CURRENTS OF THE OCEAN. 3 1 



regions, carrying supplies of cold water to modify the climate and 

 restore the equilibrium in that part of the world. This cold current 

 turns at first towards the west, then towards the south in the direction 

 of Madagascar ; more to the south still it is driven back by the polar 

 current from Cape Horn. It is thus that the warm waters from the 

 Bay of Bengal, pressed by the Indian polar current, circulate between 

 Africa and Australia, one lateral branch of the current sweeping along 

 the south coast of this vast continent. The monsoons which reign in 

 the Indian Ocean tend still more to complicate the currents, already 

 sufficiently intricate and confused. 



We have already spoken of a submarine current which appears to 

 carry the waters of the Mediterranean into the Atlantic Ocean. Its 

 existence is in some respects established by calculations which prove 

 that the quantity of salt water supplied by the upi)er current through 

 the Straits of Gibraltar is equal to seventy-two cubic miles per annum, 

 while the quantity of fresh water brought down by the rivers is equal 

 to six, and the quantity lost by evaporation to twelve cubic miles per 

 annum. This would leave an annual excess of sixty-six cubic miles, 

 if the equilibrium was not re-established by an under current flowing 

 into the Atlantic. This hypothesis would appear to have been 

 confirmed by a very curious fact. 



Towards the end of the seventeenth century a Dutch brig, pursued 

 by the French corsair Fhcenix, was overhauled between Tangier and 

 Tarifa, and seemed to be sunk by a single broadside ; but, in place of 

 foundering and going down, the brig, being freighted with a cargo of 

 oil and alcohol, floated between the two currents, and drifting towards 

 the west, finally ran aground, after two or three days, in the neigh- 

 bourhood of Tangier, more than twelve miles from the spot where she 

 had disappeared under the waves. She had therefore traversed that 

 distance, drawn by the action of the under current in a direction 

 opposite to that of the surface current. This ascertained fact, added 

 to some recent experiments, lends its support to the opinion which 

 admits of the existence of an outward current through the Straits of 

 Gibraltar. Dr. Maury quotes an extract from the " log" of Lieutenant 

 Temple, of the United States Navy, bearing the same inference. At 

 noon on the 8th of March, 1855, the ship Levant stood into Almeira 

 Bay, where many ships were waiting for a chance to get westwards. 

 Here he was told that at least a thousand sail were waiting between 

 the bay and Gibraltar, " some of them having got as far as Malaga 

 only to be swept back again. Indeed," he adds, " no vessel had 

 been able to get out into the Atlantic for three months past." 

 Supposing this current to run no faster than two knots an hour, and 



