The Cairo bulletin. [volume] (Cairo, Ill.) 1872-1878, 1876-02-23
SURVEY OF THE MISSISSIPPI RIVER ~ rnR
VICINITY or CAIRO.


Secretary OF War.
| SURVEY OF THE MISSISSIPPI RIVER IN TuR
| VICINITY or CAIRO.
| ENGINEER OFFICE. L. 4. A.,
ST. LOUIS, Mo-, Feb. 8, 1876.
| GENERAL: I have the honor to for
ward herewith tracing Of compare
tive map OF the Mississippi river In the
| vicinity of Cairo, showing the changes
during the interval between July, 1874,
and November, 1875.
The shore.lines in black are those
given by the survey made In November,
1875; those shown in yellow are from
careful typographical sketches made at
| the time the triangulation was made in
July, 1874. The rapid erosion OF the
Illinois shore opposite Eliza Towhead
has caused great alarm to the citizens OF
Cairo, and fear that the Mississippi may
| continue to work its way toward juno.
ton with the Ohio above the city, and
leave the city on an island, both sides of
which will be exposed to the action of
the currents or, II not, that the bend
will approach the Ohio at lower point,
and in that case cndangcr the
site Of the city. They. consequently, "a
| have been informed, propose to apply
to congress Tor an appropriation for the
protection of tue caving bank from near
the foot of Dickcy's Island to the spur
| bikes opposite the town. In anticipation
of such application the survey of Noyem-
Der, 1875, was made in order that the
necessary information might be in readi-
ness when required to enable congress to
pass upon the prOpricty of affcrding the
relief asked for.
In order to fairly represent the approx
imation of the Mississippi toward juno
ton with the Ohio above the city, the
shore-lincs OF the Ohio river have been
carefully transferred from map pub
lished in the coast survey report tor 1854,
| (which Is the best authority In posses
sion OF this office aud which is prcsum-
ed to be substantially correct. as the
banks Of the Ohio are judged to be stable,
and have changed but slightly, it at all
since the date OF the survey used as au-
thority.
The minimum distance between the
two rivers il thus shown TO be nearly
1900 feet now, whereas 1t was. In July,
1874, 4,l75 feet, q decrease OF l75 feet dur.
ing the interval OF fifteen months. The
point Of least distance between the rivers
does not coincide with the locality where
the greatest erosion has occurred. Accord
ing to the usual tendency of physical
changes to progress down stream, Ii Is
reasonable to expect that the locality of
greatest erosion the coming sea-
lon will more nearly coincide with the
point of least distance between the two
rivers. Should this be the case, with
| the rate OF maximum erosion in the past
as an index to the future. the distance be-
tween the two rivers Is likely to be re-
duced the coming season to about $500
feet. BY scale measurement OH the
i A( n
lance between the two rivers was
then 4,SSS feet, and map made
In the office Of the Cairo and st.
Louis railroad, makes the same distance
1, 800 feet the latter map was made after
| the location OF the railroad, which was
made in the autumn Of 1871, by Mrs.. +.
McGregOry, who Is now an assistant IN
this office, and bears testimony that at
that time the current did not set against
the bank of the river; statement which
must be correct, as the road was finally
built quite close to the river bank, which
certainly would not have been done II the
bank had been caving ct that time. These
facts confirm the older maps in their testi-
mony that the changes were slight be-
tween 1854 and 1871. The waste between
1871 land probablya considerably later
date and July 1874 must have been about
| ltct. luc CthukcS uuIIuS tue lust lew
years have therefore been rapid, and by
applying the rate 1t would be easy to cal
clllate the comparatively short period re-
quircd to establish the junction Of the
two rivers above the city.
All such calculations are deceptive, as
eroslons In any particular locality or in
any particular direction are known to in
crease TO maximum. then decrease to
practical zero.
The apex OF the bend will move down
stream, and the point OF maximum crO-
sion travels with It. / therefor incline to
the opinion that the apprehension Of the
junction OF the rivers above the
city Is uniosndcd, as also that
as to the present TOWNSHIP being cndan-
gered at any date within provisions now. .
AZ the same time there can be no ques-
ton but that large part OF the vacant
ground In. the rear Of the town Will be
cut away in the carly future, unless the
river changes the course of It's strongest
current. which there is no apparent rca.
son to expect.
sAt the lower end of the bend, as IL now
exists, series Of spur.dikcs are found
when were built by the Cairo Land
company IN the period between 1868
anu 1902, 70 check then threat