Cellulose, 12, 44 Centrifugal tendency, 115 "Character" of a lighthouse, 86 Charge and current, 32 Cheddite, 13 Chemicals in waterworks, 232 Chemistry, organic and inorganic, 42 Chlorate of potash, 12 Chloride of soda, 58 Chronograph, the, 141 Clark's Cell, 23 Coal and oil, 47 Coal, burnt, 10 Coal-dust an explosive, 10 Coal-dust, explosions from, 139 Coal-pitch, 48 Coal-tar, 48 "Coasting" lights, 80 Coherer, the, 103, 162, 167 Coke in smelting, 125 Colliery explosions, 137 Colliery explosions, rescue apparatus, 226 Colours of the spectrum, 213 Colours of flowers, 213 Compass, a ship's, 91 Compressed air in torpedoes, 100 "Concentrates," 115 Condensers in wireless, 163 Conservation of energy, 132 Contact makers, 145 Coronium, the gas, 74 Corundum, 134 Coulombs, 23 Courrières colliery disaster, 221 Creosote, 48 Creosote oil, 48 Crooks, Sir W., 33 Crushing mills, 115 Crystal detectors, 171 Curie, M. and Mme., 33 Curtis and Harvey, 9 Cyanide process, the, 118 Cyanogen, 118 Cymogene, 45 D Detectors, 167 Detonator, the, 14 Dextro-glucose, 51 Diamonds, 135 Diesel engines, 46 Direct-current electric motor, 191 "Dirt-auger," the, 15 Ditches, blasting, 18 Drainage, 233 Du Pont Powder Company, 9 Duddell, W. H., 37 Dufay dioptichrome process, 219 Dynamite, what it is, 9, 12; in agriculture, 13; firing a charge, 16; fruit trees, 16; marshy ponds, 17; ditches, 18; tree stumps, 19; boulders, 19; wells, 20 Dynamo, the, 65 E Eddystone Lighthouse, 80 Edison's accumulator, 66 Einthoven, Prof., 30 Electric arc, the, 123 Electric furnace, 125 Electric fuse, the, 16 "Electrical Inertia," 153 Electrical battery, 23; pressure, 23; cells, 23; measure, 24; magnetism, 25 Electricity, 22; the current, 56; electro-plating, 58; purification of metals, 61; secondary batteries, 62 Electrode, 55 Electrolysis, 55, 170; in drainage, 234 Electrolyte, 55 Electrometer, the, 32, 34 Electro-plating, 58 Electros, 60 Electroscope, the, 34 Endosperm, the, 50 Engines driven by oil fuel, 46 Enzymes, 50 Ether, 45, 149 Ethyl alcohol, 49 Explosions, 9; in mines, 137 Explosive link, the, 104 Explosives for guns, 237 F "Falls" in a coal mine, 223 Fermentation, 50 Fessenden, R. A., 169 Field guns, 241 Filters in waterworks, 232 Fire-damp, 137 Firing-pin of torpedo, 102 Flashing lights, 81 Fog, effects of, 82 Fog signals, 88 "Fractional distillation," 76 "Frequency," 36 Frequency meter, 193 Friction clutch, 195 "Frue" vanner, the, 116 Fruit trees and dynamite, 16 Fuses, firing, 20 G Galvanometer, the, 27, 170 "Gangue," the, 112 Gauges, 208 Gelignite, 12 Glycerine in explosives, 11 Gold, 110