INDEX

Acousticon transmitter [77]
Acoustics [19]
characteristics of sound [19]
loudness [20]
pitch [20]
timbre [21]
human ear [23]
human voice [22]
propagation of sound [19]
Air-gap vs. fuse arresters [304]
Amalgamated zincs [97]
Arrester separators [296]
Audible signals [39]
magneto bell [40]
telegraph sounder [39]
telephone receiver [43]
vibrating bell [40]
Automatic Electric Company
direct-current receiver [85]
transmitter [72]
Automatic shunt [124]

Bar electromagnet [148]
Battery bell [115]
Battery symbols [114]
Blake single electrode [64]
Brazed bell [130]
Broken-back ringer [280]
Broken-line method of selective signaling [261], [275]

Capacity reactance [55]
Carbon [31]
adaptability [31]
limitations [33]
preparation of [75]
superiority [32]
Carbon air-gap arrester [300]
Carbon-block arrester [296]
Carrying capacity of transmitter [76]
Central-office protectors [310]
Characteristics of sound [19]
loudness [20]
pitch [20]
timbre [21]
Chloride of silver cell [113]
Closed-circuit cells [106]
Closed-circuit impedance coil [164]
Common-battery telephone sets [217]
Condensers [178]
capacity [178]
charge [178]
conventional symbols [184]
definition of [180]
dielectric [180]
dielectric materials [182]
functions [184]
means for assorting current [185]
sizes [183]
theory [179]
Conductivity of conductors [49]
Conductors, conductivity of [49]
Conventional symbols [91]
Cook
air-gap arrester [298]
arrester [311]
arrester for magneto stations [313]
Crowfoot cell [106]
Current supply to transmitters [186]
common battery [188]
advantages [188]
bell substation arrangement [192]
bridging battery with impedance coils [194]
bridging battery with repeating coil [191]
current supply from distant point [204]
current supply over limbs of line in parallel [200]
Dean substation arrangement [197]
double battery with impedance coil [195]
Kellogg substation arrangement [198]
North Electric Company system [199]
series battery [189]
series substation arrangement [190]
Stromberg-Carlson system [198]
supply many lines from common source [202]
repeating coil [202]
retardation coil [204]
local battery [187]

Dean
drop and jack [344]
receiver [88]
wall telephone hook [137]
Desk stand hooks [138]
Kellogg [140]
Western Electric [138]
Dielectric [180]
Dielectric materials [182]
dry paper [182]
mica [182]
Differential electromagnet [151]
Direct-current receiver [84]
Drainage coils [315]

Electric lamp signal [44]
Electrical hazards [287]
Electrical reproduction of speech [24]
carbon [31]
conversion from sound waves to vibration of diaphragm [21]
conversion from vibration to voice currents [24]
conversion from voice currents to vibration [25]
cycle of conversion [26]
detrimental effects of capacity [36]
early conceptions [28]
electrostatic telephone [30]
induction coil [34]
limitations of magneto transmitter [29]
loose contact principle [27]
magneto telephone [26]
measurements of telephone currents [36]
variation of electrical pressure [30]
variation of resistance [30]
Electrical signals [39]
audible [39]
magneto-bell [40]
telegraph sounder [39]
telephone receiver [43]
vibrating bell [40]
visible [43]
electric lamp signal [44]
electromagnetic signal [43]
Electrodes [75]
arrangement of [63]
carbon preparation [75]
multiple [65]
single [64]
Electrolysis [315]
Electromagnetic method of measuring telephone currents [37]
Electromagnetic signal [43]
Electromagnets and inductive coils [143], [171]
conventional symbols [171]
differential electromagnet [151]
direction of armature motion [151]
direction of lines of force [146]
electromagnets [143]
low-resistance circuits [147]
horseshoe form [147]
iron-clad form [149]
special horseshoe form [150]
impedance coils [163]
kind of iron [164]
number of turns [103]
types
closed-circuit [164]
open-circuit [164]
toroidal [165]
induction coil [165]
current and voltage ratios [166]
design [166]
functions [166]
use and advantage [167]
magnet wire [153]
enamel [156]
silk and cotton insulation [155]
space utilization [156]
wire gauges [154]
magnetic flux [144]
magnetization curves [145]
magnetizing force [143]
mechanical details [152]
permeability [144]
reluctance [147]
repeating coil [168]
winding methods [158]
winding calculations [162]
winding data [159]
winding terminals [159]
Electrostatic capacity [50]
unit of [52]
Electrostatic telephone [30]
Enamel [156]

Five-bar generator [123]
Fuller cell [109]

Galvani [92]
Generator armature [119]
Generator cut-in switch [125]
Generator shunt switch [124]
Generator symbols [127]
Granular carbon [66]
Gravity cell [106]

Hand receivers [90]
Harmonic method of selective signaling [248]
advantages [258]
circuits [257]
in-tune system [253]
limitations [258]
principles [248]
tuning [250]
under-tune system [250]
Head receivers [90]
Heat coil [306]
Holtzer-Cabot arrester [300]
Hook switch [132]
automatic operation [133]
contact material [135]
design [134]
desk stand hooks [138]
Kellogg [140]
Western Electric [138]
purpose [132]
symbols [141]
wall telephone hooks [135]
Dean [137]
Kellogg [135]
Western Electric [136]
Horseshoe electromagnet [148]
Human ear [23]
Human voice [22]

Impedance coils [163]
kind of iron [164]
number of turns [163]
symbols of [165]
types
closed-circuit [164]
open-circuit [164]
toroidal [165]
Inductance vs. capacity [56]
Induction coil [34], [165]
current and voltage ratios [166]
design [166]
functions [166]
use and advantage [167]
Inductive neutrality [174]
Inductive reactance [55]
Insulation of conductors [56]
Introduction to telephony [11]
Iron-clad electromagnet [149]
Iron wire ballast [177]

Kellogg
air-gap arrester [299]
desk stand hook [140]
drop and jack [342]
receiver [83]
ringer [129]
transmitter [70]
wall telephone hook [135]

Lalande cell [112]
Lamp filament [176]
Le Clanché cell [99]
Lenz law [54]
Line signals [325]
Lines of force, direction of [146]
Loading coils [59]
Lock-out party-line systems [263]
broken-line method [275]
operation [282]
Poole system [264]
step-by-step system [267]
Loudness of sound [20]
Low-reluctance circuits [147]
horseshoe form [147]
iron-clad form [149]

Magnetic flux [144]
Magnetization curves [145]
Magnetizing force [143]
Magneto bell [40], [115]
Magneto operator [116]
Magneto signaling apparatus [115]
armature [119]
automatic shunt [124]
battery bell [115]
generator symbols [127]
magneto bell [115]
magneto generator [116]
method of signaling [115]
polarized ringer [128]
pulsating current [126]
ringer symbols [131]
theory [117]
Magneto switchboard [324]
automatic restoration [341]
mechanical [341]
Dean type [344]
Kellogg type [342]
Monarch type [345]
Western Electric type [313]
circuits of complete switchboard [356]
code signaling [346]
commercial types of drops and jacks [335]
early drops [335]
jack mounting [338]
manual vs. automatic restoration [340]
methods of associating [339]
night alarm [338]
tubular drops [336]
component parts [325]
jacks and plugs [325]
keys [327]
line and cord equipments [328]
line signal [325]
operators' equipment [328]
cord-circuit considerations [364]
double clearing-out type [368]
lamp-signal type [371]
non-ring through type [366]
series drop type [366]
simple bridging drop type [364]
definitions [324]
electrical restoration [347]
grounded and metallic-circuit lines [360]
mode of operation [324]
night-alarm circuits [358]
operation in detail [328]
clearing out [335]
essentials of operation [335]
normal condition of line [329]
operator answering [330]
operator calling [332]
subscriber calling [330]
subscribers conversing [333]
operator's telephone equipment [354]
cut-in jack [355]
ringing and listening keys [351]
horizontal spring type [351]
party-line ringing keys [353]
self-indicating keys [354]
vertical spring type [352]
switchboard assembly [373]
functions of cabinet [373]
sectional switchboards [384]
upright type of switchboard [376]
wall type switchboard [373]
switchboard cords [349]
concentric conductors [350]
parallel tinsel conductors [351]
steel spiral conductors [350]
switchboard plugs [348]
Magneto telephone [26]
Magneto telephone sets [209]
Mica card resistance [174]
Mica slip fuse [302]
Microtelephone set [223]
Monarch drop and jack [345]
Monarch receiver [86]
Monarch transmitter [73]
Multiple electrode [65]
Mutual induction [54]

Non-inductive resistance devices [172]
inductive neutrality [174]
provisions against heating [174]
temperature coefficient [172]
types
differentially-wound unit [175]
iron wire ballast [177]
lamp filament [176]
mica card unit [174]
Non-selective party-line systems [227]
bridging [230]
limitations [235]
series [229]
signal code [233]

Open-circuit cells [99]
Open-circuit impedance coil [164]
Operator's receiver [90]

Packing of transmitters [75]
Permeability [144]
Pitch [20]
Doppler's principle [20]
vibration of diaphragms [21]
Polarity method of selective signaling [239]
Polarization of cells [96]
Polarized ringer [41], [128]
brazed bell [130]
Kellogg [129]
Western Electric [128]
Poole lock-out system [264]
Primary cells [92]
conventional symbol [114]
series and multiple connections [98]
simple voltaic [92]
types of
closed-circuit [106]
Fuller [109]
gravity [106]
Lalande [112]
prevention of creeping [106]
setting up [108]
open-circuit [99]
Le Clanché [99]
standard [113]
chloride of silver [113]
Propagation of sound [19]
Protective means [294]
against high potentials [294]
air-gap arrester [295]
advantages of carbon [296]
commercial types [297]
continuous arcs [300]
discharge across gaps [295]
dust between carbons [296]
introduction of impedance [299]
metallic electrodes [300]
vacuum arresters [299]
against sneak currents [304]
heat coil [306]
sneak-current arresters [305]
against strong currents [301]
fuses [301]
enclosed [302]
mica [301]
proper functions [301]
central-office protectors [310]
self-soldering heat coils [310]
sneak-current and air-gap arrester [310]
city exchange requirements [314]
complete line protection [306]
electrolysis [315]
subscribers' station protectors [312]
ribbon fuses [313]
Pulsating-current commutator [127]

Receivers [80]
Dean [88]
direct-current [84]
early [80]
Kellogg [83]
modern [81]
Monarch [86]
operator's [90]
single-pole [81]
symbols [91]
Western Electric [82]
Reluctance [147]
Repeating coil [168]
Ribbon fuses [313]
Ringer symbols [131]
Ringing and listening key [327]
Robert's latching relay [276]
Robert's self-cleansing arrester [297]
Rolled condenser [182]

Saw-tooth arrester [296]
Selective party-line systems [238]
broken-line method [261]
classification
broken-line systems [239]
harmonic systems [238]
polarity systems [238]
step-by-step systems [239]
harmonic method [248]
polarity method [239]
step-by-step method [259]
Self-induction [54]
Signal code [235]
Signaling, method of [115]
Silk and cotton insulation [155]
Single electrode [64]
Single-pole receiver [81]
Sneak-current arresters [305]
Solid-back transmitter [66]
Sound
characteristics of [19]
loudness [20]
pitch [20]
timbre [21]
Standard cell [113]
Step-by-step lock-out system [67]
Step-by-step method of selective signaling [259]
Subscribers' station protectors [312]
Switchboard cords [349]
Switchboard plugs [348]
Switchboard transmitter [79]
Symbols
battery [114]
condenser [184]
generator [127]
hook switch [141]
impedance coil [165]
induction coil [171]
receiver [91]
repeating coil [171]
ringer [131]
ringing and listening key [327]
transmitter [79]

Table
condenser data [184]
copper wire [151]
German silver wire — 18 per cent [174]
German silver wire — 30 per cent [175]
metals, behavior of, in different electrolysis [95]
signal code [235]
specific inductive capacities [181]
temperature coefficients [172]
transmission distances, limiting [57]
winding data for insulating wires [160]
Tandem differential electromagnet [152]
Telegraph sounder [30]
Telephone currents, measurements of [36]
electromagnetic method [37]
thermal method [37]
Telephone exchange, features of [317]
districts [318]
subscribers' lines [318]
switchboards [319]
toll lines [318]
trunk lines [318]
Telephone lines [47]
conductivity of conductors [49]
electrostatic capacity [50]
inductance of circuit [54]
inductance vs. capacity [56]
insulation of conductors [56]
transmission [60]
Telephone sets [207]
classification of [208]
common-battery telephone [208]
magneto telephone [208]
wall and desk telephones [208]
common-battery [217]
desk [220]
hotel [219]
wall [219]
magneto [209]
circuits of
bridging [215]
series [212]
desk [211]
wall [209]
Temperature coefficients [172]
Thermal method of measuring telephone currents [37]
Timbre [21]
Toroidal impedance coil [165]
Toroidal repeating coil [170]
Transmission, ways of improving [60]
Transmitters [63]
acousticon [77]
Automatic Electric Company [72]
carrying capacity [76]
conventional diagram [79]
electrode [75]
arrangement of [63]
multiple [65]
single [64]
granular carbon [66]
Kellogg [70]
materials [63]
Monarch [73]
packing [75]
sensitiveness [77]
switchboard [79]
symbols [79]
variable resistance [63]
Western Electric solid-back [66]

Under-tuned ringer [252]

Vacuum arrester [299]
Variable resistance [63]
Vibrating bell [40]
Visible signals [43]
electric lamp [44]
electromagnetic [43]
Volta [92]
Voltaic cell [92]
amalgamated zincs [97]
difference of potential [94]
local action [96]
polarization [96]
theory [93]

Wall telephone hooks [135]
Dean [137]
Kellogg [135]
Western Electric [136]
Western Electric
air-gap arrester [298]
desk stand hook [138]
drop and jack [343]
receiver [82]
ringer [128]
solid-back transmitter [66]
station arrester [313]
wall telephone hook [136]
White transmitter [66]
Wire gauges [154]