Burlington hawk-eye. [volume] (Burlington, Iowa) 1845-185?, 1849-03-29
The Are Of fhe Mi.sissinnis

Inc age OF the Mlss1Ss1pp1.
We find in one Of our eastern exchang.
es, the following extract fron paper read
before the American Association for the
Promotion Of Science at Philadelphia, BY
Professor DICKINSON, on the age Of the
Mississippi river. It embraces details
and statistics which are new 10 US, and
will, we doubt not, be new also 10 our
readers. Professor d. says:
We will now give you the quantity Of
solid matter with which the waters Of The
Mississippi are annually charged, togeth-
er with its effects III the formation Of lands
Or the filling up Of depressions. In order
TO arrive at these required facts, the fol.
lowing methods were adopted: first, sel
ries Of glass vessels Of cylindrical form
was procured, at one end Of which was
attached a tin tube Of the same cylindrical
diameter as that Of the glass vessel TO
which it was attached in the tin tube inn
mediately above its junction with the glass
cylinder there was inserted small glass
cock, by which the tin tube could be con:
veniently discharged Of its contents at
pleasure, without causing any disturbance
to the contents Of the glass vessel below
this tin tube was in length 48 inches
The tube was charged with water from
the Mississippi river, and this water was
allowed time to deposit its contents into
the glass vessel below that being accom-
plished, the water was drawn of, and the
tube te-charged by water from the river;
each particular charge being noted. This
was successively repeated fromrhe differ
eht conditions and stages Of the rivers
height and velocity, which very material
ly affects the quantity of suspension, and
BY succession Of such chargings and dis
chargings Of the tintube, amounting in all
to l4S times, or in the aggregate to col
umn Of water of 1886 feet, from which
column ofwater there was deposited coll
umn Of sediment, inclosed in three tubes,
Of a. inches. Assuming that, therefore,
to be the true quantity and the true pros
duct Of a column Of river water "a, 232
inches, i necessarily follows that as 45is
to 1929, SO is the quantity Of sediment
airy matter contained in the water to the
volume Of the river, or, in other figures
and words, the mean proportional quanti-
" Of sediment, to the river is as to 528.
We have already ascertained the quantity
Of water annually discharged BY the Mis-
sissippi River to be 1883, 900, 636, $50
cubic feet; there must, then be deposited
from that quantity Of water %, l88. O53,-
S92 10 cubic feet Of solid matter. There
can be no question but that much matter in
the character Of coarse sand and gravel is
transported by the river current. Of the
quantity Of this your committee could have
hopossible opportunity Of estimating the
volume.
- Being possession ofthe data by which
may be computed, with some approxima-
ton TO certainty, the effects Of the Mis.is-
sippi deposits in The formation Of land, or
in filling up the gulf, into which it is
emptied, we will avail ourselves Of such
data, and endeavor 10 present the quaint.
ties deducible therefrom. In estimating
the delta Of the Mississippi we have adopt
ed for it the superfces assumed by Dr.
Lyell in his Investigation Of this subject,
and will say, with that gentleman, that the
delta of the Mississippi river comprehends
all that great alluvial plain which lies be-
low or to the south of what is or recently.
was the first branching out or highest arm
OF the river called the Atchafalaya. This
delta is computed to contain superficial
area Of 1860 square miles. In deciding
on the depth Of this quantity, we will adopt
that which was assumed by Prof. Kiddel
on this subject, and say that it is Of the
average depth Of one-fifth Of a mile, or
! 1850 feet-inferred from that being the
average depth Of the Gulf Of Mexico from
the Balize to the Gulf Of Florida. We
find BY computation agreeably to the above
data, that it would require quantity not
less than 400, 1878, 429, 44O, 900 cubic feet,
or 1920 miles for solid matter, to consti-
tute this delta, having ascertained the
quantity Of solid matter annually brought
down by The Mississippi river TO be 49,
l88, O53,8 1892 cubic feet, which would be
equal TO one square mile Of the depth Of
1866 feet in 38l is days, or one cubic
mile in five years and eighty-one days
1t, therefore, follows that il would require
a series of l4,303 As years for the river
10 effect the formation Of the present delta.
"Have you got letter for my boss ?"
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