200 PHYSICAL GEOGRAPHY OF THE SEA, AND ITS METEOROLOGY. 



are left to conjecture no longer, but are furnished ^Yitll evidence and 

 proof the mo3t convincing and complete that the sea is salt from a 

 physical necessity. 



499. Thus beholding sea-shells and animalculae, may we not 

 Sea-shells and aiii- now ccasc to reo'ard them as beings which have little 



iiialculaj in a new ,. jt* • i • • n ^ • p 



light. or notnnig to do m mamtammg the harmonies oi 



creation ? On the contrary, do we not see in them the principles 

 of the most admirable compensation in the system of oceanic circu- 

 lation ? We may even regard them as regulators, to some extent, 

 of climates in parts of the earth far removed from their presence. 

 There is something suggestive, both of the grand and the beautiful, 

 in the idea that, while the insects of the sea are building up their 

 coral islands in the perpetual summer of the tropics, they are also 

 engaged in dispensing warmth to distant parts of the earth, and in 

 mitigating the severe cold of the polar winter. Sm^ely an hypo- 

 thesis which, being followed out, suggests so much design, such 

 perfect order and arrangement, and so many beauties for contempla- 

 tion and admiration as does this, which, for want of a better I have 

 ventured to ofi'er with regard to the solid matter of the sea water, 

 its salts and its shells — surely, I say, such an hypothesis, though it 

 be not based entirely on the results of actual observation, cannot 

 be regarded as wholly vain or as altogether profitless. 



CHAPTEE XI. 



§ 501-526. THE CLOUD REGION, THE EQUATORIAL CLOUD- 

 RING, AND SEA FOGS. 



501. To simplify the discussion of these phenomena, let us con- 

 cioud region-high- sidcr fogs at sea to be in character like clouds m the 

 est in the calm belts, g]^^^ g^ treating them, and confining om- attention 

 to them as they appear to the mariner, we discover that the cloud ^ 

 region in the main is highest in the trade-wdnd and calm belts, 

 lowest in extra-tropical regions. 



502. At sea, beyond "the offings," fogs are not often seen be- 



Fogiess regions, twccu the parallels of 30° N. and S. Sea fogs, 



therefore, may be considered a rare phenomenon over one half of 



the surface of the globe. These fogless regions, though certain 



parts of them are not unfrequently visited by tempests, tornadoes, 



