On Embankments. !'J3 



2. The protection of banks against a river, to prevent its 

 overflowing and inundating large tracts of country, if judi- 

 ciously executed, is the simplest arid easiest of all sorts of 

 embankments. Few rivers of common size rise more, even 

 in the greatest floods, than five or six feet above their cus- 

 tomary level, unless they meet with some considerable inter- 

 ruption or confinement in their course, which probably can, 

 with little difficulty, be removed. In some cases, this may 

 even preclude the necessity of embanking ; but where that is 

 necessary, the embankments on both sides, ought to be 

 placed at a sufficient distance from each other, so as to con- 

 tain with ease between them, the largest contents of the 

 river, in the greatest floods. The distance and height neces- 

 sary to be attended to, in forming the banks, may easily be 

 ascertained, by measuring a section of the river, when at its 

 highest, or when the flood-mark is visible. 



When a sufficient distance is allowed between the em- 

 bankments, their perpendicular height need not exceed four 

 or six feet, but their slope should be considerable. If irre- 

 moveable obstacles are in the way, which cause the river to 

 rise higher, the banks must be made, either more distant, or 

 higher in proportion. 



The materials for making these banks should be taken, 

 as' much as possible, from the sides of the river, which will 

 have the double effect, of widening the river, and forming 

 the embankment; and there should be a trench on the in- 

 side, (from which materials may also be taken), with some 

 sluices, to discharge any water from the land side. It is pro- 

 per to add, that sluices ought likewise to be made, for ad- 

 mitting the water from the river, the advantages of which, 

 for fertilizing meadows, at certain seasons of the year, can- 

 not be doubted ( 47C ). 



When the facility, and the trifling expense at which this 

 improvement can be effected, are considered, it is matter of 

 surprise, that extensive tracts of the richest meadows, should 

 be allowed to remain in a state liable to be overflowed by 

 every flood. When these floods take place during the 

 winter, or early in spring, the water deposits a fertilizing 

 slime, which promotes vegetation, and is friendly to the 

 growth of the best kinds of natural grasses. But the floods 

 often come, when they are least of ail desired, when the 

 grass is far advanced, when the hay into which it is convert- 

 ed, is ready to be carried to the stack ( 477 ), or when the 

 crops of grain are ready to be harvested. A crop may thur 

 be destroyed, the value of which would have erected an em^ 



