It is this inward current, he thinks, that produces the deposit, and in
doing so carries with it no small degree of sea drift. The influx of the
lower column flowing up stream, after it passes the dead point, is
allowed time and opportunity for the sediment to deposit. The principle
of the reflex current is somewhat that of an eddy, not only produced by
the conflict of two opposing bodies of water, but also is much
influenced in the under currents by the multitude of estuaries presented
by the irregular sea front of the coast.
A gentleman, who seems to have taken a very statistical view of these
bars, makes the following business-like and curious calculation as to
their immensity: we introduce it on account of its originality. He says
the average quantity of water discharged per second is five hundred and
ten thousand cubic feet. The quantity of salt suspended, one in three
thousand by volume. The quantity of mud discharged, one hundred and
seventy cubic feet per second. Considering seventeen cubic feet equal to
one ton, the daily discharge of mud is eight hundred and sixty-four
thousand tons, and would require a fleet of seventeen hundred and
twenty-eight ships, of five hundred tons each, to transport the average
daily discharge. And to lift this immense quantity of matter, it would
require about seven hundred and seventy-one dredging machines, sixteen
horse power, with a capacity of labor amounting to one hundred and forty
tons, working eight hours.
Another class of sedimentary formations met with along the banks of the
Mississippi are the battures. There is one remarkable instance of these
in front of New Orleans, which has led to much private dispute, and even
public disturbance, as to ownership. Within sixty years, in front of the
Second Municipality of the city, the amount of alluvial formations
susceptible of private ownership were worth over five millions of
dollars, that is, nearly one hundred thousand dollars per annum, and the
causes which have produced them are still at work, and will probably
remain so. As far back as 1847 these remarks were made upon the subject:
'The value of the annual alluvial deposits in front of the Second
Municipality now is not less than two hundred thousand dollars, and,
with the exception of the batture between the Faubourg St. Mary line and
Lacourse street, all belongs to this municipality.' 'Such a source of
wealth was never possessed by any city before. In truth, it may be said
that nature is our taxgatherer, levying by her immutable laws tribute
from the banks of rivers and from the summits of mountains thousands of
miles distant to enrich, improve, and adorn our favored city.' There are
numerous other examples of the kind going on elsewhere along the river.
But the greatest exhibition of the wonderful character of the
Mississippi, and in which all its singular effects are most distinctly
shown, is in its Delta. For a long succession of years the immense
quantities of sediment, of which we have already spoken, had gradually
precipitated upon this portion of the river until it reached the
surface. Drift now lodged upon it: the decomposition of drift and the
accumulation of other vegetable matter soon furnished a suitable bed for
the growth of a marine vegetation, and now a vast area, a level expanse
of waste land and marsh, is seen extending a great distance into the
Gulf, ramified here and there by the outlets of the river. Indeed, so
rapid have been these formations, that upon the testimony of history,
the Mississippi River to-day is twenty-nine miles farther in the Gulf
than it was in 1754.
Mr. Forshey, an engineer, remarks that 'the superficial area of the true
Delta formation of the Mississippi, or below Baton Rouge, where the last
bluffs are found, is about fifteen thousand square miles, constituting a
region of mean width seventy-five miles, and mean length two hundred
miles. Probable depth of alluvion is about one fifth of a mile, by
inference from the depth of the Gulf of Mexico.' In the vicinity of New
Orleans, boring to a depth of two hundred feet, fossils, such as shells,
bones, etc., have been found. And at thirty feet specimens of pottery
and other evidences of Indian habitation have been discovered. The
foundation upon which rest the alluvial formations has been found to
consist of a hard blue silicious clay, closely resembling that met with
in the bed of the Mississippi. The most recent of the alluvial fields of
the Delta have been constituted a parish, termed Plaquemine. In 1800,
according to one authority, there were but very few acres in cultivation
in the entire parish. Since leveeing above, the deposit has been
extremely rapid, until now we find some excellent plantations in
Plaquemine. Fifty miles below New Orleans the tillable land is nearly a
mile in width; below there, it becomes gradually less, until it is lost
in the Gulf. Still the accumulations are going on, and it is impossible
even to surmise what changes the great river may yet effect in the
future geography of this section of the American continent.
Considering the multitude of streams and vastness of area drained by the
Mississippi, it is natural to suppose the river is much affected in the
stage of its water by the seasons. We have seen that the meltings of the
Rocky Mountain snows, the mountain rills of the Alleghanies, the waters
of the valleys of the upper river, of the Missouri, of the Ohio, the
Arkansas, the Yazoo, and the Red, all find outlet through this one
stream. There are certain seasons in the year when all these widely
distant localities are subject to a gradual approach of warmth from the
south, until they arrive at a sort of climatic average. This creates a
maximum of the supply of water. The inverse then takes place, and a
minimum results. For instance, in the latter part of December, the lower
latitudes of the Mississippi begin to experience their annual rains.
These by degrees tend northward as the season advances. In March
commence the thaws of the southern borders of the zone of snow and ice;
and during April, May, and June, it reaches to the most distant
tributary fountain head. The river now is at its highest. The reverse
then sets in. All the tributaries have their excess, the heats of summer
are at hand, drought and evaporation soon exhaust the surplus of the
streams, and the river is at its lowest.
To meet the great annual excess of water in the Mississippi, nature has
provided sure safeguards. These are termed bayous, and are found
everywhere along the river, below the mouth of the Ohio. Additional
preventives against inundation are the lagoons, or sea-water lakes, of
the coast. Into these bayous and lagoons, as the river becomes high, the
excess of water backs or flows. They are natural reservoirs, to ease the
rise, and prevent the inevitable suddenness and danger which would
result without them. In these reservoirs the water rises or falls with
the river; and when the fall becomes permanent, the water in the
bayous--the lagoons having outlet into the sea--falls with it, returning
into the main stream, and finding entrance into the Gulf, from which it
had been temporarily detained. Without the bayous the lands adjacent to
the Lower Mississippi would, with very few exceptions, be subject to an
annual overflow, and be perfectly worthless for certain agricultural
purposes. In summer the bayous in numerous instances become perfectly
dry, and give a very singular effect to the appearance of the country.
Below the mouth of the Red River the tributaries of the Mississippi
cease, and the entire volume of the river is attained. As a protection
against serious consequences arising out of such an immense mass of
water, nature has again introduced a remedy. This consists in a number
of lateral branches, which leave the river a short distance below the
mouth of the Red, tending directly to the Gulf, through a continuous
chain of conduits, lakes, and marshes.
The principal bayous, which exert so important a part in regulating the
stage of this part of the river, are in length and distance from the
Gulf as follows:
_Distance By River._
_Miles._ _Miles._
Bayou La Fourche, from the Mississippi River to the Gulf, 100 180
" Plaquemine, " " " 60 210
" Manchac, " " " 50 220
" Atchafalaya, " " " 110 300
The course of the bayous, it will be seen, have a more direct route than
the river. Their average width is one thousand feet, and fall twenty-two
feet. Their average velocity is about three and two tenths miles per
hour. Though the rise of the river at Baton Rouge sometimes attains a
height of thirty feet, so great is the relieving capacity of these
lateral branches, that at New Orleans the rise never exceeds twelve
feet. At Point à la Hache the difference between the highest and lowest
stage is but six feet; at Fort Jackson, four feet, while it falls to low
water mark when it enters the sea.
Having briefly noted the peculiarities of the Mississippi, a few facts
in recapitulation may place it in a more comprehensive attitude as
regards its appearance and size. In the north, after leaving the Falls
of St. Anthony, the river has but the characteristics of a single
stream, but below the Ohio we find it combines the peculiarities of a
number. The water here begins to show signs of almost a new nature and
greater density. The river develops into a much wider channel, and its
peculiarities become more marked and impressive.
Strange as it may seem, the greatest mean width of the Lower Mississippi
is at the confluence of the Ohio, and from this point it gradually
becomes narrower, until it is but little more than half that width as it
draws near the Gulf. This gives the river a kind of funnel shape, and if
it were not for the numerous bayous and lateral branches, which we have
explained, the most violent convulsion and devastation would arise. In
the United States Engineer Reports we find this statement:
The mean width of the Mississippi
River between the Ohio _Feet._
and Arkansas Rivers, 4,500
Mean width between the Arkansas
and Red Rivers, 4,100
Mean width between the Red
River and Donaldsonville, 3,000
Mean width between Donaldsonville
and the Gulf, 2,500
Above the Red River the range between high and low water is about
forty-five feet, and thence to the Gulf it gradually diminishes to zero.
The greatest velocity of current is about five and a half miles per hour
during floods, and about one and a half miles per hour during low water.
The river is above mean height from January to July, and below from
August to December. The greatest height is attained from March to June,
and the lowest from October to November.
The mud of the Mississippi is very yielding, insomuch that an allowance
of several feet is often made where the draught of a vessel exceeds the
clear depth of the water. We have heard of cases where steamers have
ploughed successfully through four feet of it.
It is singular, too, and exhibits still more clearly what we have said
of deposits, that the lower river for the most part runs along the
summit of a ridge of its own formation, and annually this ridge is
becoming more elevated. The inland deposits are made by the bayous and
their overflow. The lands close to the river are disproportionately
higher than those farther back. The average distance from the river to
the swamp is about two and a half miles. And the slope in some places
sinks to a depression of eighteen feet to a mile. It is upon this strip
of tillable earth that the river plantations are located. By a system of
drainage even much of the swamp lands now unconverted might soon be
turned to profitable use.
The numerous islands and old channels of the Mississippi are also
another source of wonder to the traveller. The 'cut offs,' previously
explained, are mainly the cause of both. In the first instance, the
river forces its way by a new route, and joins the river below; this
necessarily detaches a certain amount of land from the main shore. As
for the second, after the river has taken this new route, its main
abrasive action follows with it. The water in the old channel becomes
comparatively quiet, sediment is rapidly deposited, and in course of
time the old bed loses its identity, or becomes a beautiful lake,
numerous instances of which occur between the Ohio and the Red Rivers.
As the Mississippi reaches the neighborhood of the Balize the east banks
slope to the sea level very rapidly, running off toward the end at a
declination of three feet to a mile; after which, the land is soon lost
in wet sea marsh, covered by tides. On the west side the land declines
more slowly, and in some places is deeply wooded. The chenières begin
where the declination ends, and the great reservoirs of the coast, the
lakes and lagoons, begin.
The incessant changes in the channel and filling up of the Mississippi
preclude the possibility of a table of distances mathematically
accurate, yet we have taken from accepted authorities the number of
miles from the Gulf to the principal points along its banks. The table
may be of service to the many that are daily tending to the great Father
of Rivers, and those at home may be able to form, perhaps, a better
estimate of the immense length of the stream, by having before them
these figures:
TABLE _of Distances and Altitudes on the Mississippi_.
_Above level_
From the Gulf of Mexico _Miles. of the sea_.
To New Orleans, La., 110 10.5
" Donaldsonville, La., 188 ....
" Plaquemine, La., 210 ....
" Baton Rouge, La., 240 ....
" Port Hudson, La., 263 ....
" Bayou Sara, La., 275 ....
" Mouth of the Red River, La., 315 76
" Fort Adams, Miss., 327 ....
" Natchez, Miss., 387 86
" Grand Gulf, Miss., 450 ....
" Warrenton, Miss., 500 ....
" Vicksburg, Miss., 512 ....
" Mouth of the Yazoo River, Miss., 522 ....
" Milliken's Bend, La., 538 ....
" Lake Providence, La., 588 ....
" Greenville, Miss., 657 ....
" Napoleon, Ark., and mouth of the Arkansas River, 730 ....
" Mouth of White River, Ark., 756 ....
" Helena, Ark., 838 ....
" Mouth of St. Francis River, Ark., 848 ....
" Memphis, Tenn., 928 ....
" New Madrid, Mo., 1,113 ....
" Columbus, Ky., 1,167 ....
" Cairo, Ill., and mouth of Ohio River, 1,187 324
" Cape Girardeau, Mo., 1,237 ....
" St. Louis, Mo., 1,388 382
" Mouth of the Illinois River, 1,422 ....
" Upper Iowa River, Io., 1,984 ....
" Mouth of St. Peter's River, Minn., 2,198 744
" Falls of St. Anthony, Minn., 2,206 856
" Lake Cass, Minn., 2,761 1,402
" Itasca Lake, Minn., 2,890 1,575
" Springs on the summit of Hauteurs de Terre, 2,896 1,680
The Lower Mississippi presents another feature that should not be
forgotten, and which sets forth a great design. Immense forests of
cottonwood and ash are to be seen growing along its banks. These trees
are of rapid growth, and afford excellent (in fact the best, with the
exception of coal) fuel for steamers. Indeed, they constitute much the
greater portion of wood consumed in river navigation. So suitable is the
rich alluvion of the river banks to the growth of these trees, that in
ten years they attain to a sufficient size for felling. Plantations
lying uncultivated for a single year, in the second present a handsome
young growth of cottonwood. This fact is now very well proven on the
Mississippi; the war has ruined agricultural labor almost entirely. No
apprehensions are ever felt by steamboat men on the subject of fuel; the
supply is inexhaustible and reproducing.
The other woods found upon the river, but not, let it be said, to the
extent of the cottonwood or the ash, are the live and water oak, swamp
dogwood, willow, myrtle, wild pecan, elm, and ash. The cypress tree is
found in extensive forests back from the river in the swamps. This tree
attains an enormous height, and is without branches until attaining the
very top, and then they are short and crooked, presenting a very fine
and sparse foliage. The wood of the cypress is very little used upon the
river, not, perhaps, in consequence of its inferiority of quality, but
the difficulty of access to it.
In conclusion, we cannot withhold a few words upon the singular typical
similarity between the appearance of vegetation upon its banks and the
river itself. Gray forests of cypress, the blended foliage of the oak,
the cottonwood, and the ash, with a charming intermixture of that
beautiful parasitic evergreen, the mistletoe, above Vicksburg, suggest
the blooming grandeur of the stream. Below, the appearance of a new
parasite, the Spanish moss, draping the trees with a cold, hoary-looking
vegetation, casts a melancholy and matured dignity upon the scene. Like
the gray locks of age, it reminds the passer by of centuries gone, when
the red savage in his canoe toiled upon its turbid flood; it recalls the
day of discovery, when De Soto and La Salle sought its mighty torrent in
search of gain, and found death; and now looms before us the noblest
picture of all, the existence of a maturing civilization upon its banks.
Associated thus with an ever-present suggestion of a remarkable and
ever-forming antiquity, the Mississippi becomes indeed the wonder of
waters. Ponce de Leon, that most romantic of early Spanish explorers,
traversed the continent in search of a 'fountain of everlasting youth;'
the powerful republic of the West, has _found_ in the 'Father of Waters'
a fountain and a stream of everlasting, vigorous life, wealth, and
convenience.