38 
THE OCEAN WORLD. 
that the quantity of salt water supplied hy the upper current through 
the Straits of Gibraltar is equal to seventy-two cubic miles per aunum, 
while the quantity of fresh water brought down by the rivers is equal 
to sis, and the quantity lost hy evaporation to twelve cubic miles per 
annum. This would leave an annual excess of sixty-sis 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 Phoenix, 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 neighbour- 
hood of Tangier, more than twelve miles from the spot where she had 
disappeared under the waves. She had therefore traversed that distance, 
drawn hy the action of the under current in a direction opposite to that 
of the surface current. This ascertained fact, added to some recent 
experiments, lend their 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 Almeria 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 assuming its depth to be 
four hundred feet only, and its width seven miles, and that it contained 
the average proportion of solid matter, estimated at one-thirtieth, it 
appears that salt enough to make eighty-eight cubic miles of solid 
matter were carried into the Mediterranean in those ninety day?' 
“ Now,” continues Dr. Maury, “ unless there were some escape for all 
this solid matter which has been running into the sea, not for ninety 
days, but for ages, it is very clear that the Mediterranean would long 
ere this have been a vat of strong brine, or a bed of cubic crystals.” 
For the same reason, Dr. Maury considers it certain that there is sfi 
