ns 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 a 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,