300 banks of 100 multiple jacks, but then says this allows for 3,000 multiple jacks in all, rather than 30,000. Based on the figure, 300 banks should be 30 banks, which would correct the arithmetic. However, I did not change this.
Changed "bi-paths" to "by-paths" on page 185: "circuits or by-paths."
Changed "appararus" to "apparatus" on page 209: "The sectional apparatus."
Changed "two number" to "two-number" on page 312: "the two-number calls are ticketed."
On page 333, a paragraph begins with "It has been only within the past three few." Perhaps the author meant "It has been only within the past three years" or "It has been only within the past few years." But since I didn't know, I left is as is.
Changed "them ain" to "the main" on page 333: "on the main line."
Changed "weatherproof" to "weather-proof" on page 357: "iron weather-proof sets."
Changed "interoffice" to "inter-office" three times on page 364, to match the spelling in the body of the document: "meant by inter-office trunking;" "inter-office connection system;" "of the inter-office connection."
Changed "break-down" to "breakdown" on page 367: "provision against breakdown."
Changed "way-station" to "waystation" twice on page 372: "with a waystation set;" and "a waystation on a block wire."
Changed "way stations" to "waystations" on page 375, in the entry for Long-distance switching.
Each page of the Index repeated this text: "Note.—For page numbers see foot of pages." They were removed.