552 THE POPULAR SCIENCE MONTHLY. 



the current, ami likewise exposed tbe fallacy of the declaration that 

 there is no relation between tbe quantity of sediment carried in the 

 water and the velocity of its current. 



Mr. Eads thus clearly outlined, in 1874, 1876, and 1878, one of the 

 most magnificent plans which hydraulic engineering has ever under- 

 taken. It is not simply to save thirty thousand square miles of land 

 as rich as the Delta of Egypt from devastating inundations, but to 

 extend deep water from the Gulf of Mexico to the mouth of the Ohio, 

 into the very heart of the Mississippi Valley, while permanently locat- 

 ing this magnificent channel by practically putting an end to the 

 caving of its banks. During the period we have referred to, Mr. Eads 

 delivered addresses upon this subject in the chief cities of the river, 

 published elaborate essays in w'hich it was fully explained, and de- 

 fended it against all attacks, until finally, in 1879, Congress authorized 

 the creation of a commission to consider this plan, which is known as 

 the " jetty system." The " outlet system " and the " levee system " were 

 also examined by it, and in 1880 it reported in favor of the " jetty sys- 

 tem," and recommended its adoption by Congress in its report, Feb- 

 ruary 17, 1880. ]Mr. Eads was a member of the commission for two 

 or three years. During this period, several million dollars were voted 

 by Congress to carry out the plan, which will be found described in 

 the report referred to, as agreeing substantially with the quotations 

 we have made. Two reaches of the river, Plum Point, twenty miles 

 long, and Lake Providence, thirty-five miles long, were selected for 

 improvement ; the low-water depth in the first reach was only five 

 feet, the other reach (four hundred miles below) had a depth of only 

 six feet. The permeable contraction-works, constructed of piles and 

 willows, which had been first used by Mr. Eads at the South Pass sev- 

 eral years before, were put in position for one season in the period 

 between two floods, and the effect produced by the works during 

 the first flood that followed was simply marvelous. The depth was 

 increased through the upper reach to twelve feet at low water, and 

 through the lower reach to fifteen feet, and scores of millions of 

 cubic yards of sediment were deposited between them by the checking 

 of the current by the permeable works. Thus new shore-lines of an 

 approximately uniform width were developed. In some places the 

 deposit was thirty feet deep. 



Mr. Eads was, during the time of this construction, in bad health, 

 and for some time absent from the United States. Owing to the 

 charge made by several prominent friends of the river (members of the 

 Senate and House), that the commission had abandoned the leading 

 feature of the system, the contraction-works, and had changed it to a 

 costly system of bank-revetments, and the public declarations of Mr. 

 Eads to the same effect, no further appropriations were made at the 

 last session of Congress to continue this magnificent work ; enough 

 has been done, however, to show the entire practicability of the plan. 



