INDEX 



601 



Cyclones, 260, 276; vs. tornadoes, 



'247. 

 Cylinder, 580; purpose of several 



on automobiles, 580; heated on 



Watt's engine, 570. 



Day, length of, 284, 286. 



Decay, 399, 412 ; prevention of by 

 canning, 416; prevention of by 

 refrigeration, 154. 



Denitrifying bacteria, 408. 



Dew, 224; formation of, 224; false, 

 224; and ground-air, 462. 



Dew-point, 169; and fall of tem- 

 perature at night, 221 ; Table of, 

 222; curve of vs. temperature, 

 223. 



Dextrin, 373, 349. 



Dextrose, 373, 349. 



Digestion by molds, 385. 



Diphtheria, 431; toxine of, 433; 

 antitoxine of, 433; prevention of, 

 436. 



Direct radiation, 330. 



Direct-indirect radiation, 331. 



Diseases, theories of, ancient, 422 ; 

 semi-scientific, 422. 



Disinfectant, 415. 



Distillation, 21 ; of alcohol, 21, 391 ; 

 of petroleum, 23; of wood, 90; of 

 soft coal, 94. 



Drainage through the^ soil, 458; 

 purpose of soil drainage, 461. 



Drains, 504; venting of, 505; the 

 trap of, 506; subsurface, 515. 



Dry air, in refrigerator, 160; effect 

 of on foods, 160; evil effect on 

 health, 323; requires high tem- 

 perature, 323. 



Duct, cold air, 124. 



Dust, dangers of, 336; live and 

 dead, 337; house dust, 337; how 

 disposed of, 339. 



Earth's breathing, inhalation, 462; 



exhalation, 462; causes of, 463; 



effect on soil moisture, 463. 

 Efficiency of machines, 546; how 



measured, 546. 

 Efficiency of motors, 550. 

 Electric current, heating effect of, 



50. 

 Electric lighting, 50; incandescent 



lamp, 51; arc lamp, 52; co.st of, 

 69. 



Electric wiring, 53. 



Elements, chemical, 76; food, 345. 



Elliptical lows, 260. 



Energy, 77, 546, 549; chemical, 78; 

 kinetic, 77; potential, 77; elec- 

 trical, 77; conservation of, 78; 

 meaning of, 549; source of all, 

 562; losses of in motors, 581. 



Engine, steam, 565-574; gas, 574; 

 gasoline, 575; many cylindered, 

 580; Newcomen's, 567; Watt's, 

 568; modern steam, 572. 



Enzyme, 385, 392. 



Evaporation, 9, 15, 212; effect of 

 extent of surface, 10; effect of 

 temperature, 10; effect of air 

 currents, 10; of different liquids, 

 10; laws of, 11; defined, 15; how 

 controlled, 214, 465; effect on 

 personal comfort, 215; effect on 

 industries and materials, 216; 

 average rate of, 456; map, mean 

 annual, 213; measurement of, 

 214. 



Evaporator, sugar, 375. 



Explosive mixtures, of hydrogen, 

 87; of gasoline gas, 103; of 

 acetylene, 50. 



Factory, the coming of, 519; ice, 

 163. 



Fahrenheit scale, 14; to change to 

 centigrade, 17. 



Fallowing, 405. 



Fats, 348; vaporization of, 4 ^flash- 

 ing point of, 4; burning point of, 



Fermentation, 393; and bread 

 making, 395; alcoholic, 393; 

 butyric, 393; lactic, 393; pro- 

 tein, 394; and the refrigerator, 

 154. 



Ferments, 393. 



Ferrel's law, 274; application to a 

 low, 275; application to general 

 circulation, 273. 



Filter bed, 516. 



Filtering city water, 484. 



Fire, discovery of, 1; importance 

 of, 71; 100 years ago, 71. 



Fire hydrant, 492; drip of, 494. 



