THE IMPROVEMENT OF THE MISSISSIPPI RIVER. 707 



by concentration in that section about four and a half to five feet. He thinks that 

 the only way, and the quickest way, to relieve the country is to concentrate, to 

 keep the water within its banks ; and the outlet is the only plan that is possible to 

 obtain the result, the mouth of the river being stopped up; as it is certain that 

 not more than two-thirds of the water goes out now that went out of it eight years 

 ago. It would be impossible to levee the river so as to protect the banks without 

 giving the river an outlet. 



The question at issue between the advocates of the two plans is whether the 

 constriction of the channel of the river by the levees and the consequent slacking 

 and backing up of the current will have a more deleterious effect than the check- 

 ing of the rapidity of the flow below the outlets. We are not certain that the re- 

 .sult in either case is correctly stated. If in both, the deposition of sediment would 

 be similar in each case. If, however, as the engineers claim, the velocity of 

 the current is increased by confining the water within its banks, the danger of its 

 cutting the banks and levees during freshets will be largely increased, while on the 

 other hand if the current below the outlet is liable to become in any degree less 

 swift, it need only be so during high water, when great velocity is objectionable 

 rather than otherwise; for if we understand the Cowdon idea it is simply to make 

 use of this outlet in times of freshets and floods, as a safety-valve, so to speak. 



The Atchafalaya River, or Bayou, has been found of immense advantage in 

 relieving both the Red River and Mississippi in times of floods, and at this very 

 time Senator Kellogg is asking a large appropriation for deepening it. The Com- 

 mission, in speaking of the non-conformity of the Atchafalaya to their theory, say, 

 "That the Atchafalaya remained so long unaltered, and is now evidently enlarg- 

 ing, is owing to important changes in the bed of the Mississippi near it, by which 

 a large portion of the floods of the Red River have recently been discharged 

 through it." The Commission made no recommendation regarding the Atchafal- 

 aya outlet except such work as is necessary to prevent its enlargement. Captain 

 Suter, one of the Commission, has recently expressed himself favorable to a plan 

 |v^hich will cut off the floods from tributary streams. 



So far as we can see, this is precisely what the Cowdon plan proposes, viz : 

 to create an outlet which will let off surplus water and of course control it to pre- 

 ven.t detriment either to the country adjacent to and at the mouth of the outlet, 

 or in the channel of the river below it. If a lock can be established and 

 worked at Plaquimine, why cannot adequate engineering devices be conscructed 

 to control the outflow at the Lake Borgne outlet? If works can be put in to 

 prevent the enlargement of the Atchafalaya, why not along the course of the 

 Lake Borgne outlet. 



As to the "sub-delta" bugaboo, it is an old cry. The same engineers who 

 oppose the outlet plan opposed the jetty plan, and on the same or similar grounds. 

 A " sub-delta " would form at the extremity of the jetties and would continue to 

 form there, no matter how far they were extended, but such has not proved to 

 be the result. The whole question is confined to the possibility and feasibility of 

 letting off the surplus water and retaining the amount necessary for navigation 



