The Greenville times. [volume] (Greenville, Miss.) 1868-1917, 1883-03-17


river passing out through Bayou
Atchafalaya when in flood. Now
| presume that there is not q gen
tleman on this committee whose
examination of the jetties has not
satisfied him that the depth and
width of the channel there is due
to the volume of water that goes
out through the South Pass; and
that il that volume is diminished,
the channel which is formed by
the discharge of South Pass thro'
the jetties will be diminished also.
The discharge of South Pass is
about one-tenth Of the volume of
the Mississippi river passing New
Orleans, and if that volume be di.
minished one-sixth it must follow,
| think, without any argument to
show it, that one-sixth of the vol
ume that would otherwise go throi
the South rass has been lost.
| see by a chart here prepared
recently by the Mississippi River
Commission, that the loss of food
water at Red river landing is pla-
ced at 550,OO0 cubic feet per sec
ond. That is over 10 per cent. of
the total food discharge of the
Mississippi river. | state very
emplatically in my minority report
that it is a matter Of vital import
ance, in my judgment, to close the
Atchafalaya for the benefit of nav
igation. | believe now, if it is
left alone, that the whole Missis-
sippi river will go out through it.
Such radical changes in the prin-
cipal mouths of rivers are by no
means uncommon. The Vistula is
anotable instance of it; the Adour
is another, and many other instan.
ees could be cited if my memory
served me at this moment. There
are some matters connected with
the principles which control this
question that arenecessary for the
committee to understand clearly,
in order to have proper c0mpre-
hension of the dangers that are to
be looked forward to, if the Atcha.
falaya is left unelosed.
| wish to draw the attention of
the committee to the diminution
of the size of the river bed, which
results from diminished flow of
water through 1t. In the minority
report / call attention to the two
forces which are in opposition to
each other in the flow of water in
all streams one is the force which
creates the current and which re-
suits from the fall of the water
from higher to a lower level, and
the other is the force of friction,
or the resistance which opposes
the flow of the water. This fric-
ton is unlike the friction of solids.
1t increases just in proportion to
the surface in contact with the
water which is flowing, regardless
of the weight or pressure on the
bed, and this is proven by the fact
that you cannot discharge as much
water through pipe, with a given
slope, when it is quite full, as you
can when it is nearly full.
Question. You mean that pipe
half full of water will carry more
water than a pipe full9
Answer. No, sir. | mean that
when it is nearly full it will dis
charge more than. when it is en-.
tirely full. l submit this diagram
for the purpose of proving the
fact that the friction increases III
proportion as the surface in con
tact with the water increases. The
flow of water through a partially
full pipe and through a full one
demonstrates this lpointing to the
diagraml. This curve will show
the increased flow which occurs
when portion only of the whole
frictional surface is in contact with
the water; when the water is
about 214 inches deep in a pipe q
inches in diameter it will discharge
more water than it will when it is
entirely full.
You ask me what my theory is
as to the use of levees below Red
river. | wish to submit another
diagram to show that the ratio Of
friction increases as we diminish
the size of a rivers channel
IlPointing to the second diagram.
These two circles represent the
diameter of two pipes, one a foot
! in diameter and the other foni
feet in diameter. The FRACTIONAL