134 
THE PHYSICAL GEOGRAPHY OP THE SEA. 
In the place where that bar was when it was one thousand 
yards nearer to New Orleans than it now is, whether it were fif- 
teen years ago or a century ago, with only fifteen or sixteen feet 
of water on it, we have now four or five times that depth. As 
new bars were successively formed seaward from the old, what 
dug up the sediment which formed the old, and lifted it up from 
where specific gravity had placed it, and carried it out to sea over 
a barrier not more than a few feet from the surface ? Indeed, Sir 
Charles himself makes this majestic stream to tear up its own bot- 
tom to depths far below the top of the bar at its mouth. He de- 
scribes the Mississippi as a river having nearly a uniform breadth 
to the distance of two thousand miles from the sea.* He makes 
it cut a bed for itself out of the soil, which is heavier than Admiral 
Smyth's deep sea water, to the depth of more than two hundred 
feetf below the top of the bar which obstructs its entrance into the 
sea. Gould not the same power which scoops out this solid mat- 
ter draw the brine up from the pool in the Mediterranean, and 
pass it out across the barrier in the Straits ? 
The traction of locomotives on rail-roads and the force of that 
traction are w^ell understood. Now have not currents in the deep 
sea power derived from some such force ? Suppose this under 
current frofti the Mediterranean to extend one hundred and sixty 
fathoms down, so as to chafe the barrier across the Straits. Upon 
the bottom of this current, then, there is a pressure of more than 
fifty atmospheres. Have we not here a source of power that 
would be capable of drawing up, by almost an insensibly slow mo- 
tion, water from almost any depth ? At any rate, it appears that 
the effect of currents by traction, or friction, or whatever force, 
does extend far below the level of their beds in shallow places. 
Were it not so — were the brine not drawn out again — it would be 
easy to prove that this indraught into the Mediterranean has taken, 
even during the period assigned by Sir Charles to the formation 
of the Delta of the Mississippi— one of the newest formations — 
salt enough to fill up the whole basin of the Mediterranean with 
* " From near its mouth at the Balize, a steam-boat may ascend for two thousand 
miles with scarcely any perceptible difference in the width of the river." — Lyell, p. 263. 
t " The Mississippi is continually shifting its course in the great alluvial plain, cut- 
ting frequently to the depth of one hundred, and even sometimes to the depth of two 
hundred and fifty feet." — Lyell, p, 273, 
