Des Arc citizen., 1859-02-18
FACTS ABOUT THE MISSISSIPPI

From Hewson's new book on leveeing,
 the Memphis Appeal condenses the fol- lowing interesting facts:
 The average fall Of the Mississippi riv- CT, for the whole distance from the Gulf of Mexico 10 the confluence of the Ohio al Cairo, during low water, IS very nearly three inches to the mile.
 During a flood, the Mississippi rises at
 Cairo fifty feet; at Friar's Point, forty two and half feet; al New Orleans, twelve feet. The average fall per mile is, then, three and half inches.
 At Cairo the Mississippi is upwards of mile wide; at New Orleans its width is but half mile. This narrowing of the down stream is accompanied by u corres- bonding rapidty and deepening.
 The observations of engineers has es- tablishea tic fact that inferior streams, running into main river, neither widen norraise it; they quicken the current and deepen the channel. The retention of flood water within the ordinary channel by levees, will have similar eifectsthe depth of the river will be increased, the velocity of the stream will be more rapid, butthere will not be, as a direct conse- quence, any elevation of tho level
 The Mississippi is shown, by the esti- mate of Sir c. Lysle, to carry earth be-
 low New Orleans to the amount, each year, of hundred and thirty-seven mil lions of cubic yards.
 As a consequence of the above, new lands is continually forming at the mouth of the Mississippi. MT. Rogers, in his report on the geology of North America, says that, as an example Of the rate at which this formation is proceeding, the old Balize, erected at the mouth of the river about l774, was, in 1881, two miles above t. There was not at that time the smallest appearance of tho island on which, forty-two years after, Uloa caused barracks to be raised for pilots, and now known as the new Balize. The rate of advance has been ninety-six feet a year. Leveeing is known, especially by the ex- ample of the Pc, to forward the rate of this advance.
 Every three inches of elevation of the water at New Orleans, represents an ele- vation at Cairo oftwelve and a halfinches.l The rate of fall, from New Orleans to the sea, is about an inch and half per mile; therefore, an advance of the mouth at "a quicker rate, in consequence of lev eeing, would give, judging by the facts in relation to the river Pc, an advance, in a hundred years, of the mouth into the Gulf |of Mexico, of four and third miles. This would cause an additional elevation of six and half inches to the flood level at New Orleans, of twenty-three inches at Friar's Point, and of twenty-seven in- ches at Cairo.
 The surface of the elevation of the bed of the river from levelling has been made a great hugbear, but when the few facts known in the case are subject to examina- lion only such planters as take very active interestin their great grand -chll- dren, will be troubled aboutthe fact, that the work of retaining the magnificent wastes of the Mississippi will cause a rise in the bed of the river of less than a third of an inch year.
 The evil arising from the extension of land at the mouth of the rivers can be neu- tralized by confining the flow of the ter minus of the stream to one outlet; by this the bars at the mouth would be secured out, and the deposit of earthly particles made further out at sea than at present, so that the Gulf stream would carry them com pletely away.
 A system of cut-of1s, by which the riv- CT would be greatly strengthened, would be highly dangerous, by causing a great acceleration of the stream; the rapid current would wash away the banks, and immense spaces of country would be re- duced by the escape of the waters, to swanps and lagoons.