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

Iridium, 129

Iron, 18, 2