Part 37

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