0 _et seq._;
analytical production of, 103, 104;
yield of, retort (table), 105;
analysis of, 106

Coal-mines, 234 _et seq._

Cobalt, 294

Coke, 68, 105

Cologne, 157, 158

Colomb, Philip, 197

Color: 9;
relation of artificial light to, 284 _et seq._

Colza, 31, 52, 167

Combustion, 82 _et seq._

Commerce, 8, 97

Constantine, 42

Copper, 262, 295

Cornwall, 63

Cotton: 101;
carbon filaments, 129, 130

Cromartie, 78

Crookes, 90, 146

Crosley, Samuel, improvement of gas-meter by, 76

Crusies, 32

Daguerre, 258

Dancing, 346

Davy, Sir Humphrey: 33, 68, 73;
first use by, of charcoal for sparking points, 112;
notes of, on electric arc, 113; 114

Daylight, artificial, 12: 284 _et seq._;
application of, 287

Daylighting, 12-14

Dollond, 195

Doty, 61, 167

Drake, Col. E. L., discovery of oil in Pennsylvania by, 56

Drummond, Thomas: 171, 185, 196;
quoted on signaling, 197

Dudgeon, Miss, 251, 252

Dyes, 256, 265

East Indies, 29

Eddystone Light, 166, 167

Edison: and problem of electric incandescent filament lamps, 128 _et seq._;
129;
quoted on birth of incandescent lamp, 130

Edward I, 274

Edward VI, 49

Efficiency, effect of artificial light upon, 14

Eggs: relation of artificial light to production of, 247, 248

Egypt: 31;
sacredness of light in ancient, 39; 153, 195

Electric filament: 81, 127 _et seq._:
approximate value of, lamps (table), 138

Electric pile: construction of, 111; 127

Electricity: 13, 22;
as a light-source, 57;
for home-lighting, 62, 84; 87, 89;
ignition of gas by, 102;
lighting by, 109 _et seq._

Electromagnetic waves, 68, 86, 87

Electromagnets, 114, 116

Electrodes, 113, 114, 115 _et seq._;
life of, 122

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.