Elizabeth, Queen, 274 England: 32; petroleum discovered in, 56; gas-lighting in, 63 _et seq._; 166, 251, 274 Erbia, 85 Esquimaux: 18; use of artificial light by, 31 Ethylene, 106 Factories: 13; artificial light in, 239 _et seq._ Faraday, 113 Filaments, carbon, 129 _et seq._ Finsen: 273, 274, 275; on stimulating action of artificial light, 277; 279, 280 Fire: importance of, to man, 5 _et seq._; man's dependence upon, 15; mythical origin of, 16; making, 17 _et seq._; production of, in the stone age, 18; in early civilization, 19; ancient worship of, 29, 299 Fireflies: 24, 81, 96, 148, 149, 150 "First Men in the Moon, The," H. G. Wells, cited, 148 Fish: artificial light as bait for, 249 Flame-arcs, 120, 121, 122, 187 Flames: 86, 88, 89; open, 233, 234 _et seq._ Flint, 33 Fool's gold, 18 Fort Wagner, 185 France: lamps in, 55; early gas-light in, 72 Franchot, invention of moderator lamps by, 55 Frankland, 77 Franklin, Benjamin: 165; quoted, 210-212; 213 Fresnel, 167, 196 Friction, 16, 17 Gas: 13, 22; discovery of coal, 32, 33; early uses of, as light-source, 63 _et 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, 97 _et 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, 341 Gas-burners: 63, 64, 77; candle-power of pioneer (table), 79; improvements in, 84 Gas-mantle: 61, 81; influence of, 99; characteristics of, 100 _et seq._; 187 Gas-meter, Clegg's, 76 Gasolene: lamps, 55; 57 Gassiot, 114 Gauss, 196 Geissler, 146 General Electric Company, 132, 135, 136 Germany: development of lamps in, 56; early gas-lighting in, 72 Glass, 195, 290 _et seq._ Glowers, 139 Glow-worms, 24 Glycerides, 52 Gold, 293 Gout, 275 Gramme dynamo, 117 Grass: 18; carbon filaments, 129 Greece: 39; sacred lamps in ancient, 41; 42 Greenhouses, carbon-filament lamps in, 250 _et seq._ Hall of Fame, 134 Happiness, effect of artificial light upon, 14 Hayden and Steinmetz, 253 Health, artificial light in relation to, 269-283 Helium, 89 Hemig, 155 Hemp, 21 Henry, William, 75 Herodotus, 56 Hertz, 68 Hertzian waves, 271 Hewitt, Cooper, produces mercury-arcs, 124, 125 Home: artificial light in relation to, 6; lighting, 325 _et seq._ Hindu: light in, ceremonials, 40 Hudson-Fulton Celebration, 306 Huygens, 195 Hydrocarbons, 82 Hydrogen, 81 Illiteracy, artificial light and, 9 Invention, 7, 97 Iowa, 238