ord circuit
battery supply 20
complete circuit 21
supervisory signals 21

Cord-rack connectors 66

Cummings-Wray selector 342

D

Dean multiple board 93

Dispatchers' keys 339

Dispatching on electric railways 356

G

Gill selector 341

H

Housing central-office equipment 249
arrangement of apparatus in small manual offices 252
combined main and intermediate frames 253
floor plans for 252
types of line circuits 255
automatic offices 267
typical automatic office 270
central-office building 249
fire hazard 249
provision for cable runways 251
provision for employes 251
size of building 250
strength of building 250
large manual office 256

I

Intercommunicating systems 282
common-battery systems 283
Kellogg plug type 284
Kellogg push-button type 285
Monarch system 287
Western Electric system 285
definition 282
limitations 282
for private-branch exchanges 290
simple magneto system 282

J

Jacks 30

K

Kellogg mechanical signal 28

Kellogg trunk circuits 125

Kellogg two-wire multiple board 84

Keyboard wiring 67

L

Lamp mounting 25

Lamps 24

Line signals 14
direct-line lamp 14
direct-line lamp with ballast 15
line lamp with relay 17
pilot signals 17

Line switch 163

Long-distance switching 293
definitions 293
center-checking 297
operators' orders 294
by call circuits 294
by telegraph 294
particular party calls 295
switching through local board 293
ticket passing 296
trunking 295
high-voltage toll trunks 295
through ringing 295
two-number calls 294
use of repeating coil 293
waystations 297

Lorimer automatic system 144, 205
central-office apparatus 208
connective division 210
sectional apparatus 209
switches 213
interconnector 214
interconnector selector 214
primary connector 213
rotary switch 213
secondary connector 214
signal transmitter controller 214
operation 215
subscriber's station equipment 206

M

Magneto multiple switchboard 53
branch-terminal multiple board 58
arrangement of apparatus 61
magnet windings 61
operation 60
field of utility 53
modern magneto multiple board 63
assembly 66
cord circuit 64
test 62

Magneto multiple switchboard
series-multiple board 54
defects 57
operation 56

Measured se