SKETCH OF JAMES B. EADS. 551 



Mr. Eads had not commenced the jetties before he turned his atten- 

 tion to the improvement of eleven hundred miles of the Mississippi 

 throughout its alluvial basin by the jetty system. On March 15, 1874, 

 in a letter to the Hon. William Windom, chairman of the Senate 

 Committee on Transportation Routes to the Seaboard, the first outline 

 of this novel plan was suggested. 



In his review of the United States Levee Commission, February 

 19, 1876, Mr. Eads said : 



" By the under-charge theory of the Delta Survey Report, caving 

 banks are attributed to the direct action of the current against them, 

 by which strata of sand underlying those of clay are supposed to be 

 washed out. This is not correct. If the water be charged with sedi- 

 ment to its normal supporting capacity, it can not take up more unless 

 the rate of current be increased. Caving banks are caused wholly by 

 the alternations in the velocity of the current. Alternations are in- 

 separable from a curved channel, because the current in the bend is 

 usually more rapid than on the point ; but, if the channel be nearly 

 uniform in width, the caving caused by the curves will be very trifling. 

 And, in proof of this, many abrupt bends exist in the lower part of 

 the river where the whole force of the current has set for years directly 

 against them without any important caving of the banks. The bend 

 at Fort St. Philip is a notable instance, the great difference in the 

 width of the flood-channel constituting the real cause of the destruc- 

 tion and caving of the banks. This tends to great irregularities in the 

 slope of the flood-line, and, consequently, great changes in current 

 velocity by which a scouring and depositing action are alternately 

 brought into very active operation. The whole of the river below the 

 Red River proves this ; caving banks are much less frequent there 

 than above, because the flood width of the river is far more uniform. 

 A correction of the high-icater channel, by reducing it to an approxi- 

 mate uniformity of width, would give uniformity to its slope and cur- 

 rent, almost entirely preventing the caving of its banks, and through 

 its present shallows, which now constitute the resting-places for its 

 snags, there would be a navigable depth, in low water, equal to that 

 which now exists in its bends. By such correction the flood-slope can 

 be permanently lowered, and in this way the entire alluvial basin, 

 from Vicksburg to Cairo, can be lifted, as it were, above all overflow, 

 and levees in that part of the river rendered useless. There can he 

 no question of this fact, and it is well for those most deeply interested 

 to jyonder it carefully before rejecting it ,' for the increased value given 

 to the territory thus reclaimed can scarcely he estimated.'''' 



Two years later, in a review of Humphreys and Abbott's " Report 

 on the Physics and Hydraulics of the Mississippi River," published in 

 Van Nostrand's " Engineering Magazine," Mr. Eads elaborated this 

 plan, and combated the declaration that the bed of the river is formed 

 of blue clay and will not erode unless very slowly under the effect of 



\ 



