76 THE IMPROVEMENT OF RIVERS. 



by the State, conflicting interests, lack of knowledge, and a variety of causes conspired 

 to render the work expensive and not always of the greatest benefit. Then came the 

 Civil War with its devastation and derangement of conditions, and the levees were 

 virtually abandoned or wholly destroyed. Attempts were made by the local govern- 

 ments later on to repair them and even to build new ones, with varying success, until 

 finally, about 1880, the Federal Government took the matter in hand. The State 

 governments of Missouri, Arkansas, Mississippi, and Louisiana, however, continued 

 their works in certain localities in cooperation with the United States, since which 

 time marked improvements have been made in the design and methods of construction. 



Reports show that more than $15,000,000 have been expended on levees by the 

 United States. 



Location. Permanence, economy of construction and of maintenance, and future 

 enlargement are involved in the location of a system of levees, but it is a rare thing to 

 see a location made with these objects solely in View. Too often the interests of the local 

 property holders are the first consideration. While these should be recognized to a certain 

 extent, the general benefits to be derived from properly located lines should always 

 be considered first. As the systems are extended and completed the flood-plane will 

 rise, necessitating new work which, if carried on with locations improperly made, will 

 mean the expenditure of vast sums of money. It is far better to expend that money 

 in first constructions so located as to give the best protection to the greatest number, 

 even if such protection damages the few. In the original alignment of the levee systems 

 along the Mississippi no attention was given to the laws of motion of fluids; levees 

 wound around every cow-pen and horse-lot, presenting obtuse angles at critical places 

 without additional thickness of section. These locations have still been adhered to 

 in many cases in the enlargements made by the General Government ; in many other 

 cases the embankments have long since gone into the river with caving-banks or have 

 been weakened at their salient angles and destroyed by the floods. 



Angles should always be avoided and curves substituted flat enough to admit of 

 a railroad track being operated. Hewson* lays down the following rules for locating 

 a levee: "The first duty is the mapping out carefully of the bank, and, as far as may 

 be done by a careful sketching, of the current set, the 'caving,' and the 'making.' In 

 the case of cavings and makings, every information as to their commencement, their 

 rate of progress inwards, and their advance down stream should be obtained carefully 

 from local information and recorded at the proj^r prints on the map. The cavings 

 and the makings of the bank pass down stream in a series of waves, period after period ; 

 and therefore by ascertaining the rate of descent, the rate of penetration of a 'cave,' 

 or the extension of a 'make,' at the point of its operation, the location of the levee 

 opposite that point may be made with a full knowledge of the conditions of its perma- 

 nence." The following notes from the "Manual" of the Dutch engineer Storm- 

 Buy sing may also be quoted: "The trace of the new dike should of course have regard 



* Embanking Lands from River Floods. 



