VOLUME I

Fundamental principles By K. B. Miller and S. G. McMeen[A]

Acoustics—­Characteristics of Sound—­Loudness—­Pitch—­Vibration of
Diaphragms—­Timbre—­Human Voice—­Human Ear—­Speech—­Magneto
Telephones—­Loose-Contact Principle—­Induction Coils—­Simple Telephone
Circuit—­Capacity—­Telephone Currents—­Audible and Visible
Signals—­Telephone Lines—­Conductors—­Inductance—­Insulation

Substation equipment By K. B. Miller and S. G. McMeen

Transmitters—­Variable Resistance—­Materials—­Single and Multiple
Electrodes—­Solid-Back Transmitter—­Types of
Transmitters—­Electrodes—­Packing—­Acousticon Transmitter—­Switchboard
Transmitter—­Receivers—­Types of Receivers—­Operator’s
Receiver—­Primary Cells—­Series and Multiple Connections—­Types of
Primary Cells—­Magneto Signaling Apparatus—­Battery Bell—­Magneto
Bell—­Magneto Generator—­Armature—­Automatic Shunt—­Polarized
Ringer—­Hook Switch—­Electromagnets—­Impedance, Induction, and
Repeating Coils—­Non-Inductive Resistance
Devices—­Differentially-Wound Unit—­Condensers—­Materials—­Current
Supply to Transmitters—­Local Battery—­Common Battery—­Diagrams of
Common-Battery Systems—­Telephone Sets:  Magneto, Series and Bridging,
Common-Battery

Party-line systems By K. B. Miller and S. G. McMeen

Non-Selective Party-Line Systems—­Series and Bridging—­Signal Code—­Selective Party-Line Systems:  Polarity, Harmonic, Step-by-Step, and Broken-Line—­Lock-Out Party-Line Systems:  Poole, Step-by-Step, and Broken-Line

Protection By K. B. Miller and S. G. McMeen

Electrical Hazards—­High Potentials—­Air-Gap Arrester—­Discharge across Gaps—­Types of Arrester—­Vacuum Arrester—­Strong Currents—­Fuses—­Sneak Currents—­Line Protection—­Central-Office and Subscribers’ Station Protectors—­City Exchange Requirements—­Electrolysis

MANUAL SWITCHBOARDS By K. B. Miller and S. G. McMeen

The Telephone Exchange—­Subscribers’, Trunk, and Toll Lines—­Districts—­Switchboards—­Simple Magneto Switchboard—­Operation—­Commercial Types of Drops and Jacks—­Manual vs.  Automatic Restoration—­Switchboard Plugs and Cords—­Ringing and Listening Keys—­Operator’s Telephone Equipment—­Circuits of Complete Switchboard—­Night-Alarm Circuits—­Grounded and Metallic Circuit Line—­Cord Circuit—­Switchboard Assembly

REVIEW QUESTIONS

INDEX

[Footnote A:  For professional standing of authors, see list of Authors and Collaborators at front of volume.]

[Illustration:  OLD BRANCH-TERMINAL MULTIPLE BOARD, PARIS, FRANCE]

TELEPHONY

INTRODUCTION