Staite, 117, 118

Stearine, 35, 52

Stearn, 129

Steel, 18, 33

Steinmetz, Hayden and, 253

Sterilization:  quartz-mercury-arc and, 280, 281, 282

Stevenson, Robert Louis, quoted, 177

Stores, 13

St. Paul, 43

St. Paul’s Cathedral, 300

Street-lighting:  development of, 152-162

Sugar, 22

Sulphide of iron, 18

Sulphur, 18, 21, 179, 180, 294

Sulphuric acid, 21, 22

Sun, 8, 16, 19, 20

Swan, 129

Syracuse, 19

Syria, 153

Tallow, 34, 35, 51, 52

Tantalum:  132;
  filament lamps, 133

Tar, 68, 106

Telegraphy, 195

Telephony, 194

Textiles, 256

Thames, 169

Theaters, 9, 319 et seq.

Thoria, 85

Tin, 262

Tinder-boxes, 18, 19, 22

Travelers Insurance Company, 227

Trees, 26

Troy, 42

Tuberculosis, 273

Tungsten lamp, 161 et seq., 187, 261, 290, 303

Typhus, 273

Ultra-violet rays:  126, 150; in photographic electricity, 267, 268; 270, 272, 294

United States:  petroleum in, 57;
  gas-consumption in, 99; 164, 165, 166

United States Geological Survey, cited on sale of gas, 222

United States Military Intelligence, 225, 226

Vacuum tubes, 81, 286

Venetians, 195

Ventilation, 13

Verne, Jules, 143

Vestal Virgins, 42

Volcanoes, 166

Volta, 111, 112, 127

Voltaic pile:  construction of, 111, 127

Von Bolton. See Bolton.

War:  and artificial light, 11, 178-193

Washington, 305

Water:  sterilization of, by artificial light, 280 et seq.

Watson, Dr. Richard, 67, 68

Watt, 94

Waves:  electro-magnetic, 68, 86, 125 et seq.

Wax, 34, 46, 51

Way:  mercury-arc produced by, 124

Wells, 61

Wells, H. G., cited, 148

Welsbach, Auer von:  61;
  invention of mantle by, 99, 100, 133

Wenham, 78

West Indies, 25

Whale-oil, 31

Wicks, 35, 36, 53, 54, 58, 59

Winsor, 72, 73.
  See also Winzler.

Winzler. See Winsor.

Wolfram. See Tungsten.

Wood, 26, 27, 28

Woolworth Building, 302, 303

Wounds:  treatment of, by artificial light, 10

X-ray:  production of, tubes during War, 131; 137, 150, 270, 280