xii MAPS AND ILLUSTRATIONS 



PAGE 



Blue Hill Observatory, Milton, Massachusetts . . . .96 



Strato-Cumulus Clouds 103 



Fog 105 



A Great Siphon in the Los Angeles Aqueduct . . . . . 119 



A Modern Street Sweeper 121 



Pressure Cooker 126 



Mercurial Barometer 129 



Aneroid Barometer 130 



Barograph 130 



Observation War Balloons 132 



Bomb Burst by Freezing Water . 138 



Montezuma's Well 140 



Settling Basins of the St. Louis Water Plant 143 



A Limestone Cave 144 



An American Submarine 150 



A Submarine Submerging 151 



Corals . 152 



" Airing " an Aquarium . . 153 



Mount Everest 154 



Crinoid . . . 155 



Ocean Waves 158 



Fingal's Cave . . . . 159 



A Lake Beach, Formed by a Stream and Wave Action . . . 160 



A Sand Spit, Formed by Waves and Currents ..... 161 



Ocean Currents of the World ' . . 163 



High Tide in Nova Scotia ....'..... 164 



Low Tide at the Same Place . . . . . . . 165 



Mining Salt in the Dried up Salton Lake, California . . . 173 



Lake Drummond 174 



Gullies Being Cut by Running Water 175 



Divides between Streams 176 



Niagara Falls . .177 



Stream Working Back into an Undissected Area .... 178 



Yellowstone River 179' 



Platte River 180 



River Erosion 181 



Bottom Lands 182 



Stream Meandering on its Flood Plain 183 



Oxbow Lakes .184 



Levee along Lower Mississippi ........ 184 



An Old River 185 



River Terraces, Norway . . 187 



Intrenched Meander 188 



