- Absorption, of heat by lampblack, 143-144.
- of gases by charcoal, 57.
- of light waves, 135-138.
- Accommodation of the eye, 123.
- Acetanilid, 259.
- Acetylene, as illuminant, 152-153.
- Acid, boric, 253.
- carbolic, 152, 251, 252.
- hydrochloric, 55, 80, 227, 238, 241.
- lactic, 230.
- oxalic, 247, 248.
- salicylic, 253.
- sulphuric, 55, 80, 240, 241, 307.
- sulphurous, 242.
- Acids, action on litmus, 220.
- Adenoids, 51.
- Adulterants, detection of, 16.
- Air, characteristics of, 81-83, 86, 189.
- Alcohol, 234.
- in patent medicines, 260.
- Alizarin, 248.
- Alkali, 222.
- Alternating current, 351.
- Alum, 247.
- Ammeter, 341, 343.
- Ammonia, 152.
- a base, 221-222.
- in bath, 226.
- in manufacture of ice, 98.
- neutralizing chlorine, 240.
- Ampere, 342.
- Anemia, 259.
- Angle, of incidence, 110.
- of reflection, 110.
- of refraction, 114.
- Aniline, 152, 245.
- Animal charcoal, 58.
- Animal transportation, 132.
- Antichlor, 240.
- Antipyrin, 259.
- Armature, 319, 320.
- Artificial lighting, 148-153.
- Atmosphere, 81.
- carbon dioxide in, 54-55.
- height of, 81.
- nitrogen and oxygen in, 262.
- pressure of, 82-86.
- water vapor in, 36-38.
- weight, 86.
- See Air.
- Atmospheric pressure, 82-86.
- Atomizer, 92.
- Atoms, 102.
- Automobiles, gas engines, 185.
- Axis of a lens, 119.
- Bacteria, 133.
- as nitrogen makers, 263.
- destroyed by sunlight, etc., 133, 250, 251.
- diseases caused by, 133.
- in butter and cheese, 133.
- Baking powder, 229-230.
- Baking soda, 227-229.
- Barograph, 87.
- Barometer, aneroid, 84-85.
- mercury, 84.
- use in weather predictions, 86-87.
- Bases, action on litmus, 221-222.
- Battery, electric, 311.
- Beans, as food, 66.
- roots take in nitrogen, 263.
- Bell, electric, 319-321.
- Benzine, 150.
- as a cleaning agent, 227.
- Benzoate of soda, 253.
- Bicarbonate of soda, in fire extinguisher, 55, 56.
- in Rochelle salt, 227.
- in soda mints, 231.
- in seidlitz powder, 231.
- Bicycle pumps, 202.
- Blasting, by electricity, 314.
- Bleaching, 237-243.
- Bleaching powder, 239-240.
- Body, human, 63-64.
- a conductor of electricity, 292.
- Boiling, 31.
- amount of heat absorbed, 31-32.
- of milk, 32.
- of water, 77.
- point, 15.
- Bomb calorimeter, 61.
- Borax, as meat preservative, 253.
- Boric acid, as meat preservative, 253.
- Boyle's law, 95-96.
- Bread, 232-233.
- Bread making, 232-235.
- Breathing, hygienic habits of, 50.
- Burns, treatment of, 52-53.
- Butter, adulteration test, 16.
- Buttermilk, 230.
- Caisson, 203-204.
- Calcium carbide, 152-153.
- in making nitrogenous fertilizer, 264.
- Calico printing, 249.
- Calorie, 27-28, 61-62.
- Calorimeter, 61.
- Camera, 128-129.
- Camping, water supply, 195-197.
- Candle, 148-149.
- as standard for light-measure, 104-105.
- Candle-power, 105-107.
- Carbide, calcium, 152-153, 264.
- Carbohydrates, 64-65, 149.
- Carbolic acid, 152.
- Carbon, 56, 66.
- in voltaic cells, 308.
- Carbon dioxide, 53.
- as fire extinguisher, 55-56.
- commercial use, 55-56.
- in baking soda, 228.
- in fermentation, 234.
- in health, 54.
- in plants, 55.
- preparation of, 55.
- source of, 53.
- test for, 228.
- Catarrh, 259.
- Caustic lime, 222..
- Caustic potash, 222.
- Caustic soda, 218, 222.
- Caves and caverns, 71.
- Cell, dry, 310.
- Cells of human body, 63, 64, 66.
- Centigrade thermometer, 15.
- Central heating plant, 19.
- Chalk, in making carbon dioxide, 55.
- Charcoal as a filter, 57.
- commercially, 57.
- preparation, 57-58.
- Chemical action, and electricity, 307, 315-317.
- Chemistry, in daily life, 218, 219.
- Chills, 38.
- Chloride of lime, in bleaching, 240.
- Chlorine, and hydrogen, 239.
- effect upon human body, 239.
- in bleaching, 238-240.
- influence of light upon, 126.
- presence in salt, 227.
- Circuit, electric, 321.
- City water supply, 206-212.
- Clarinet, 297.
- Cleaning of material, 226, 243.
- Climate, influenced by presence of water, 29, 40.
- Clover, nitrogen producers, 263.
- Coal, 30.
- Coal gas, 150, 151.
- Coal oil, 149, 150.
- Coal tar dyes, 152, 218, 245.
- Cogwheels, 170.
- Coil, current-bearing, 320.
- Coke, 152.
- Cold storage, 97.
- Color, 134-141.
- and heat, 142, 143.
- influenced by light, 137.
- of opaque bodies, 136, 137.
- of transparent bodies, 135, 136.
- Color blindness, 140, 141.
- Colors, compound, 138, 139.
- Combustion, heat of, 45.
- Commutator, 335.
- Compass, 328.
- Compound colors, 138, 139.
- Compound machine, 171.
- Compound substances, 103.
- Compression of air, 91, 92.
- Compression pumps, 201, 205.
- Concave lens, 118.
- Condensation, 33.
- Conduction of heat, 25.
- Conductivity metals, 321.
- Conductors, electric, 321, 322.
- Conservation, of energy, 58, 59.
- Convection, 24, 25.
- Convex lens, 118.
- Cooling, by evaporation, 35-36.
- Copper, in electric cell, 307.
- Core, iron, 319.
- Corn, bleached with sulphurous acid, 242.
- Cotton, mercerized, 218.
- Cough sirup, 258.
- Crane, compound machine, 172.
- Cream of tartar, 229.
- Creosote oil, 254.
- Crude petroleum, 149, 150.
- Current, electric, 306, 312.
- Dams, 214-216.
- Decay, 49.
- Decomposition of soil by water, 70-74.
- Degrees Fahrenheit and Centigrade, 15.
- Density, 11.
- Designs in cloth, printed, 248, 249.
- Developer in photography, 128.
- Dew, 36, 37.
- Dew point, 38.
- Diarrhea, 251.
- Diet, 62, 66.
- Discord, reason for, 271.
- Disease, and surface water, 76.
- Disease disinfectants, 250, 251, 252.
- Distillation, 34-35.
- Diving suits, 204.
- Door bells, 319-321.
- Drainage, of land, 194, 195.
- Drilled well, 199.
- Drinking water, 75-77.
- Driven well, 196-197.
- Drought, 217.
- Drugs, 255, 260.
- Dry cell, 312.
- Dyeing, 244-249.
- Dyeing, direct, 245.
- home, 247.
- indirect, 247.
- variety of color, 247.
- Dyes, 218, 244, 245.
- Dynamo, 346.
- alternating current, 349.
- source of energy, 346-347.
- Ear, in man, 301-303.
- Earth, conductor of electricity, 326.
- Echo, 277.
- Economy in buying food, 66-69.
- Effort, muscular, 155, 160.
- Electric, battery, 311.
- bell, 319-321.
- bread toasters, 314.
- conductors and non-conductors, 321-322.
- cost of, energy, 352.
- current, 306, 312.
- flatiron, 313.
- heating pad, 314.
- lights, 314.
- street cars, 337.
- Electricity, heat, 312-315, 339.
- Electrodes, of cell, 308.
- Electrolytic metals, 317.
- Electromagnets, 319.
- Electromotive force, 308.
- Electroplating, 315.
- Electrotyping, 317.
- Elements, 102-103.
- Emulsion, 224.
- Energy, conservation of, 58, 59.
- transformations of, 58, 59.
- Engine, steam, 183-185.
- Erosion, 73-74.
- Essential colors, 139-140.
- Evaporation, 35-39.
- cooling effect, 35-36.
- effect of temperature on, 35, 36.
- effect of air on, 38.
- freezing by, 98.
- heat absorbed, 36.
- of perspiration, 38.
- Expansion, of air, 10, 11.
- cooling effect of, 97.
- disadvantage and advantage of, 11-13.
- of liquids, 9-11.
- of solids, 10, 11.
- of water, 9, 10, 11, 12.
- Eye, 122-125.
- headache, 124, 125.
- how focused, 122, 123.
- nearsighted and farsighted, 123.
- strain, 125.
- Fahrenheit thermometer, 15.
- Fats, 65.
- Fermentation, 232-236.
- Ferric compounds, 248.
- Fertilizers, 262-265.
- Field magnet, 336.
- Filings, iron, 329.
- Film, photographic, 129.
- Filter, charcoal, 57.
- Filtering water, 77.
- Fire, 9.
- and oxygen, 45, 47.
- and tinder box, 47.
- making of, 51.
- primitive production of, 47.
- produced by friction, 47.
- spontaneous combustion, 52.
- sores and burns, 52-53.
- extinguisher, 55, 56.
- Fireless cooker, 25, 26.
- Fireplaces, 17, 18.
- Fixing, in photography, 128.
- Flame, hydrogen, 80.
- Flood, Johnstown, 214, 215.
- relation to forests, 217.
- Flour, self-raising, 231.
- Flume, 177.
- Flute, 297.
- Focal length, 118.
- Focus, of lens, 118.
- Fog, 37.
- Food, 60-69.
- carbohydrates, 64, 65.
- economy in buying, 66-69.
- fats, 65.
- fuel value of, 60-62.
- need of, 63, 64.
- preservatives, 252.
- proteids, 66.
- value, 67.
- waste, 60.
- water in, 75.
- Foot pound, 172.
- Force and motion, 156, 157.
- Force pumps, 192, 193.
- Forests and water supply, 216-217.
- Forging of iron, 40, 41.
- Formaldehyde, 253.
- Freezing, effect of salt, 44.
- effect on ground and rocks, 42.
- expansion of water on, 41.
- ice cream freezer, 44.
- Frequency in music, 273, 275.
- Fresh air, 22-24, 49.
- amount consumed by gas burner, 22.
- and health, 49, 50.
- in underground work, 202.
- in work under water, 203-205.
- Friction, 173, 174.
- losses by, 174, 210.
- source of heat and fire, 47.
- Frost, 36, 37.
- Fruit, canned, bleached with sulphurous acid, 242.
- colored with coal tar dyes, 253.
- Fuel value of foods, 60-62.
- table of fuel values, 67.
- Fulcrum, 159, 160.
- Fumigation, 251.
- Fundamental tone, 290, 291, 292.
- Furnace, hot air, 19.
- Fuse, 340.
- Fusion, heat of, 40.
- Galvanometer, 341.
- Gas, acetylene, 152, 153.
- and unburned carbon, 151.
- coal, 151, 152.
- effect of heat on volume, 96, 97.
- effect of pressure on volume, 95-96.
- engine, 185-186.
- for cooking, 151, 152.
- illuminating, 92, 93, 150, 151.
- liquefaction, 97, 98.
- meter, 93, 94.
- natural, 152.
- Gasolene, 149, 150.
- Gauge, pressure, 92-94.
- Gelatin, plate and film, 129.
- Glass, kinds of, 119.
- molding of, 40.
- non-conductor, 321.
- Grape juice, fermented with millet, 233.
- Gravity cell, 309, 310.
- Grease, and lye, 221.
- Gulf Stream, 24.
- Hard water, and soap, 225.
- Harp, 295.
- Headache, 124, 125.
- Health, effect of diet, 62, 64.
- Heat, 9.
- absorbed in boiling, 31-32.
- and disease germs, 250.
- and food, 252.
- and friction, 47.
- and light, 142, 147.
- and oxidation, 45, 48, 49.
- and wave motion, 145-147.
- conduction, 25.
- convection, 24, 25.
- from burning hydrogen, 80.
- from electricity, 312-315, 339.
- needed to melt substances, 39.
- of fusion, 40.
- of vaporization, 32.
- produced by compression, 96.
- relation of water to weather, 29, 40.
- set free by freezing water, 40.
- sources of, 29-30.
- specific, 28-29.
- temperature, 27.
- unit of, 27, 28.
- Heating effect of electric current, 312-315.
- Heating of buildings: central heating plant, 19.
- Heating, furnaces, 19.
- Helix, 318.
- Horse power, 173, 351.
- Hot water heating, 19-22.
- Hues, primary, 135.
- Humidity, 38.
- proper percentage for health and comfort, 38, 39.
- Humus, 216, 217.
- Hydrocarbons, 149.
- Hydrochloric acid, composition, 227.
- in bleaching, 241.
- to make a salt, 227.
- to make carbon dioxide, 55.
- to make chlorine, 238.
- to make hydrogen, 80.
- Hydrogen, 65, 66.
- and chlorine, 239.
- and water, 79.
- chemical conduct, 126-127.
- flame, 80.
- in voltaic cell, 307.
- peroxide, 53, 252.
- preparation, 80.
- to liquefy, 97.
- Ice, lighter than water, 42.
- Ice cream freezers, 44.
- Illuminating gas, manufacture of, 150, 151.
- measurement of quantity consumed, 93, 94.
- test of pressure, 92, 93.
- Illumination, intensity of, 105, 106.
- Image, in mirror, 108, 111.
- Incandescent lighting, 107, 314.
- Incidence, angle of, 110.
- Inclined plane, 162-166.
- Indigo, 218.
- Induced current, 346-347.
- Ink spots, removal of, 243.
- Insoluble substances, 71.
- Insulators, electric, 324.
- Intensity, of light, 105-107.
- Interval, in musical scale, 283.
- Iron, forging, 41.
- filings, 329.
- galvanizing, 49.
- oxidation of, 48.
- Irrigation, 193-194.
- Isobaric lines, 88, 91.
- Isothermal lines, 89, 91.
- Lactic acid, 230.
- Leaves, 132, 262.
- Lens, 117-121.
- concave, 118.
- converging, 118.
- crystalline, of eye, 122.
- focal length, 118.
- material, 119.
- refractive power, 119.
- Lever, 158-162.
- Life, and carbon dioxide, 54.
- and nitrogen, 261.
- and oxygen, 49, 54.
- Lifting pumps, 189-192.
- Light, absorption, 135-138.
- and heat, 142-147.
- a wave motion, 145-147.
- bent rays, 113, 114.
- chemical action, 126-127.
- disease, 131-132.
- essential to life, 131, 132.
- fading illumination, 105, 106.
- influence on color, 134.
- reflection of, 109-112.
- refraction of, 113-125.
- travels in a straight line, 108.
- white, composed of colors, 134.
- Lighting, artificial, 148-153.
- Lime, chloride of, 240, 251.
- Limewater, 220.
- Linen, bleaching, 241.
- Lines, of force, 329-331, 334.
- Liquefaction of gases, 97, 98.
- Liquid air, 98.
- Liquid soap, 223, 224.
- Litmus, action of acids, 220.
- action of bases, 221, 222.
- action of neutral substance, 222.
- Logwood dyes, 245, 247, 248.
- Los Angeles aqueduct, 211.
- Lye, 221, 222.
- Machines, compound, 171.
- Madder, for dyes, 245.
- Magnet, 328.
- Magnetic, needle, 328.
- Magnifying power, of a lens, 115.
- of a microscope, 115.
- of a telescope, 115.
- Mammoth Cave of Kentucky, 71.
- Manganese dioxide, 46.
- chlorine made from, 238.
- oxygen made from, 46.
- Marble, for carbon dioxide, 55.
- Matches, 47.
- Matching colors, 137.
- Matter, conservation of, 58, 59.
- Meat, 66.
- Mechanical devices, 154, 155.
- Melting, 39, 40.
- Melting point, 40.
- Melting substances without a definite melting point, 40.
- Mercerized cotton, 218.
- Mercury, barometer, 84.
- Metals, electroplating, 317.
- preservation by paint, 253-254.
- veins deposited by precipitation, 72, 73.
- welding, 315.
- Meter, gas, 93, 94.
- Microörganisms, 132, 133.
- Microscope, 115.
- Milk, boiling point, 32.
- Minerals, in foods, 62, 63.
- Mirrors, 108-112.
- distance of image behind mirror, 111.
- distance of object in front of mirror, 111.
- image a duplicate of object. 111.
- Molding of glass, 40.
- Molecule, 100-103.
- Mordants, 247, 248, 249.
- Morphine, 257.
- Morse, telegraphic code, 324.
- Motion, in sound, 266, 278, 280.
- Motor, electric, 336.
- principle of, 333.
- street car, 337.
- Mouth breathing, 50.
- Movable pulley, 167, 168.
- Music, 278.
- Musical instruments, percussion, 299.
- Musical scale, 282.
- Naphtha in gas engines, 185.
- Naphthalene, 152.
- Narcotics, 255.
- Natural gas, 152.
- Needle, magnetic, 328.
- Negative, electrode, 308.
- Neutral substance, 222.
- Neutralization, 222.
- Niagara Falls, 176.
- Nitrogen, 66.
- and bacteria, 263.
- and plant life, 261.
- in atmosphere, 261.
- in fertilizer, 262-265.
- in food, 66.
- preparation of, 261.
- properties of, 261.
- Noise in music, 280.
- Non-conductors, of electricity, 321-322.
- Nutcracker, as a lever, 162.
- Oboe, 297.
- Octave, 284.
- Odors, 101.
- Ohm, unit of resistance, 345.
- Oil, gasoline, 149, 150.
- Orchestra grouping, 299.
- Ore, 72.
- Organ pipes, 297.
- Overtones, 290-293.
- Oxalic acid, 247, 248.
- Oxidation, 45-59.
- and decay, 49.
- heat the result of, 49-52.
- in human body, 49, 53.
- of iron, 48.
- Oxygen, 66.
- and bleaching, 239.
- and combustion, 45.
- and food, 66.
- and plants, 55.
- and the human body, 50.
- and water, 79, 80.
- in the atmosphere, 45.
- preparation of, 46.
- Paint, as wood and metal preservatives, 253, 254.
- Paper making, 219.
- Paraffin, 150, 321.
- Pasteurized milk, 250.
- Patent medicines, 257-260.
- Peas, sources of nitrogen, 263.
- Pelton wheel, 177.
- Percussion instruments, 299.
- Period of a body, 273.
- Peroxide of hydrogen, 53, 252
- Petrolatum, 150.
- Petroleum, 149, 150.
- Phonograph, 303-305.
- Phosphorus, in fertilizer, 263, 264.
- in making nitrogen, 261.
- in matches, 47, 48.
- poisoning by, 47.
- Photography, 127-131.
- Photometer, 107.
- Pianos, 284-292.
- Pin wheel, 181.
- Pitch of sound, 280, 281.
- Plane, inclined, 162-166.
- Plants, and atmosphere, 55.
- Plate developing, photographic, 128.
- Pneumatic dispatch tube, 205.
- Poles, magnetic, 330-332.
- Positive electrode, 308.
- Potash, in fertilizer, 263-265.
- Potassium chlorate and oxygen, 46.
- permanganate, 100.
- tartrate and Rochelle salt, 227.
- Power, candle, 105-107.
- Precipitation, 72, 73.
- Preservatives, food, 252.
- Pressure, atmospheric, 82-86.
- calculation of atmospheric, 83, 84.
- calculation of gas, 92, 93.
- calculation of water, 94.
- gauge, 92-94.
- of illuminating gas, 93.
- relation of pressure of gas to volume, 95, 96.
- water pressure, 208-211, 214-216.
- within the body, 86.
- Primary colors, 135.
- Print, photographic, 131.
- Printing, color designs in cloth, 248, 249.
- Prisms, 135.
- Proteids, 66.
- Pulleys, 166-169.
- Pump, 187-205.
- Pupil of the eye, 122.
- Pure food laws, bleaching, 242.
- Purification of water, 77, 196.
- Push button, 321.
- Radiator, 19-21.
- Railroads, grading of, 165-166.
- Rain, 36, 37.
- Rainbow, 134.
- Rain water, 225.
- Reflection, angle of, 110.
- Refraction, angle of, 114.
- Relay, telegraph, 325.
- Reservoir, 214.
- Resistance, electrical, 312.
- internal, of cell, 343.
- unit of, 345.
- Resonance, 276.
- River, volume and value of, 180.
- Roads, application of inclined plane to, 165-166.
- Rochelle salt, 227, 231.
- Rocks, effect of freezing water on, 42-43.
- Rosin, obtained by distillation, 35.
- Safety matches, 47-48.
- Salicylic acid, 253.
- Salt, 227-228.
- Salts, 227.
- general properties, 227.
- in ocean, 227.
- smelling, 222.
- Saturation of air, 37.
- Scale, musical, 282.
- Screw, and inclined plane, 166.
- Seaweed, 265.
- Seidlitz powder, 231.
- Self-raising flour, 231.
- Sewage, disposition of, 198-199.
- of camps, 196.
- source of revenue, 201.
- Sewer gas, 57.
- Silk, bleaching, 241.
- Silver chloride, 127-131.
- Simple colors, 138.
- Simple substances, 103.
- Siren, 280.
- Smelling salts, 222.
- Snow, 36-37.
- Soap, 222-224.
- Soda, baking, 227, 228-229.
- Soda mints, 231.
- Sodium, bicarbonate, 56, 227, 228, 230-231.
- carbonate, 228.
- chloride, 228.
- Soil, deposited by streams, 73.
- Solenoid, 318.
- Solution, 70.
- Soothing sirup, 258.
- Sound, and motion, 266, 278.
- Sounder, telegraph, 324.
- Sounding board, 277.
- Sour milk in cooking, 230.
- Specific heat, 28-29.
- Spectrum, 134-135.
- Speed, of sound, 271, 272.
- Spontaneous combustion, 52.
- Stains, removal of, 226, 243.
- Standpipes, 212.
- Starch, 65.
- Steam, and work, 183-184.
- Steel, forging and annealing, 16.
- Stoves, 18-19.
- Streams, carriers of mud, 73.
- Street cars, electric, 337.
- Stringed instruments, 284-295.
- Strings, vibrating, 286-290.
- Sugar, 16, 65.
- Sulphur, 66.
- as disinfectant, 251.
- in making sulphurous acid, 242.
- Sulphuric acid, in bleaching, 240,241.
- in fire extinguisher, 55.
- in making of hydrogen, 80.
- in voltaic cell, 307.
- Sulphurous acid, in bleaching, 242.
- Sun, energy derived from, 143-144.
- Sunlight, 135.
- Sympathetic vibrations, 274-277.
- Tallow, 105, 148.
- Tartar, cream of, 229.
- Telegraph, 322.
- long distance, 327.
- relay, 325.
- sounder, 324.
- Telephone, 350-351.
- Temperature, 13-14.
- as measurement of heat present, 27.
- in detecting adulterants, 17.
- in forging steel, 16.
- in making sirups, 16.
- measurement of, 14-15.
- Thermometer, 14-17.
- Centigrade, 15.
- Fahrenheit, 15.
- Tinder box, 47.
- Transmission, of light, 145-147.
- Tuning fork, 266, 273, 278, 290.
- Turbine, steam, 183.
- Turpentine, and grease, 226.
- Vacuum, sound in, 268.
- Vapor, in atmosphere, 36-38.
- Vaporization, heat of, 32.
- Varnish, on candies, 253.
- Vegetable matter, and coal, 30.
- and gas, 30.
- and oil, 30.
- Veins, formation in rock, 72-73.
- Velocity, of sound, 271-272.
- Ventilation, 21-24, 54.
- Vibration, of strings, 286-290.
- Viola, 295.
- Violin, 295.
- Violoncello, 295.
- Vocal cords, 300.
- Voice, 300.
- Volt, 344.
- Voltage, 345.
- Voltaic cell, 306-308, 310.
- Voltmeter, 344.
- Volume, of a stream, 179-180.
- relation of pressure of a gas, 95-96.
- Washing powders, 224-226.
- Water, action in nature, 70-74.
- amount used daily per person, 181.
- and hydrogen, 79.
- and oxygen, 79, 80.
- as solvent, 70-71.
- boiling, 77.
- boiling point, 15.
- composition, 79-80.
- condensation, 33.
- dams and reservoirs, 214-216.
- density, 11.
- distilled, 34, 77.
- drinking, 75-77, 195-201.
- electrolysis, 79-80.
- evaporation, 33-34.
- expansion, 9-10, 41-42.
- filtration, 77.
- freezing, 40-41.
- hard, 225.
- heat of fusion, 40.
- impurities, 76-77.
- in atmosphere, 36-38.
- in food, 75.
- in human body, 75.
- in vegetables, 75.
- influence on climate, 29, 40.
- irrigation, 193-194.
- minerals in, 70-71.
- ocean, 265.
- power, 176-180.
- precipitates, 72, 73.
- pressure, 208-211, 214-216.
- purification, 77.
- rain, 225.
- running, value of, 178-180.
- source of, 78.
- steam, 32.
- waves, 145-147.
- weight, 208-209, 215.
- wells, 195-201.
- wheels, 176-180.
- work under, 203-205.
- Water supply, and forests, 216-217.
- Watt, 351.
- Waves, heat, 145-147.
- Weather, bureau, 87-91.
- Weather maps, 89-91.
- Wedge, and inclined plane, 166.
- Weight, of air, 86.
- Welding, by electricity, 315.
- Wells, 195-201.
- Wheel and axle, 169-171.
- cogwheels, 170.
- windlass, 169.
- Wheelbarrow as lever, 160-161.
- White light, nature of, 135.
- Wind instruments, 297-301.
- Windlass, 169.
- Windmill, 174-175, 180-182.
- Winds, 24.
- Wine, 232, 234.
- Wood, as source of charcoal, 58.
- ashes in soap making, 223.
- in paper making, 219.
- preservation, 253-254.
- Wool, bleaching, 241.
- Work, 156-186.
- Woven designs in cloth, 249.
- Zinc, in galvanizing iron, 49.
- in making hydrogen, 80.
- in voltaic cell, 307-308.