INDEX 



319 



Forecasting weather, 45 



Forests and erosion, 205 



Fossils, 196, 200 



Franklin, Benjamin, 267 



Franklin stove, 132 



Free wheeling, in automobiles, 297 



Freezing and thawing in rock formation, 



202 



Frequency, 277, 282 

 Friction, heat from, 121 ; advantages and 



disadvantages of, 148; causes of, 149; 



reduction of, 149; types of, 149 

 Friction matches, 138 

 Frigid zones, 52 

 Frog, 231 

 Frost, 36 

 Frying, 88 

 Fuels, 119; types of, 121, 122; heat value, 



128 



Fuel system of automobile, 295 

 Fulcrum, 156; in lever, 158 

 Fulton, Robert, 306 

 Fumigation, 219 

 Fungi, 87, 89 

 Furnaces, 133 

 Fuse, 253, 254, 255 



Galaxy, 171, 176 



Galileo, 5, 154 



Galvani, Luigi, 242 



Galvanometer, 248, 249 



Gas, natural, 101, 123; water, 101; com- 

 position of, 101 ; from coal, 123 



Gas burner, types of, 101 ; on furnace, 136 



Gas lighting, 101 



Gas mantle. 101 



Gasoline, as fuel, 166 



Gasoline engine, cross section of cylinder 

 of, 166; experiment, 292; strokes of, 

 295 



Gasoline lamp, 100 



Gastric juice, 93 



Gauge, 12 



Gear, 156; of automobile, 297 



Germ, 221 



Giffard, Henri, 309 



Gilbert, Sir William, 239 



Glacial map, 204 



Glaciers, and erosion, 204 



Gland, 92 



Gneiss, 199 



Graf Zeppelin, 309 



Gram, 151 



Granite. 199 



Gravel, 209 



Gravitation, 150 



Gravity, and weight, 150; effect of on 

 earth's surface. 203; denned, 302 



Grease, removal of from clothing, 144 



Great Western, 304 



Greeks, early methods of communication 

 , of, 265 _ 



Grid, 282 ; in a vacuum tube, 283 



Ground water, and erosion, 203 



Gulf stream, 54 



Gullet, 93 



Gusher, oil, 124 



Gutenberg, 265 



Gypsy moth, 226 



Gyro compass, 306 



Gyroscope, experiment on, 303 ; in stabiliz- 

 ing ships, 306 



Haemoglobin, 21, 92 

 Hail, 36 



Halley's Comet, 184 

 Hard water, 61 

 Harvey, William, 95 



Health, and fresh air, 24-25 ; and food, 84; 

 and humidity, 31; and light, 113; and 

 water supply, 69 



Hearing, 19 



Ilrart, as a pump, 93 



Heat, from friction, 120, 121 ; from chem- 

 ical energy, 120; sources of, 120; a 

 form of energy, 126; measurement of, 

 128; absorption of by various sub- 

 stances, 128; transfer of, 131; from 

 electricity, 254-255 ' 



Heating systems, 130 



Heat wave, cause of, 48 



Heavy water, 59 



Hedley, William, 298 



Heiron. King, 304 



Helicopter, 308 



Helium, in the air, 23 : in balloons, 308 



Henry, Joseph. 246, 268 



Herculaneum, 205 



Hercules star cluster, 176 



Heredity, 233-234 



Hero's ball of the winds, 164 



Herschel, William, 183 



Hertz, Heinrich, 279 



Heyl, Paul R., 188 



Hieroglyphics, 265 



High, 38, 40; usual pathway across coun- 

 try, 44 



Highways, history and improvement of, 

 293 



Hindenburg, 309. 310 



Holland, John P., 306 



Hooke, Robert, 267 



Horsepower, determination of, 164 



Hot-air heating system, 132-134 



Hot-water heating system, 130, 132-134 



House fly, 222, 223, 246 



Human body, analysis of, 81 ; digestive 

 system of, 93; circulatory system of, 

 95 ; temperature regulation of, 141 



Humid, 29 



Humidifiers, home, 31 



Humidity, relative, 31 



Humus, 207; in soils, 208 



Hurricane,48 



Hydroelectric power, 166 



Hydrogen, 59 



Hydroplane. 308 



Hygrodeik, 31 



Hygrometer, 31 



Ice, artificial, 32 



Igneous rock, 198 



Illumination, 108 



Images formed by lenses, 111 



Immunity to disease, 218 



Inca methods of communication, 265 



Incandescent lamp, types of, 102 



Incident ray, 105 



Inclined plane, experiment on, 157; types 



of, 160; principles of, 161 

 Indirect lighting, 110 

 Induced current, 248 

 Induction coil in wireless, 279 

 Inertia, 146; experiment, 147; in daily life, 



151, 152 



Infantile paralysis, 224 

 Influenza. 218 

 Infra red waves, 107 

 Inherited characteristics, 236 

 Ink, removal of stains of, 144 

 Inner ear, 19 



Inoculation against disease, 218 

 Inorganic, 77 



Insects. 221-224; control of, 226 

 Insolubility, 57 

 Instruments, musical, 19 

 Insulator, 119. 240, 253 

 Intensity of light, 108 



Intestine, functions of, 95 

 Iris, 112 

 Irrigation, 211 

 Isobar, 43 

 Isotherm, 43 



Jackson and O'Brien, 312 



Japan current, 54 



Japanese beetle, 226 



Javelle water, 141 



Jenner, Edward, 218 



Juices, digestive, 93 



Jukes, Max, 234 



Jupiter, as a planet, 182; moons of, 182 



Kelvin, Lord, 239 

 Kerosene, composition of, 101 

 Kerosene lamp, light from, 98, 100 

 Key, telegraph, 268 

 Kilocycle, 282 



Kilogram, 126; standard, 151 

 Kilowatt, 258 

 Kilowatt hour, 258 



Kindling temperature, 21, 119, 138; experi- 

 ment, 137 



Kinetic energy, 162 

 Kingsford-Smith, 312 

 Kite, principle of, 311 

 Kitty Hawk, 311 

 Koch, Robert, 220 

 Kodak, first folding, 114 

 Krypton, 23 



Labrador current, 54 



Ladybird beetle, 226 



Lamp, electric, 101. 254; arc. 82, 102, 256; 

 kerosene, 99, 100; gasoline, 100 



Land breezes, cause of, 41 



Langley, S. P., 310 



Laplace, 197 



Larva, of house fly, 222; of Japanese 

 beetle, 226 ; of mosquito, 223 



Larynx, 19 



Latitude, defined, 51 ; parallels of, 192 



Laundering fabrics, 144 



Lava, 205 



Lavoisier, 1 



Lead peroxide, 240 



Leaf, in starch making, 78 



Leeuwenhoek, Antony van, 219 



Legumes, 207; and soil fertility, 212 



Lenses, image formed by convex, 111; 

 classes of, 112; effect of on light rays, 

 112 



Leonids, 184 



Lever, experiment. 156; types of, 158; 

 principle of, 158 



Leverrier, 183 



Lice, 224 



Lichens and soil formation, 209 



Life, in early geological periods, 199 ; 

 comes from life, 230 



Lift pump, 8, 9 



Light, from kerosene lamp, 99, 100; from 

 gas flame, 99, 100; history of, 99; from 

 candle. 100; from electric lamp, 101. 

 256; direction of, 103, 104; bending of, 

 103; as cause of color, 103; comi>M- 

 tion of, 104; speed of, 104; as a wave 

 motion in ether, 104; law of reflection 

 of, 105; breaking up of by prism. 106; 

 as cause of rainbow, 106 ; and illumi- 

 nation, 108; effect of walls and ceiling 

 on, 108; devices which use, 112; a"-l 

 the human eye, 113; and bacteria, 217 



Lighting, methods of, 109, 110 



