Magnetic flux
Magnetization curves
Magnetizing force
Magneto bell
Magneto operator
Magneto signaling apparatus
  armature
  automatic shunt
  battery bell
  generator symbols
  magneto bell
  magneto generator
  method of signaling
  polarized ringer
  pulsating current
  ringer symbols
  theory
Magneto switchboard
  automatic restoration
    mechanical
      Dean type
      Kellogg type
      Monarch type
      Western Electric type
  circuits of complete switchboard
  code signaling
  commercial types of drops and jacks
    early drops
    jack mounting
    manual vs. automatic restoration
    methods of associating
    night alarm
    tubular drops
  component parts
    jacks and plugs
    keys
    line and cord equipments
    line signal
    operators’ equipment
  cord-circuit considerations
    double clearing-out type
    lamp-signal type
    non-ring through type
    series drop type
    simple bridging drop type
  definitions
  electrical restoration
  grounded and metallic-circuit lines
  mode of operation
  night-alarm circuits
  operation in detail
    clearing out
    essentials of operation
    normal condition of line
    operator answering
    operator calling
    subscriber calling
    subscribers conversing
    operator’s telephone equipment
    cut-in jack
  ringing and listening keys
    horizontal spring type
    party-line ringing keys
    self-indicating keys
    vertical spring type
  switchboard assembly
    functions of cabinet
    sectional switchboards
    upright type of switchboard
    wall type switchboard
  switchboard cords
    concentric conductors
    parallel tinsel conductors
    steel spiral conductors
  switchboard plugs
Magneto telephone
Magneto telephone sets
Mica card resistance
Mica slip fuse
Microtelephone set
Monarch drop and jack
Monarch receiver
Monarch transmitter
Multiple electrode
Mutual induction

N

Non-inductive resistance devices
  inductive neutrality
  provisions against heating
  temperature coefficient
  types
    differentially-wound unit
    iron wire ballast
    lamp filament
    mica card unit
Non-selective party-line systems
  bridging
  limitations
  series
  signal code

O

Open-circuit cells
Open-circuit impedance coil
Operator’s receiver

P