66 THE PHYSICAL GEOGRAPHY OF THE SEA. 



CHAPTER III. 



THE ATMOSPHERE. 



The Relation of the Winds to the Physical Geography of the Sea, ^ 88. — No Expres- 

 sion of Nature without Meaning, 93. — The Circulation of the Atmosphere, Plate I., 

 95. — Southeast Trade-wind Region the larger, 109. — How the Winds approach the 

 Poles, 112. — The Offices of the Atmosphere, 114. — It is a powerful Machine, 118. — 

 Whence come the Rains that feed the great Rivers'? 120. — How Vapor passes 

 from one Hemisphere to the other, 123. — Evaporation greatest about Latitude 17°- 

 20°, 127. — Explanation, 128. — The Rainy Seasons : how caused, 129. — Why there 

 is one Rainy Season in California, 130 — One at Panama, 131 — Two at Bogota, 

 132. — Rainless Regions explained, 135. — Why Australia is a Dry Country, 136. — 

 Why Mountains have a dry and a rainy Side, 137. — The immense Fall of Rain 

 upon the Western Ghauts in India: how caused, 139. — Vapor for the Patagonia 

 Rains comes from the North Pacific, 141. — The mean annual Fall of Rain, 144. — 

 Evaporation from the Indian Ocean, 146. — Evidences of Design, 148. 



88. A PHILOSOPHER of tlio East,* with a richness of imagery 

 truly Oriental, describes the atmosphere as " a spherical shell 

 which surrounds our planet to a depth which is unknown to us, by 

 reason of its growing tenuity, as it is released from the pressure 

 of its own superincumbent mass. Its upper surface can not be 

 nearer to us than fifty, and can scarcely be more remote than five 

 hundred miles. It surrounds us on all sides, yet we see it not ; 

 it presses on us with a load of fifteen pounds on every square inch 

 of surface of our bodies, or from seventy to one hundred tons on 

 us in all, yet we do not so much as feel its weight. Softer than 

 the softest down — more impalpable than the finest gossamer — it 

 leaves the cobweb undisturbed, and scarcely stirs the lightest 

 flower that feeds on the dew it supplies ; yet it bears the fleets of 

 nations on its wings around the world, and crushes the most re- 

 fractory substances with its weight. When in motion, its force is 

 sufficient to level the most stately forests and stable buildings 

 with the earth — to raise the waters of the ocean into ridges like 

 mountains, and dash the strongest ships to pieces like toys. It 

 warms and cools by turns the earth and the living creatures that 

 mhabit it. It draws up vapors from the sea and land, retains 

 * Dr. Buist, of Bombay. 



