Aaron,43Accidents:8;street-lighting in relation to,225et seq.;percentage (table) of, due to improper lighting,231Acetylene:62;light-yield of,106,107,170,187,191Actinic rays: effect of, upon human organism,275Africa, public lighting in ancient,31Agni, god of fire,40Air-pump,130Air-raids,225Alaska,18,29Alchemy,20Aleutians,18Alexandria,43,163Allylene,106Aluminum,108,179,180Amiens, Treaty of,69Amylene,106Aniline dyes,106Animal: distinction between, and human being,3;15;production of light,24et seq.;sources of light,30,31;oils,51Antimony,294Antioch,153Arago,114,196Archbishop of Canterbury,49Archimedes,19Arc: lamps,69,89;electric,111et seq.;distinction between spark and,112;Davy's notes on electric,113;formation of,115,116;Staite and enclosed,117,118;principle of enclosed,118,119;types of,120;flame-,121,122;luminous,122;electric,127;luminous efficiency of electric (table),124;160et seq.;-lamp in lighthouses,168et seq.;magnetite-,187;261Ardois system of signaling,199Argand, Ami:52;inaugurates new era in artificial lighting,53,54;63,70,76,77,78,97,167,196Argon,137Aristophanes, "The Clouds,"19Art Museums,9,13,322,323Asbestos,170Asia: public lighting in ancient,31,39Automobiles,238Babylon,39Bacteria: effect of artificial light upon,272et seq.;281,282Bailey, Prof. L. H.,250Baltimore,98Bamboo: carbon filaments,169Bartholdi,302,303Beacons.SeeLighthouses.Beck,186Beecher,72Beeswax,35,51Benzene,106Bible, cited on importance of artificial light,42-44"Bluebird, The," Maeterlinck,9Blue-prints,261Bollman,98Bolton, von,132,133Bombs, illuminating,182et seq.Boston Light,164,165,166,177Bowditch, production of regenerative lamp by,78,79Boy Scouts,17Bremer,120Bristol University,252Brush,68,159Building,8Bunsen,81,85,89,148,149Bureau of Mines: cited on open flames,234;236Burning-glasses,19,20.See alsoLenses.Butylene,106Byzantium,34Cæsar,163Canada,254Candle-hour, defined,215Candles: progress and,7;25,28,29,30,33;religious uses of,34,35;as a modern light-source,36,37;ceremonial uses of,38et seq.;44,48,57,82,97,222,299,304Calcium,107,108Carbolic acid,106Carbon:53,80,81;physical characteristics of,80,81;90,104,105,128,129,144,170Carbon filament:127et seq.;preparation of,129,130,131;luminous efficiency of,131,132;lamps,161;lamps in greenhouses,250et seq.Carbons, formation of,115,116Carbureted hydrogen,75Carcel, invention of clockwork lamp by,54,55Cat-gut,130Ceria,85,101Charleston, S. C.,185Charcoal:113;uses of, for electrodes,115Chartered Gas Light and Coke Co., London,74Chemistry: artificial light and,256-268Chicago,62,304,305Chimneys,54,60,62China,19,31,32Chlorate of potash,22Christ,33,46,47Christians, "children of light,"42Christmas trees,43,304Chromium,294Church of England,49Cities: economy of artificial lighting in congested,13Civilization: effect of artificial light upon,4et seq.;fire and,15Clark, Parker and,139Clayton, Dr.: invention of portable gas-light by,64;quoted,64,65;experiments of, with coal-gas,67Claude,147Cleaves, Dr., quoted,276,277Clegg, Samuel:74;gas-lighting accomplishments of,75,76Cleveland,159"Clouds, The," Aristophanes,19Coal:32;as a light-source,55;supply,223;228Coal-gas:63et seq.;public lighting by, developed,70et seq.;analytical production of,103,104;yield of, retort (table),105;analysis of,106Coal-mines,234et seq.Cobalt,294Coke,68,105Cologne,157,158Colomb, Philip,197Color:9;relation of artificial light to,284et seq.Colza,31,52,167Combustion,82et seq.Commerce,8,97Constantine,42Copper,262,295Cornwall,63Cotton:101;carbon filaments,129,130Cromartie,78Crookes,90,146Crosley, Samuel, improvement of gas-meter by,76Crusies,32Daguerre,258Dancing,346Davy, Sir Humphrey:33,68,73;first use by, of charcoal for sparking points,112;notes of, on electric arc,113;114Daylight, artificial,12:284et seq.;application of,287Daylighting,12-14Dollond,195Doty,61,167Drake, Col. E. L., discovery of oil in Pennsylvania by,56Drummond, Thomas:171,185,196;quoted on signaling,197Dudgeon, Miss,251,252Dyes,256,265East Indies,29Eddystone Light,166,167Edison: and problem of electric incandescent filament lamps,128et seq.;129;quoted on birth of incandescent lamp,130Edward I,274Edward VI,49Efficiency, effect of artificial light upon,14Eggs: relation of artificial light to production of,247,248Egypt:31;sacredness of light in ancient,39;153,195Electric filament:81,127et seq.:approximate value of, lamps (table),138Electric pile: construction of,111;127Electricity:13,22;as a light-source,57;for home-lighting,62,84;87,89;ignition of gas by,102;lighting by,109et seq.Electromagnetic waves,68,86,87Electromagnets,114,116Electrodes,113,114,115et seq.;life of,122Elizabeth, Queen,274England:32;petroleum discovered in,56;gas-lighting in,63et seq.;166,251,274Erbia,85Esquimaux:18;use of artificial light by,31Ethylene,106Factories:13;artificial light in,239et seq.Faraday,113Filaments, carbon,129et seq.Finsen:273,274,275;on stimulating action of artificial light,277;279,280Fire: importance of, to man,5et seq.;man's dependence upon,15;mythical origin of,16;making,17et seq.;production of, in the stone age,18;in early civilization,19;ancient worship of,29,299Fireflies:24,81,96,148,149,150"First Men in the Moon, The," H. G. Wells, cited,148Fish: artificial light as bait for,249Flame-arcs,120,121,122,187Flames:86,88,89;open,233,234et seq.Flint,33Fool's gold,18Fort Wagner,185France: lamps in,55;early gas-light in,72Franchot, invention of moderator lamps by,55Frankland,77Franklin, Benjamin:165;quoted,210-212;213Fresnel,167,196Friction,16,17Gas:13,22;discovery of coal,32,33;early uses of, as light-source,63et seq.;installment of, pipes in England,63,64;Shirley's report on Natural,66,67;first public display of, lighting,69;cost of, lighting,71;first attempt at industrial, lighting,72;first English, company,74;first, explosion,75;house, lighting,76,77;80,82;spectrum of,90;modern, lighting industry,97et seq.;origin of lighting by,98;first, works in America,98;growth of, consumption in United States,99;electrical ignition applied to, lighting,102;pressure,102,103;water,105;carbons in,106;production of Pintsch,109,110;salts applied to, flames,120;157;Census Bureau figures on cost of, plants,221,222;224,341Gas-burners:63,64,77;candle-power of pioneer (table),79;improvements in,84Gas-mantle:61,81;influence of,99;characteristics of,100et seq.;187Gas-meter, Clegg's,76Gasolene: lamps,55;57Gassiot,114Gauss,196Geissler,146General Electric Company,132,135,136Germany: development of lamps in,56;early gas-lighting in,72Glass,195,290et seq.Glowers,139Glow-worms,24Glycerides,52Gold,293Gout,275Gramme dynamo,117Grass:18;carbon filaments,129Greece:39;sacred lamps in ancient,41;42Greenhouses, carbon-filament lamps in,250et seq.Hall of Fame,134Happiness, effect of artificial light upon,14Hayden and Steinmetz,253Health, artificial light in relation to,269-283Helium,89Hemig,155Hemp,21Henry, William,75Herodotus,56Hertz,68Hertzian waves,271Hewitt, Cooper, produces mercury-arcs,124,125Home: artificial light in relation to,6;lighting,325et seq.Hindu: light in, ceremonials,40Hudson-Fulton Celebration,306Huygens,195Hydrocarbons,82Hydrogen,81Illiteracy, artificial light and,9Invention,7,97Iowa,238Iridium,129Iron,18,262,294Iron pyrites,18Italy,249Jablochkov: electric candle of,117Jamaica,19Jandus,118,122Japan:19;use of oil in,30;281Jerusalem,43Jews: artificial light among,40Journal, Paris, quoted,210-212Kerosene:57;weight of, lumens,60;62,187,233Kitson, platinum-gauze mantle applied by,61Laboratories: achievements of,137Lamps:16,25;Roman,30;31;invention of safety,33;ancient funereal,39;sacred, of antiquity,41;ceremonial,44;scientific development of oil,51et seq.;Holliday,55;Carcel,54,55;Franchot's moderator,55;gasolene,55;development of, in Germany,56;air pressure,61;supremacy of oil, ends,62;Bowditch's,77,78;80,97;mercury-arc,126;electric incandescent filament,127et seq.;gem,132;tungsten,133et seq.;luminous efficiency (table) of incandescent filament,141;299;in home,328-333Lange,167Lard-oil,51Lavoisier,195Lead,262,294Le Bon,72"Legend of Montrose, The," Scott, cited on primitive lighting,27Leigh, Edmund, quoted,226Lenses,20,171et seq.Libanius, quoted,153,154Liberty, Statue of,301,302,303Libraries,9Light: relation of artificial, to progress,3et seq.;as a civilizing agency,3-14;primitive man and artificial,4;Milton, quoted on importance of,5;artificial, and science,7;artificial, and industrial development,8;Maeterlinck's tribute to,9;Lincoln's debt to artificial,9;symbolism of,9,10;therapy,10;in war,11;adaptations of,12;13;mythical origin of artificial,16;earliest source of,16;production of, in stone age,18;matches as source of,21;animals as, sources,24,25;primitive sources of,24-37;evolution of artificial, sources,24-37;development,28et seq.;early outdoor use of artificial,28;Roman uses of artificial,30;beginning of scientific,33,34;candles as modern, source,36,37;symbolism and religious uses of,38et seq.;Bible cited on artificial,42-44;in relation to worship,43,45,46;Argand's contribution to,53,54;coal as, source,55;early uses of gas as, source,63et seq.;as a public utility,70;first installation of industrial gas,72;science of, production,80et seq.;causes of, radiation,80,81;83;lime,84; electric,89et seq.;principle of, production,90,91;sources,93;various gas-burners', supply,95;relative efficiency of, sources,95,96;in the home,97;influence of, upon science, invention, and commerce,97et seq.;yield of acetylene,106,107;electric,109;influence of gas upon development of artificial,110;development of artificial,111et seq.;efforts to improve color of mercury-arc,125;electric-incandescent-filament,127et seq.;effect of tungsten, upon,133et seq.;of the future,143-152;in warfare,178-193;signaling,194-207;cost of,208-224;and safety,225et seq.;improper use of,229,230;comparison of daylight and artificial,240;reducing action of,258;bactericidal action of,272et seq.;modifying,284et seq.;spectacular uses of,298-309;expressiveness of,310-324;utility of modern,325-340;evolution of the art of applying,341-356;mobile,347,348,349,350;psychological effect of,351et seq.;as an accompaniment to music,352-354Light-buoys,10,169Lighthouses:10,163-177;optical apparatus of,172et seq.Light-ships,10,169Lighting-systems: comparison of,12-14Lime,84,107,108,294Lincoln, Abraham,9Linen,18Link-buoys,28Lithopone,265,266Liverpool,167Living: comparison of, standards,238et seq.London,152,154,155,156,157,202London Gas Light and Coke Company,74Lucigen,61Lumen-hour: defined,215Lumens:60,94,215Lutheran Church,49Lyceum Theatre, London,73Maeterlinck, Maurice,9Magazines,8Magdsick, H. H.,303Magnesia:84;Nernst's application of,138Magnesium,179,180Magnetite arc,187Man: distinction between, and animal,3;artificial light and early,4;light-sources of primitive,25Manganese,262,268,294Mangin,188Mann,129Mantles,95Manufacturing,8Marconi,68Marks,118Matches: as light-sources,21;22,82Maxwell,68Mazda lamps,289,339Mecca,40Mediterranean Sea,163Mercury-arc: Way's,124;125,126;quartz,125,126;attempts to improve color of, light,125Middle Ages,46,47,274Milton, quoted,5Mirror,19Mohammedans,40Moore, Dr. McFarlan,146,147Morality, effect of light upon,9Morse code: application of, to light-signaling,198,199Moses,195Moving-pictures,9,260,261Munich,72Murdock, William: installment of gas-pipes by,63;68,69,70;quoted on industrial use of artificial,71;72,73,74,76,78,217,309Museums:13;utilization of artificial light by,322,323Music: light as an accompaniment to,352-354Mythology,16Nantes,85Napoleon,111Napthalene,106National Heat and Light Co.,72,74Natural gas,99Navesink Light,206Nernst,138,139Newspapers,8Newton, Sir Isaac:7;quoted on discovery of visible spectrum,87;88New York,98,165,166,206,302,304Niagara Falls,108,306Nickel,262Nielson,77Niepce,258Niter,21Nitrogen,137Norfolk,169Obesity,275Offices,13Oil: as a light-source,29et seq.;development of, lamps,51et seq.;155;in lighthouse,165et seq.;222,224,299O'Leary, Mrs., and her lamp,62Olive-oil,51,52,167Orkney Islands,29,177Osmium,133Oxygen: relative consumption of, by oil-lamps,58,59;262Ozone,262Painting,342,343,347,348,349Pall Mall,74Panama-Pacific Exposition:304;artificial lighting of,306,307,308,309Paper:18;carbon filaments,129,130Paraffin,35,57Parker and Clark,139Paris: experimental gas-lighting in,83,84;Volta in,111;154,185,210,212,213Peckham, John,195Pennsylvania: discovery of oil in,56Periodic Law,145Petroleum:35,51,55;discovery of,56;constitution of crude,57;58,214Pharos,163Philadelphia,98,99,157Phillips and Lee,70,72"Philosophical Transactions of the Royal Society of London,"33;quoted on industrial lighting,63;Shirley's report on natural gas in,66,67;quoted,87Phœnicians,34,39Phosphorus,21Photo-micrography,12Photography:126;early experiments in,258;development of,259;291,292Picric acid,106Pigments,265Pintsch: production of, gas,109,110,170Pitch,106Plant-growth: artificial light and,11,249et seq.Platinum,85,128,129,262Plumbago,113,130Plymouth,166Poetry,346Police,162Potash, chlorate of,22Priestley, Professor, quoted,252Printing,8Progress: influence of fire upon,15et seq.Prometheus,16,41Propylene,106Ptolemy II,163Quartz:18,19;mercury-arcs,125;uses of,126;in skin diseases,278,279Radiators, energy,88et seq.Radium,150Railway Signal Association,205Railways: light-signaling applied to,205Ramie fiber,101Rane,250,251Rare-earth oxides:85;properties of,88,99Recreation,9Redruth,63Reformation: ceremonial uses of light during the,48,49Rheumatism,275Robins, Benjamin,201Rome,30,32,34,39,41,42,44Röntgen,270,280.See alsoX-ray.Royal Society of London:33,63,66,67,70,73;and first gas explosion,75,111,112Rumford,167Rushlights,28,33Russia,281Ryan, W. D'A.,306Safety: artificial light in relation to,14,225et seq.Salts: chemical,88,89;metallic,120;silver,257,258Sandy Hook Light,165,166San Francisco,304,306-309Savages,3,15,17Sawyer,129Scheele, K. W.,133;quoted,257,258Schools,9Science: light and,6,7;97;systematized,268Scotland:26,31,32,48;oil industry in,56Scott, Sir Walter, cited,27,98Sculpture: artificial light in relation to,184Search-lights,11,169Section of Plant Protection,225,226Selenium,267,293Semaphore,199Shells: illuminating,179et seq.Shirley, Thomas: quoted on natural gas,66,67Siemens,78Signaling,194-207Silicon: filament,140Silk: artificial,101;carbon-filaments,129Simpson, R. E.,227,231Silver,258,293Skin diseases: treatment of,278,279,280Skylights,13Sleep,8Smallpox,274,275Smeaton,166Soho,69,72South Africa,129Sparks:33,125Spectrum: visible,86;Newton quoted on,87;of elements,89;of gases,90;120,121;mercury,124-126Sperm,31,51,52,167Spermaceti,35,51Splinter-holders,27,28Stage: and artificial light,319et seq.;343Staite,117,118Stearine,35,52Stearn,129Steel,18,33Steinmetz, Hayden and,253Sterilization: quartz-mercury-arc and,280,281,282Stevenson, Robert Louis, quoted,177Stores,13St. Paul,43St. Paul's Cathedral,300Street-lighting: development of,152-162Sugar,22Sulphide of iron,18Sulphur,18,21,179,180,294Sulphuric acid,21,22Sun,8,16,19,20Swan,129Syracuse,19Syria,153Tallow,34,35,51,52Tantalum:132;filament lamps,133Tar,68,106Telegraphy,195Telephony,194Textiles,256Thames,169Theaters,9,319et seq.Thoria,85Tin,262Tinder-boxes,18,19,22Travelers Insurance Company,227Trees,26Troy,42Tuberculosis,273Tungsten lamp,161et seq.,187,261,290,303Typhus,273Ultra-violet rays:126,150;in photographic electricity,267,268;270,272,294United States: petroleum in,57;gas-consumption in,99;164,165,166United States Geological Survey, cited on sale of gas,222United States Military Intelligence,225,226Vacuum tubes,81,286Venetians,195Ventilation,13Verne, Jules,143Vestal Virgins,42Volcanoes,166Volta,111,112,127Voltaic pile: construction of,111,127Von Bolton.SeeBolton.War: and artificial light,11,178-193Washington,305Water: sterilization of, by artificial light,280et seq.Watson, Dr. Richard,67,68Watt,94Waves: electro-magnetic,68,86,125et seq.Wax,34,46,51Way: mercury-arc produced by,124Wells,61Wells, H. G., cited,148Welsbach, Auer von:61;invention of mantle by,99,100,133Wenham,78West Indies,25Whale-oil,31Wicks,35,36,53,54,58,59Winsor,72,73.See alsoWinzler.Winzler.SeeWinsor.Wolfram.SeeTungsten.Wood,26,27,28Woolworth Building,302,303Wounds: treatment of, by artificial light,10X-ray: production of, tubes during War,131;137,150,270,280Young, James: discovers petroleum,56Yttria,85Zeitung, Cologne:157;extract from, on street-lighting,158Zinc,125,130,267Zirconia,84,85