II THE PROBLEMS OF THE DEEP SEA 67 



is much greater than that from the Atlantic under 

 corresponding parallels ; secondly, that the rainfall 

 over the Mediterranean makes up for evaporation 

 less than it does over the Atlantic ; and thirdly, 

 supposing these two questions answered affirm- 

 atively : Are not these sources of loss in the 

 Mediterranean fully covered by the prodigious 

 quantity of fresh water which is poured into it by 

 great rivers and submarine springs ? Consider 

 that the water of the Ebro, the Rhine, the Po, the 

 Danube, the Don, the Dnieper, and the Nile, all 

 flow directly or indirectly into the Mediterranean ; 

 that the volume of fresh water which they pour 

 into it is so enormous that fresh water may some- 

 times be baled up from the surface of the sea off 

 the Delta of the Nile, while the land is not yet in 

 sight ; that the water of the Black Sea is half fresh, 

 and that a current of three or four miles an hour 

 constantly streams from it Mediterraneanwards 

 through the Bosphorus; consider, in addition, 

 that no fewer than ten submarine springs of fresh 

 water are known to burst up in the Mediterranean, 

 some of them so large that Admiral Smyth calls 

 them " subterranean rivers of amazing volume and 

 force " ; and it would seem, on the face of the 

 matter, that the sun must have enough to do to 

 keep the level of the Mediterranean down ; and 

 that, possibly, we may have to seek for the cause 

 of the small superiority in saline contents of the 

 Mediterranean water in some condition other than 

 solar evaporation. 



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