318 



INDEX 



Climate, types of, 51 ; factors that deter- 

 mine, 53; effect of, on life, 54 



Clothing, scientific reasons for wearing, 

 142; sources of fibers for making, 142; 

 how kept clean, 143; removal of stains 

 from, 144 



Clouds, 34, 35, 36 



Clutch, of -automobile, 297 



Coal, 122; products derived from, 123; 

 harnessing energy of, 164 



Coccus, 216 



Cockroaches, 224 



Cohesion, 277 



Cold wave, cause of, 48 



Color, cause of, 103; of the sky, 105 



Combustion, 119; and burning, 120; prod- 

 ucts of, 121 ; spontaneous, 139 



Comets, 183-184 



Communication, early history of, 264; by 

 telegraph, 266; by telephone, 272; by 

 wireless, 277 ; by radio, 282 



Commutator, 248; in the generator, 250 



Compass, 245, 246 



Compound, 21 



Compressed air, in automobile lift, 13 ; in 

 hammer, 13; in caisson, 14; in brakes, 

 14 



Compression, 16; heat from, 120 



Concave lens, 112 



Condensation, 33 



Condenser, 282 



Conduction, of electricity, 241 ; of heat, 

 129, 130, 131 



Conglomerate, 199 



Conservation of energy, 120 



Constellation, 171, 176 



Contract, 126 



Convection, 129-132 



Convection currents and winds, 39 



Convex lens, 112 



Cooking, of foods, 88 



Cooling system of automobile, 296 



Cooper, Peter, 299 



Corn borer, 226 



Cornea, 113 



Corpuscle, 92, 95 



Coste, 291 



Cotton, 142 



Cottony cushion scale, 226 



Counter clockwise, 38 



Cross breeding, 237 



Croton dam, 64 



Crystal, in wireless and radio, 280 



Crystalline, 1% 



Culex, 223 



Cultivation of soil, 210 



Cumulus clouds, 33, 36 



Current, alternating, 250; direct, 250 



Currents, electric, measurement of, 260 ; 

 water, analogy of to electric, 260 



Cyclone, 38, 40 



Dam, Ashokan, 64; Croton, 64; Bagnell, 



167 



Damped waves, 284 

 Daniell, 5 

 D'Arlandes, 309 

 Day and night, changes in length of, 187; 



causes of, 190 

 Deafness, cause of, 19 

 Death rate from typhoid, 69 

 Decay, bacteria of, 218 

 Deceleration, 147 

 De Forest, Lee, 283 

 Density, 147, 152; of the earth, 198 

 Desert climate, 54 

 Dew, cause of, 35 

 De Witt Clinton, The, 299 

 Dew point, 29, 33, 34 

 Dial telephone, 276 



Diaphragm, 11, 16; of cornea, 114 



Diesel engine, 166; in trains, 300; in ships, 

 306 



Diet, 84 



Differential, in automobile, 298 



Diffuse reflection, 105 



Digestion, of starch, 92; in the stomach, 

 92, 93 ; factors which influence, 94 



Digestive system, 93 



Dipper, Great, 173 



Direct current, 250 



Direct lighting, 110 



Dirigibles, 309, 310, 313 



Dirt, removal of from clothing, 144 



Disease, relation of bacteria to, 218; im- 

 munity to, 218; resistance to, 219; fu- 

 migation for, 219; relation of house fly 

 to, 222; relation of rats to, 224 



Disinfectant, 57, 215 



Dispersion of light, 106 



Displacement of ships, 305 



Distillation of water, 58, 60 



Distributor, 296 



Doldrums, 38 



Domesticated plants, 237 



Draco, 173 



Drafts of stove, 132 



Drainage of soil, 211 



Drainage of swamps, 224 



Driven well, 63 



Dry cell, 240, 242 



Dry earth toilet, 73 



Dry farming, 211 



Duplex telegraphy, 270 



Duraluminum, 309 



Dusting, for insect pests, 227 



Dynamo, 248, 291 



Ear, 18, 19 



Earth, inclination of on its axis, 52; as a 

 planet, 182; as a heavenly body, 187; 

 nature of surface of, 188 ; size and 

 weight of, 188; age of, 196; formation 

 of, 197; composition of, 198; weight of, 

 198 



Earthquakes, 206 



Eating, rules for healthful, 84 



Echo, 18 



Eclipse, 186, 190 



Edison effect, 283 



Edison, Thomas A., 101 



Edwards, Jonathan, 234 



Efficiency, 156; of machine, 161 



Effort, 158 



Egg, 230 



Electric bell, 273 



Electric bill, 261 



Electric bulb, 104, 110 



Electricity, from rubbing, 240, 241 ; from 

 chemical sources, 240, 242 ; what it is, 

 241 ; from magnetism, 248, 249 ; and 

 heating devices, 252, 255 ; and light, 

 256; and motors, 252; measurement of, 

 259; water analogy of, 260; calculating 

 cost of, 261; in wireless, 280; in mod- 

 ern transportation, 301 



Electric light, 99, 101, 102; illuminating 

 power of, 109 



Electric locomotive, 301 



Electric meter, 259 



Electric refrigerator, 31 



Electrolysis of water, 58 



Electromagnet, 245, 246; in telephone re- 

 ceiver, 274 



Electrons, 240; in the atom, 241; and the 

 electric current, 241 ; pathway of 

 through telephone transmitter, 274 ; in 

 wireless, 280 



Elements, 21, 80; in human body, 81; 

 needed for soil fertility, 211 



Embryo, 231 



Energy, kinds of, 120; transformation of, 

 120; law of conservation of, 120; 

 sources of in the United States, 121 ; 

 potential, 162; kinetic, 162; of gas, 163; 

 of oil, 163; of coal, 164; of falling 

 water, 166; solar, 168; electrical from 

 chemical, 242 ; electric, generation and 

 distribution of, 251 ; heat from elec- 

 trical, 254; mechanical from electrical, 

 257; defined, 12, 156; in evaporation, 

 30 ; and foods, 77 ; release of from 

 human body, 96 



Engine, steam, 163, 164; gasoline, 295 



Environment, 215; a cause of variation, 

 233 ; relation of to heredity and train- 

 ing, 234 



Equator, 52 



Equinox, 186; vernal, 191; autumnal, 191 



Erosion, agents of, 203 ; danger of too 

 much, 204 



Ether, theory of, 104; wave lengths of 

 visible spectrum, 106 ; waves in, 106, 

 278; infra-red waves, 107; radio waves, 

 107; wireless waves, 107; defined, 277 



Eugenics, 235 



Euglena, 229 



Evaporation, 29 ; factors that affect, 29, 30 ; 

 cooling effect of, 32 



Exhale, 21 



Expansion of air, 38 



Explosion, 24 



Extinguisher, fire, 140 



Eye, parts of, 112, 113; working of, 113; 

 defects of, 113; care of, 113; adjust- 

 ment of focus of, 113 



Fabrics, removal of stains from, 144 



Fahrenheit, 43 



Faraday, Michael, 247, 249 



Farsightedness, 113 



Fats, test for, 80; nature of, 81 



Faucets, types of, 72 ; repair of, 72 



Federal Radio Commission, 286 



Fermentation, 87 



Fertilization, in flowers, 231 ; in frogs, 231 



Fertilizers, and soil fertility, 212; types of 

 213 



Fibers, sources of, 142 



Field coils, 248 



Filament, 282; in vacuum tube, 285; in 

 ^ electric bulb, 104; of pistil, 231 



Film, camera, 115; motion picture, 116 



Filter, home, 63 



Filtration of water, 58, 60 



Fire, kindling of, 138 ; control of, 138 : 

 hazards of, 139; extinguishing of, 140 



Fire extinguisher, 137, 139, 140 



Fireplace, 132 



Fixed pulley, 159 



Fleas, 224 



Fleming valve, 283 



Floating bodies, 303, 304, 306 



Flower, parts of. 229, 231 ; function in re- 

 production, 231 ; and pollination, 231 



Focus of lens, 112 



Fog, 34, 35, 37 



Food, 77; and soil fertility, 79; tests for, 

 80; classes of, 81 ; rich in vitamins, 82; 

 selection of, 83; cooking of, 88; spoil- 

 age of, 88; preservation of, 89; adu'- 

 teration of, 90; digestion of, 93; ab- 

 sorption of, 94; circulation of, 95 



Food supply, factors that control, 79 ; and 

 bacteria, 217 



Foot candle meter, 110 



Foot pound, 156 



Force, 146, 156; centrifugal, 146; centrip- 

 etal, 147 



Force pump, 9 



