CURRENTS OF THE OCEAN. 31 
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 upper 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 Phenix, 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 
