INDEX 



357 



Mt. Orizaba, 174 

 Mt. Ranier, 174, 177 

 Mt. Shasta, 174 

 Mountain breezes, 250 

 Mountains* 5, 11 



habitability of, 13 

 Mountains in history, 13 

 Mountains, origin of, 13 

 Movement of cyclones, 293 

 Movement of glaciers, 108 

 Movements of sea-water, 332 



Narrows, 78 



Narrows of Baraboo River, 79 



Natural bridges, 77 



Natural levees, 86 



Neap tides, 342 



Niagara Falls, 76, 77 



Nile, delta of, 96 



Nimbus clouds, 258, 259 



Nipissing Lakes, 139 



Nitrogen of air, 221, 222 



North America, ice-sheet of, 130, 132 



North Magnetic Pole, 202 



Northers, 294 



Ocean, 323 



Ocean basins, 3 



Ocean currents, 334 



Ocean currents and drifts, 44, 334 



Ocean currents, cause of, 337 



climatic effects of, 337 

 Ocean, depth of, 324 

 Oceanic climate, 310, 312, 313 

 Old topography, 73 

 Old valley, 72 

 Ooze, 349 

 Orbit of earth, 206 

 Outwash plain, 126, 127 

 Oxbow lakes, 88 

 Oxygen of air, 221, 222 



Palisade Ridge, 114, 180 

 Parallels, 207 

 Parry Island, 174 

 Permanent streams, 52, 69 

 Petrified wocd, 42 

 "Petrified forests," 322 

 Physiography and geography, 1 

 Physiography and geology, 1 

 Physiography defined, 1 

 Piedmont alluvial plain, 85 

 Piedmont glaciers, 106, 113 

 Piedmont Plateau, 11 

 Piracy, 67 



Piracy of streams, 82 

 Plains, 5 



alluvial, 85 ' 



coastal, 6 



habitability of, 9 



interior, 6, 9 



lacustrine, 147 



origin of, 10 



outwash, 126, 127 

 Planetary winds, 274 

 Planets, 216 

 Plants in the sea, 343 

 Plateaus, 5, 10 



habitability of, 11 



origin of, 11 

 Polar circles, 216 

 Polar zones, 311 



climate of, 318 

 Ponding of streams, 82 

 Precipitation, 29, 253, 259, 277 



amount of, 253 



for the world, 280 

 Prevailing winds, 274 



Races, tidal, 343 

 Radiation, 230 

 Rain, 259 

 Rainbows, 303 

 Rainfall, 277 



and agriculture, 319 



distribution of, 260, 278 



in zone of trades, 278 



in zones of westerlies, 279 

 Rain-making, 261 

 Rain-water, fate of, 29 

 Range of temperature, daily. 248 



seasonal, 248 

 Rapids, 76, 77 

 Ravines, 52 

 Red clay, 349 

 Red River lakes, 100 

 Reefs, 155 



Rejuvenation of streams, 82 

 Relative humidity, 255 

 Relief and relief features of land, 3 



of sea bottom, 325 

 Revolution of earth, 206 

 Rise of coast lands, 182 

 River lakes, 99 

 River system, 72 

 Rivers and rainfall, 51 

 Rivers and valleys, 59 

 Rivers, erosion by, 53, 57 



ice in, 102 



load of, 56 



