INDEX 



607 



Thunderstorm, 240. 

 Top-icing refrigerator, 155. 

 Tornado, 244; effects of, 246; and 



cyclone contrasted, 247. 

 Torricelli's experiment, 182. 

 Toxine, 433. 

 Trap, the, 506. 

 Tuberculosis, 441 ; bacillus of, 442 ; 



and occupation, 443; curable, 



444. 



Turbine, water wheel, 560. 

 Typhoid, fever, 439; carrier, 440. 



Underfeed furnace, 99. 

 Undershot water wheel, 558. 



Vaccination, 426, 428. 



Vaccine, 427. 



Vacuum, gauge, 136; system of 

 heating, 140; valve, 140; system, 

 advantage of, 142; cleaning, 338. 



Valve, vacuum, 140; safety, 136, 

 574; float, or automatic cut off, 

 508. 



Van Leeuwenhoek, 397. 



Vapor, of candle, 4; kerosene, 8; 

 paraffin, 5; water, 16, 212; con- 

 densation of, 224, 225. 



Vaporizing, 15, 131. 



Ventilation, 311; need of, 311; 

 theories regarding, 312; amount 

 of air required for, 316; relation 

 of humidity to, 316; effect of air 

 movements upon, 320; ideal 

 indoor air, 319; in colonial days, 

 328; of modern dwellings, 329; 

 of the one-room school, 331; 

 plenum system of, 333. 



Vernier, 186. 



Vibrating shuttle, 525. 



Vitiated air, 312, 327. 



Water, -gas, 102; man's dependence 

 upon, 450; ground, 453; table or 

 plane, 454; vein of, 470; "witch- 

 ing" for, 471; artesian, 472; 

 city systems of, 482; amount of 

 used, 483; front, or back, 500; 

 pressure gauge, 495; meter, 495; 

 wheels, 557. 



Water meter, 495; construction of, 

 496; reading of, 497. 



Water power, source of, 562; 

 amount available 563; distri- 

 bution of, 563. 



Water systems, 482; publicly and 

 privately owned, 482; source of 

 supply for, 484; development of, 

 485; of New York City, 486; of 

 Los Angeles, 488; deep-well sup- 



Ely, 488; under pressure, 489; 

 ead of, 491; for country resi- 

 dence, 478; for hot water, 499. 



Water wheels, kinds of, 557; over- 

 shot, 557; breast, 558; under- 

 shot, 558; impulse, 558; turbine, 

 560. 



Watt, the, 69; -hour, 69. 



Watt's engine, 568; how it worked, 

 571; double acting, 571. 



Weather, 176-288; defined, 176, 

 288; cause of, 177; instruments, 

 179; making the map of, 250; 

 causes of unusual, 267; resulting 

 from lows and highs, 268; rela- 

 tion to sun's migration, 277. 



Weight, 536; how determined, 537; 

 compared with force, 539. 



Wells, and the water table, 454; 

 and a vein of water, 470; deep 

 and shallow, 472; artesian, 472; 

 shallow wells often dangerous, 

 481; protecting shallow wells, 

 482. 



Westerlies, 277. 



Wheat, 369; flour, 369; shredded, 

 370; spring, and winter, 369. 



W r hey, 365. 



Whooping cough, 447. 



Wind, 298; map of velocities, 299; 

 caused by unequal pressure, 251 ; 

 velocity of, 252; effect on tem- 

 perature, 252; how it shifts 

 with a low, 258; law of, 259; 

 about an elliptical low, 260; 

 -barometer indications, 261 ; path 

 of, 265; deflection of, 275; land 

 and sea, 278. 



Wood, burning of, 89. 



Work, 540; units of, 540; equiva- 

 lent in calories of heat, 551. 



Working stroke of gasoline engine, 

 578. 



Xerophytes, 466. 



Yeasts, 383-389; fermentation by, 

 391; and bread, 394; and liquors, 

 394; wild and cultivated, 395. 



