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