Electricity and Magnetism

by Elisha Gray

Acetylene gas at Niagara, [230].
Alexandria, temple with loadstone, [20].
Amber—elektron, [6].
Ampère, theory of magnetism, [25].
unit of electrical current, [85].
galvanometer, [93].
Aluminum at Niagara, [223].
Arabians, magnetic needle, [21].
Arago, germ of electromagnet, [93].
Aristotle mentions torpedo, [6].
refers to magnet, [20].
Atmospheric electricity, Ch. [VIII], [77].
Atoms and molecules, [39].
of substances differ in weight, [42].
relations to heat, [42].
Aurora Borealis, [35].
Bain chemical telegraph register, [101].
Barlow on galvanism in telegraphy, [93].
Bell, Alexander Graham, radiophone, [171].
Bleaching-powder at Niagara, [218].
Branly invents the coherer, [179].
Cables, submarine. See Submarine Cables.

Calcium-carbide at Niagara, [228].
Capacity of a circuit, [118], [119].
Caustic soda, [221].
Chinese, magnetic needle, [21].
Chlorine and sodium, [219].
Circuit-breaker at Niagara, [199].
Closed circuit and current, [122].
Coherer (wireless telegraphy), [179].
Columbus, compass variations, [22], [34].
Condenser in resistance-coil, [118].
in Morse relays, [131].
Conductors and non-conductors of electricity, [47].
relation to electric light, [50].
different resistances, [74], [83].
Cooke, needle telegraph, [108].
Crookes, Prof., X-ray, [121].
Cuneus and the Leyden jar, [8].
Curiosities, Ch. [XX], [171].
Daniell battery, [85].
Differential magnet, [115].
Dinocares and the loadstone, [20].
Dolbear, Amos E., wireless telegraphy, [178].
Dupay discovers positive and negative electricity, [8].
Duplex telegraphy, [114].
Dynamo-electric machines, [67].
invented by Faraday, [14], [69].
usual construction, [70].
at Niagara, [192].
Double transmission, [115].
Earth electric currents, in telegraphy, [99], [116], [182].
Earth magnetism, [32].
effects of, on iron, [35].
Aurora, [35].
telegraph-lines, [36].
from sun's heat, [75].

Edison, Thomas, railway telegraphy, [131].
electromotograph, [175].
Electric currents, Ch. [VI], [49].
not currents but atomic motion, [54].
induction of, [56].
guarded against, [169].
at Niagara, [193].
Electric generators, Ch. [VII], [62].
frictional, [49].
galvanic batteries, [62].
storage-batteries, [64].
dynamos, [67], [192].
metal heating, [74].
Electricity, science of, [6].
achievements of, [16].
eras in science of, [18].
theory of, Ch. [V], [39].
not a fluid, a form of energy, [40].
static and dynamic, [46].
measurement of, Ch. [IX], [83].
Electric light, cause of, [50].
Electric machines, [49].
frictional, [51].
galvanic or chemical, [51].
mechanical, [70].
Electromagnet invented by Faraday, [14].
commercial value, [23].
theory of (soft iron), [26].
permanent (steel), [28].
condition of use, [30].
the earth a, [32].
germ of, [93].
differential, [115].
Electromotograph, [175].
Ellsworth, Miss, sends first telegraphic message, [96].
Ether, lines of force, [31].
nature of, [40].

Ether, impressed by atomic motion, [56].
inducing electric action, [56].
Farad, unit of capacity, [118].
Faraday, Michael, [14].
Farmer, Moses G., double transmission, [114].
Field, Cyrus W., lays first Atlantic cable, [156].
Field of a magnet, [31].
Fitzgerald, Niagara Falls chemist, [210].
Franklin catches the lightning, [8].
identity of lightning and electricity, [10].
kite experiment, [11].
electric firing-telegraph, [88].
Frode, history of Iceland, [21].
Gadenhalen uses magnetic needle 868 A.D., [21].
Galileo's seed-thought, [89].
Galvani, Luigi, and galvanism, [12].
Galvanic batteries, [62].
author's experience, [65].
Galvanometer, [75], [93].
Gilbert, Dr., frictional electricity, [7].
Gintl, double transmission, [114].
Gray, Elisha, constructs voltaic pile, [65].
electrically transmits music, [91].
experiments on transmission of music, articulate speech, and multiple messages, [123].
files telephone caveat, [135].
musical experiments, [136].
speech receivers, [139].
boys' telephone, [141].
first telephone specification on record, [143].
dial-telegraph, [161].
automatic-printing telegraph, [163].
telautograph, [165].
electric musical receiver, [175].
Gray, Stephen, electrician, [8].

Grier, John A., quoted, [67].
Guyot of Provence mentions mariner's compass, [21].
Halske, double transmission, [114].
Harmonic telegraphy, [120].
receivers, [125].
relay, [130].
Hawksbee, Francis, electrician, [7].
Heat, a mode of motion, [40].
related to atoms, [42].
begins and ends in matter, [44].
electrical and mechanical energy the same, [46].
Henry, Joseph, first practical telegrapher, [90].
constructs long-distance line, [94].
produces induction, [177].
Heraclea and the loadstone, [20].
Hertz experiments in ether-waves, [178].
Homer refers to loadstone, [20].
Horse-power, [214].
House, Royal E., printing telegraph, [108], [110].
Hughes, David E., printing telegraph, [108], [112].
Induction, [56].
guarded against, [169].
produced by Henry, [177].
Keeper of a magnet, [31].
Kelvin, Lord (Sir W. Thompson), cable message receiver, [158].
"Kick," in telegraphy, [115], [118].
Kleist and the Leyden jar, [8].
"Let her buzz," [3].
Leyden jar invented, [8].
Lightning, electricity; Franklin, [8].
restoration of equilibrium, [78].

Lightning-rods, [80].
dangerous conductors, [81].
Loadstone, [20], [21].
Maury, Lieut., deep-sea soundings, [155].
Magnes, Magnesia, [20].
Magnet, electro. See Electromagnet.
Magnetic earth poles, [23], [32].
Magnetic lines of force, [31], [34], [60].
Magnetic needle, [21].
variation of, [22].
dip of, [22].
action of, [33].
Magnetism, history of, [20].
and electricity mutually dependent, [24].
theories of, [24].
in iron and steel, [25].
in the earth, [32], [36].
and sun-spots, [37].
Magnetization, limit of, [31].
Marconi, wireless telegraphy, [178-180].
Measurement of electricity, [83].
ampère, unit of, [85].
method of, [86].
Mercury luminous by shaking, [7].
Micro-farad, unit of capacity, [119].
Molecules of iron and steel natural magnets, [25].
and atoms, [39].
Morse, S. F. B., devises code of telegraphic signals, [95].
induces Congress to construct line, [96].
transmits battery current through water, [177].
Motion universal, [38].
causes sound, heat, light, and electricity, [39].
Multiple transmission, Ch. [XIII], [114].
duplex, [116].
quadruplex, [118].

Multiple transmission, musical, [120].
Musical message receivers, [125], [139].
Musical tones transmitted, [91], [92], [120], [136].
Muschenbroeck, Prof., and the Leyden jar, [8].
Newton, Sir Isaac, electrician, [8].
Niagara Falls Power, Chs. [XXII] to [XXVIII], [186] to [233].
Introduction—rock, water, power, [186].
Appliances:
tunnel, power-house, [190].
shaft, dynamos, [192].
current, [193].
governor, [194].
water-head, [195].
crane, [196].
circuit-breaker, [199].
transformer, [200].
electromotive force, [204].
Electrical Products—Carborundum, [209].
materials, [210].
furnaces, [211].
electric current, [213].
horse-power, [214].
method of work, [215].
Bleaching-powder, [218].
chlorine and sodium, [219].
method of work, [220].
caustic soda, [221].
Aluminum, [223].
crucibles and methods, [224].
magnetic effects, [226].
Calcium carbide, [228].
process, [229].
acetylene gas, [230].
Other products, [232].

Oersted, galvanic current on magnetic needle, [93].
Ohm, G. S., resistance unit, [74].
Patents—Caveat and application, [135].
Planté, storage-battery plates, [64].
Pliny mentions electrical properties of amber, [67].
loadstone, [20].
Preece, double transmission, [114].
Prescott, Geo. B., quoted, [104], [106], [163], [174].
Ptolemy Philadelphus and loadstones, [20].
Pythagoras refers to natural magnets, [20].
Radiophone, [171].
Railway train telegraphy, [131].
Richman, Prof., killed, [12].
Reiss, metallic telephone transmitters, [122].
Resistance, unit of, [74].
-coil, [118].
Siemens, double transmission, [114].
Selenium in radiophone, [172].
Shephard, Charles S., induction-coil, [122].
Stager, Gen. Anson, telegrapher, [110].
Stearns, Joseph B., cures the "kick" in double transmission, [115].
Storage-battery, [24].
Strada, loadstone telegraph, [88].
Submarine cables, Ch. [XVII], [154].
first lines, [154-5].
Maury's deep-sea soundings, [155].
first Atlantic, [156].
retardations, [157].
receiver, [158].
Sun-spots and magnetic storms, [37].
Telautograph, Ch. [XIX], [165].
Telegraph:
heliostat, [68].
semaphore, [68].
loadstone, [88].
Franklin's electric firing, [88].
electrically dropped balls, [88].
electric transmission of musical tones, [91].
of signals, [94].
Morse register, [95].
first line, [97].
description, [98].
reading by various senses, [100].
Bain, chemical recorder, [101].
Cooke needle, [108].
Wheatstone needle, [108].
House printing, [108], [110].
Hughes printing, [108], [112].
automatic systems, [109], [112].
multiple transmission, [114].
musical transmission, [120].
musical receivers, [125].
Way duplex, [129].
from moving railway trains, [131].
repeater, [150].
short-line dials, [159].
printing, [163].
wireless, Ch. [XXI], [176].
Telegraphic messages, receiving, [103].
Telephone, Chs. [XV], [XVI], [134], [145].
author's first experiment, [91].
experiments, [123].
caveat, [135].
speech receivers, [139].
boys' telephone, [141].
first specification of, on record, [143].
how telephone talks, [145].
simple construction, [146].
two methods of transmission: magneto and varied resistance, [142], [149].
limit of transmission, [153].
central station, [164].
affected by heat-lightning, [183].
Telephote, [173].
Thales of Miletus first described electrical properties of amber, [6].
Theophrastus mentions amber, [6].
Thermo-electric pile, [75].
Torpedo, the, [6].
Transformers at Niagara, [200].
Transmission, multiple, Ch. [XIII], [114].
Trowbridge, Prof., telephones through the earth, [188].
Tunnel at Niagara, [190].
Tyndall, and Gray's experiments, [92].
Unrest of the universe, [38].
Volt, unit of electrical pressure, [85].
Volta, Alessandro, and the voltaic pile, [13].
Watt, James, [86].
unit of electrical power, [86].
Way duplex system, Ch. [XIV], [129].
Wheatstone transmits musical tones mechanically, [92].
needle telegraph, [108].
dial-telegraph, [159].
Wireless telegraphy, Ch. [XXI], [176].
signaling by ether-waves, [176].
Morse and Henry, [177].
Trowbridge, Dolbear, Hertz, [178].
Branly, Marconi, [179].
Marconi's system, [180].
by earth-currents, [182].
Wolimer, King of Goths, a natural battery, [7].