CHAPTER XLVII

THE BAFFLING MISSISSIPPI

As inevitably as water flows down the hills of Vicksburg to the river, the visitor’s thoughts flow down always to the great spectacular, historic, mischievous, dominating stream.

Mark Twain, in that glorious book, “Life on the Mississippi,” declared, in speaking of the eternal problems of the Mississippi, that as there are not enough citizens of Louisiana to take care of all the theories about the river at the rate of one theory per individual, each citizen has two theories.  That is the case to-day as it was when Mark Twain was a pilot.  I have heard half a dozen prominent men, some of them engineers, state their views as to what should be done.  Each view seemed sound, yet all were at variance.

Consider, for example, that part of the river lying between Vicksburg and the mouth.  Here, quite aside from the problem as to the hands in which river-control work should be vested—­a very great problem in itself—­three separate and distinct physical problems are presented.

From Vicksburg to Red River Landing there are swift currents which deposit silt only at the edge of the bank, or on sand bars.  From Red River Landing to New Orleans the problem is different; here the channel is much improved, and slow currents at the sides of the river, between the natural river bank and the levee, deposit silt in the old “borrow pits”—­pits from which the earth was dug for the building of the levees—­filling them up, whereas, farther up the river, the borrow pits, instead of filling up, are likely to scour, undermining the levee.  From New Orleans to the head of the Passes—­these being the three main channels by which the river empties into the Gulf—­the banks between the natural river bed and the levees build up with silt much more rapidly than at any other point on the entire stream; here there are no sand bars, and the banks cave very little.  In this part of the river it is not current, but wind, which forms the great problem, for the winds are terrific at certain times of year, and when they blow violently against the current, waves are formed which wash out the levees.

This is the barest outline of three chief physical problems with which river engineers must contend.  There are countless others which have to be met in various ways.  In some places the water seeps through, under the levee, and bubbles up, like a spring, from the ground outside.  This, if allowed to continue, soon undermines the levee and causes a break.  The method of fighting such a seepage is interesting.  When the water begins to bubble up, a hollow tower of sand-filled sacks is built up about the place where it comes from the ground, and when this tower has raised the level of the water within it to that of the river, the pressure is of course removed, on the siphon principle.

As river-control work is at present handled, there is no centralization of authority, and friction, waste, and politics consequently play a large part.