270 PHYSICAL GEOGRAPHY OF THE SEA, AND ITS METEOEOLOGY. 



ture of the most ancient inhabitants of the deep, comparing their 

 physiology with that of their kindred in the fossil state, we are 

 left to conjecture no longer, but are furnished with evidence and 

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

 physical necessity. 



499. Sca-shclls and animalculcB in a new light. — Thus beholding 

 sea-shells and animalcule, may we not now cease to regard them 

 as beings which have little or nothing to do in maintaining the 

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

 the principles of the most admirable compensation in the system 

 of oceanic circulation ? AYe 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 disiDcnsing wannth to distant 

 parts of the earth, and in mitigating the severe cold of the polar 

 winter. Surely an hypothesis which, being followed out, suggests 

 so much design, such perfect order and arrangement, and so many 

 beauties for contemplation and admiration as does this, which, for 

 want of a better, I have ventured to offer 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 alto- 

 gether profitless. 



CHAPTEK XI. 



§ 501-526. THE CT.0UD P.EGIOX, THE EQUATOPJAL CLOUD 



RING, AND SEA FOGS. 



501. Cloud region — highest in the calm belts. — To simplify the 

 discussion of these phenomena, let us consider fogs at sea to be 

 in character like clouds in the sky. So treating them, and con- 

 fining our attention to them as they appear to the mariner, we 

 discover that the cloud region in the main is highest in the 

 trade-wind and calm belts, lowest in extra-troj)ical regions. 



502. Pogless regions. — At sea, beyond "the offings," fogs are 

 not often seen between the parallels of 30° N. and S. Sea fogs, 

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



