198 THE PHYSICAL GEOGRAPHY OF THE SEA. 
we may now fancy that, in this exquisite system of adaptations 
and compensations, we can almost behold, in the Red and Medi- 
terranean Seas, the very waters that were held in the hollow of 
the Almighty hand when he weighed the Andes and balanced the 
hills of Africa in his comprehensive scales. 
415. In that great inland basin of Asia which holds the Caspian 
Sea, and embraces an area of one million and a half of geo- 
graphical square miles, we see the water-surface so exquisitely 
adjusted that it is just sufficient, and no more, to return to the at- 
mosphere as vapor exactly as much moisture as the atmosphere 
lends in rain to the rivers of that basin. 
416. Thus we are entitled to regard 390) the Mediterranean, 
the Red Sea, and Persian Gulf as relays, distributed along the 
route of these thirsty winds from the continents of the other hemi- 
sphere, to supply them with vapors, or to restore to them that which 
they have left behind to feed the sources of the Amazon, the Ni- 
ger, and t.he Congo. 
The hypothesis that the winds from South Africa and America 
do take the course through Europe and Asia which I have mark- 
ed out for them (Plate VII.), is supported by so many coincidences, 
to say the least, that we are entitled to regard it as probably cor- 
rect, until a train of coincidences as striking can be adduced to 
show that such is not the case. 
417. Returning once more to a consideration of the geological 
agency of the winds in accounting for the depression of the Dead 
Sea, we now see the fact most strikingly brought out before us, 
that if the Straits of Gibraltar were to be barred up, so that no 
water could pass through them, we should have a great depression 
of water-level in the Mediterranean. Three times as much water 
» is evaporated from that sea as is returned to it through the rivers. 
A portion of water evaporated from it is probably rained down and 
returned to it through the rivers ; but, supposing it to be barred 
up, as the demand upon it for vapor would exceed the supply by 
rains and rivers, it would commence to dry up. As it sinks down, 
the area exposed for evaporation would decrease, and the supplies 
to the rivers would diminish, until finally there would be estab- 
lished between the evaporation and precipitation an equilibrium, 
as in the Dead and Caspian Seas ; but, for aught we know, the 
water-level of the Mediterranean might, before this equilibrium 
