INDEX 



References are to pages 



Cribs ^intakes) . . . , -. . 204 



Crustaceans (shellfish) , . . 533 



Cultivation ; see Soils 



Currents . . 110-111,161-162,484 



of air . . 110 



of electricity 484 



of water 161-162 



Cylinder (of engine) .... 471 



Darwin (on earthworm) . . . 319 



Day and night . . 3, 12, 24-26, 33 



variations in length of . . 24-26 



Daylight saving .... 37, 40, 362 



Decay 303, 315 



necessary in soil-making . . 315 



process of 303 



see also Bacteria ; Molds ; 



Protozoa ; Yeasts 



Declination (of earth) . . . 478 

 Degrees (of latitude and longi- 

 tude) ........ 32 



prime meridian (Greenwich) 32 



Deltas 189-190,549 



Density . 66, 94, 116, 132, 137, 150 

 of air ....... 116, 132 



of water 137 



Deposition and erosion 252, 278-282 



Dew 104 



Dew-point .... 102-104, 112 

 Diameter (of earth) ... 2, 23, 39 



Diaphragm 409 



Diastase 383 



Diatoms 532 



Dicotyledons 375-377 



Digestion (of food) . . . 419-421 

 alimentary canal . . . 419-421 



esoph'agus 420 



intestines 420-421 



mouth 420 



stomach 420 



Diphtheria (bacterial disease) . 442 



Direction (four cardinal points) 20, 24 



Disease . 361-362,401,441-449, 



452-455, 457 



antitoxins 444 



bubonic plague 454 



causes of 454 



bacteria. . 401,441-449,457 

 protozo'a . 400, 452-455, 457 



Disease Continued 



disinfection . 361-362, 443-445 



malaria 452 



prevention of . 361-362, 442-447 

 " sleeping sickness " of Africa 452 



source of 443-447 



Texas fever 454 



toxins 444 



typhoid fever 442 



wound-infection 442 



yellow fever 452 



see also Health and Sanitation 

 Disinfection . . 361-362,443-445 



air 445 



chloride of lime 445 



drying 444 



soap 445 



solutions 444-445 



sunlight 444-445 



temperatures, extremes of . 444 



water 445 



see also Health and Sanitation 

 Ditching (in irrigation) . . . 331 



Divides, land 175-176 



Doldrums 221 



Drainage ; see Soils 



Drowned river valleys . . 188-189 



Dry farming 329 



Dunes, sand 258, 283 



Dust (volcanic) 283-285 



Dynamo . . . ....'.- . . . 497 



Ear (organ of hearing) 416-418, 423 



auditory nerve 418 



bones of 418 



drum of 418 



Earth (a planet) .... 20-41 

 air and atmosphere ; see Air 

 axis and poles of . 8, 9, 25-31, 39 

 centrifugal and centripetal 



forces . . 43-49,58,93,326 

 circumference of . . . . 2, 23, 39 



climate 238-246 



clouds and precipitation . .102, 

 104, 133-134, 210, 215, 244, 483 

 coasts ; see, below, shores 



composition of 42 



continents and islands . . . 248, 

 256-276, 540-541 



