COG 



SCIENCE. 



[N. S. Vol. XIX. No. 485. 



things than any other outlet scheme. The 

 path of the subsidiary channel would lie 

 wholly within the alluvial basin and over 

 ground undoubtedly occupied in many 

 changing locations by the stream, or parts 

 of it, in bygone ages. It would be like 

 what the river does, now on a small scale. 

 in many places. At every 'chute' there is 

 an outlet from the main stream and a sub- 

 sidiary channel passing around an island 

 and joining the main stream below. It 

 may be one mile long or twenty-five. The 

 island may be a mere 'towhead,' or it may 

 be large enough to form a county. My 

 subsidiary channels down the St. Francis 

 and Yazoo basins would be only longer 

 chutes. 



Another scheme has been proposed, how- 

 ever, which I regard as more impracticable, 

 if possible, than the one which I have de- 

 scribed. It is to take an outlet channel 

 across the upper end of the St. Francis 

 basin through Crawley's ridge and thence 

 to the gulf on a line lying wholly west of 

 the Mississippi River. I have indicated 

 one of its suggested locations by the broken 

 red line on the map connecting the points 

 at which it would leave and rejoin the sub- 

 sidiary channel indicated by the continuous 

 red line. 



The first point to be noticed about such 

 a plan is that it would cut off all the west- 

 ern confluents of the main stream below 

 Cairo— the upper St. Francis, White, Ar- 

 kansas, Black and Red. It would be an 

 intercepting sewer for the southwestern 

 quarter of the Mississippi valley. It would 

 be a great big river. It would require an 

 amount of excavation equal to several Pan- 

 ama canals, and levees nearly as great as 

 those on the main river, in order to enable 

 it to hold its own floods. Men have done 

 a great deal in the way of improving the 

 work of the Almighty in the creation of 

 the earth already, but this would be a more 



extensive program of reconstruction than 

 any before attempted. 



The next point to be noted is that it 

 would permanently lessen the volume of 

 the main stream from the location of the 

 outlet to the gulf. It would do this to the 

 extent of the discharge of the intercepted 

 tributaries plus the volume taken from the 

 channel by the outlet. What that volume 

 would be would depend upon whether the 

 scheme contemplated a mere tapping 

 process, to take off the upper few feet of 

 extreme floods, leaving the levees to take 

 care of all ordinary floods, or such large 

 reduction of volume as would make the 

 levees unnecessary. If the former, then, 

 as I have already pointed out, we should 

 still have 1,400 miles of levee to maintain 

 at nearly the same cost and hazard which 

 they impose upon us now, besides a second 

 river to take care of, with all its vicious 

 tendencies and caprices; if the latter, we 

 would have two Mississippi rivers to be 

 maintained in equilibriiun against the 

 forces of nature which tend constantly in 

 such a situation to give to that channel 

 which hath, and take away from that chan- 

 nel which hath not, even that which it hath. 



Such schemes necessarily take a man far 

 afield in the domain of speculation, but this 

 much is certain; if it should prove to be 

 impossible to divert enough water from the 

 main stream in that way to prevent the 

 overflow of the natural bank, the project 

 would have failed as a means of protecting 

 the alluvial lands from inundation ; and, on 

 the other hand, if such diversion should be 

 found possible and be accomplished the de- 

 pleted main stream would contract its 

 channel to correspond with its lessened dis- 

 charge. A river channel through an 

 erosible formation always fits the river as 

 a turtle's shell fits its back. There is no 

 reason why the channel of the Lower Mis- 

 sissippi is larger than the channel of the 



