-^yjii CONTENTS. 



CHAPTER IV. 



RED FOGS AND SEA DUST. 



Where found, ^ 157. — Tallies on the Wind, 158. — Where taken up, 160. — Hum- 

 boldt's Description, 163. — Information derived from Sea Dust, 165. — Its Bearings 

 upon the Theory of Atmospherical Circulation, 167. — Suggests Magnetic Agency, 

 170 • Page 97 



CHAPTER V. 



ON THE PROBABLE RELATION BETWEEN MAGNETISM AND THE CIRCULATION OF THE 



ATMOSPHERE. 



Reasons for supposing that the Air of the Northeast and of the Southeast Trades 

 cross at the calm Belts, ^ 174. — What Observations have shovs^n, 184. — Physical 

 Agencies not left to Chance, 188. — Conjectures, 192. — Reasons for supposing that 

 there is a crossing of Trade-wind Air at the Equator, 194. — W^hy the extra-trop- 

 ical Regions of the Northern Hemisphere are likened to the Condenser of a Steam- 

 boiler in the South, 199.— -Illustration, 200.— A Coincidence, 202.— Proof, 203.— 

 Nature affords nothing in contradiction to the supposed System of Circulation, 204. 

 Objections answered, 205. — Why the Air brought to the Equator by the Northeast 

 Trades will not readily mix with that brought by the Southeast, 207. — Additional 

 Evidence, 209. — Rains for the Mississippi River are not supplied from the Atlan- 

 tic, 210.— Traced to the South Pacific, 213.— Anticipation of Light from the Polar 

 Regions, 216. — Received from the Microscope of Ehrenberg, 217, and the Exper- 

 iments of Faraday, 219. — More Light, 221. — W'hy there should be a calm Place 

 near each Pole, 222. — Why the Whirlwinds of the North should revolve against 

 the Sun, 223. — ^Vhy certain Countries should have scanty Rains, 228. — Magnetism 

 the Agent that causes the Atmospherical Crossings at the calm Places, 231 . . 104 



CHAPTER VI. 



CURRENTS OF THE SEA. 



Currents of the Sea : Governed by Laws, ^ 232. — The Inhabitants of the Sea the 

 Creatures of Climate, 233. — The Currents of the Sea an Index to its Climates, 235. 

 — First Principles, 236. — Some Currents run up hill, 237. — Currents of the Red 

 Sea, 238. — Top of that Sea an inclined Plane, 240. — How an under Current from 

 it is generated, 245. — Specific Gravity of Sea Waters, 248. — Why the Red Sea is 

 not salting up, 251. — Mediterranean Currents : How we know there is an un- 

 der Current from this Sea, 252. — The sunken W^reck which drifted out, 253. — Both 

 Currents caused by the Salts of the Sea, 254. — Currents of the Indian Ocean : 

 Why immense Volumes of warm Water flow from it, 255. — A Gulf Stream 

 along the Coast of Chhia, 256. — Points of Resemblance between it and the Gulf 

 Stream of the Atlantic, 257. — A Current into Behring's Strait, 258. — Geographical 

 Features unfavorable to large Icebergs in the North Pacific, 260. — Necessity for 

 cold to restore the Waste by the warm Currents, and Evaporation, 261. — Argu- 

 ments in favor of return Currents, because Sea Water is salt, 262. — Currents or 

 the Pacific : Its Sargasso Sea, 264. — The Drift on the Aleutian Islands, 265. — 

 The cold China Current, 266. — Humboldt's Current, 267. — Discovery of an ini- 



