188 THE PHYSICAL GEOGRAPHY OF THE SEA. 



the depths of the sea, and a system of circulation between differ- 

 ent seas of the waters only that float above the shoalest reefs and 

 barriers. If the water in the depths of the sea were to be con- 

 fined there, doomed to everlasting repose, then why was it made 

 fluid, or why was the sea made any deeper than just to give room 

 for its surface currents to skim along? If water once below them 

 must remain below them — and they are shallow — ^why were the 

 depths of the ocean filled with fluid instead of solid matter? 

 Doubtless, when the seas were measured and the mountains stood 

 in the balance, the solid and fluid matter of the earth were adjust- 

 ed in exact proportions to insure perfection in the terrestrial ma- 

 chinery. I do not believe in the existence of any such imperfect 

 mechanism, or in any such failure of design as the imparting of 

 useless properties to matter, such as fluidity to that which is 

 doomed to be stationary would imply. To my mind, the proofs 

 — ^the theoretical proofs — the proofs derived exclusively from rea- 

 son and analogy — are as clear in favor of this under current from 

 the Mediterranean as they were in favor of the existence of Le- 

 verrier's planet before it was seen through the telescope at Berlin. 

 Now suppose, as Sir Charles Lyell maintains, that none of these 

 vast quantities of salt which this surface current takes into the 

 Mediterranean find their way out again. It would not be diffi- 

 cult to show, even to the satisfaction of that eminent geologist, 

 that this indraught conveys salt away from the Atlantic faster 

 than all the fresh-watev streams empty fresh supplies of salt into 

 the ocean. Now, besides this drain, vast quantities of salts are 

 extracted from sea water for coral reefs, shell banks, and marl 

 beds ; and by such reasoning as this, which is perfectly sound and 

 good, we establish the existence of this under current, or else we 

 are forced to the very unphilosophical conclusion that the sea 

 must be losing its salts, and becoming less and less briny. 



890. The Currents of the Indian Ocean. — By carefully 

 cuREENTs OF TUE in- cxamiuing the physical features of this sea (Plates 

 DiAN Ocean. Ylll. and IX.), and studying its conditions, we are 



led to look for warm currents that have their genesis in this 

 ocean, and that carry from it volumes of overheated water, prob- 

 ably exceeding in quantity many times that which is discharged 

 by the Gulf Stream from its fountains (Plate YI.). The Atlantic 

 Ocean is open at the north, but tropical countries bound the In- 



