INDEX 



305 



Energy, potential, 181 



Energy, source of, for plants, 75, 76 



Energy, transformations of, 181-189 



Energy and life, 188, 189 



Energy from sun, 187, 188 



Environment, changes in, 295, 296 



Environment, human, 302 



Enzymes, 249, 256 



Epidermis, 71, 73* 



Equator, heat, 45 



Erie canal, 150, 151 



Erosion, 197, 198*, *215-223 



Erosion and deposit, 220 



Erosion and vegetation, 218*, 219* 



Erosion by plants and animals, 197, 



198* 



Erosion by wind, 221* 

 Ether and evaporation, 111 

 Evaporation, 21, 109 

 Evaporation, rate of, 114* 

 Evaporation from plants, 115*, 116 



Factory, plant compared to, 78 



Fahrenheit thermometer, 11, 12* 



Farm wells, 163* 



Fermentation, 81, 82 



Filtering plants, 160 



Fire engine, 126 



Fire extinguishers, 65 



Flame, products of, *56-58, 62-65 



Flame, structure of, *55~57 



Flea, and bubonic plague, 101 



Floating objects, 133* 



Flower, *276-278 



Fluid pressure, 130 



Fluorine, 61 



Food, purpose of, 262, 263 



Food, transportation of, 247-249, 259 



Food, variety of, 264, 265 



Food in plants, 246-252 



Food manufacture, *67-78 



Food manufacture, relation of air 



to, 67-69 



Food storage, 249, 250*, 251 

 Food supply, 241-245 

 Football, 1, 6 

 Foot-pound, 177 

 Forecasting, weather, 46, 48 

 Formaldehyde, 86 

 Fort Dearborn, location of, 150 

 Forests and drainage, *216-220 

 Forests and erosion, *216-220 

 Fox, overproduction of, 288 

 Freezing, 103, 104, 108, 116, 117 

 Freezing mixtures, 116, 117 



Freezing temperature, 12, 103, 104, 



108 



Freezing water, work by, 193* 

 Friction, 173, 174, 176 

 Frog, reproduction of, 273, 274*, 275 

 Frost, action of, 193 

 Frost warnings, 48 

 Fruits and climate, 146 

 Furnaces, heating, 14 



Galveston, hurricane in, 40*, 41 



Gas, in candle flame, 56, 57*, 62-64 



Gas pressure, 53 



Gases, expansion of, 50, 52 



Gelatin, 81, 82 



Generator for carbon dioxide, 64* 



Germ diseases, 92-101 



Glaciers, *195-197 



Glass, 135 



Gold, 61, 135 



Grasslands, *229-232 



Gravel, 201, 202 



Grazing, 231, 232* 



Great Lakes, *136-139, *143-153 



Great Lakes, commercial relations 



of, 147, 148, 149*-153 

 Greenhouse, 20 

 Guard cells, 72, 73* 



Harbor, relation to railroads, 151 



Harbors, 151, 152 



Havana, Cuba, healthfulness of, 96 



Heat and molecular movement, 53 



Heat as energy, *181-189 



Heating of land and water, *140-142 



Heredity, 300-302 



Hereford, 292*, 294* 



High-pressure centers, *30-39 



Hot waves, 37, 38, *137-139 



House fly, 88, *93-96 



House fly, carrying of bacteria by, 



94*, 95* 



House fly, disposal of, 95, 96 

 House fly, life history of, *93-94 

 Humidity, *21-27 

 Humidity, absolute, *22-27 

 Humidity, relative, *22-27 

 Humidity in cyclones, 36 

 Humidity in houses, 27 

 Humidity in United States, 26*, 27 

 Humus, 203 

 Hurricanes, 40*, 41 

 Hybrids, 292-294* 

 Hydraulic press, 126, 127*, 128 

 Hydrochloric acid, 64 



