34 



FARMERS' REGISTER. 



[No. 1 



that celerity depends less upon the declivity of the 

 channel than upon the weifjht of water. The 

 importance ot" this ohjectiou is confirmed hy this 

 remarkable fact, tliat when once a river acqiiires a 

 great celerity, it will bolh preserve it while run- 

 ning through a level country, and even surmount 

 heights without spreading much to a side, or, at 

 least, without producing any inundation of any 

 moment.* 3. That by diminishing the celerity of 

 the river, it woahl be ni'^re liable lo be warped and 

 impeded, as a greater quantity of sulliagei would 

 thus be deposited in the channel. 



At the same time, a caution must be given 

 against carrying the principle here laid down to an 

 extreme. It is as ineffectual to confine a river 

 within too narrow boimds, as it is to give it loo 

 lari^e an expanse. The, width of the channel, 

 therefore, should be such as will admit the water 

 to flow freely, and maintain a proper or safo velo- 

 city. 



To deepen the channel of a river, all the means 

 which have been recommended lor defending 

 banks from encroachments — the removal of ob- 

 Btructions, and the erection of bulwarks to prevent 

 the stream fi"om spreadintr — will be lound extreme- 

 ly conducive. In some instances, these operations 

 may even preclude the necessity of embiuikini)-. 



Where rivers flow through a very flat country, 

 and their current is consequently less rapid, their 

 overflowing, instead of being destructive, often 

 produces beneficial effects, by depositiniz; mud and 

 other rich sediment, which tends to fertilize the soil 

 in a very high degree. Where this is the case, 

 embankment has a double advantage; (or by means 

 of sluices, a portion of the water can bp adn)iltcd 

 at the upper side, and retained at pleasure, iiv 

 which means the influence of its effects can be 



* Buffon on rivers. 



t Shmy, sandy ,^or other earthy deposit. 



regulated as circumstances' require. Those large 

 rivers that flow through valleys of wide expanse, 

 have always a lengthened and crooked course, oc- 

 casioned by the frequent chances thai lake plac-e, 

 by floods acting against ihe soil of which the Kjvv 

 ground is composed. To make new and straiLfht 

 channels for such rivers, would be the most eflec- 

 tual improvement; but this, in many cases, would 

 be attended with an expense much oreater than 

 the advantages to be gaiueil. In others, however, 

 it would be advisable to straighten such parts as 

 are very crooked, and where the length of cutting 

 would be short, ami the expense moderate. By 

 this means, the length of embiud<rnent would be 

 shortened, and kept in a straiirht line, which is a 

 great desideratum. Indeed, the line of embank- 

 ment should be kept as straight as possible, even 

 if the Course of the liver be crooked; for it is 

 i'liXainst the bends and turns that the waier has 

 greatest weight, and is most apt to fiurst through 

 the bank. The loss of this ground, by its being 

 excluded from culture, is counlerbalanced by the 

 security which it provides, in fjiving the water 

 more room, at<d consequently lessenina its force 

 and pressure; and though not accessible to the 

 plough, is valuable as meadow or pasture. Tlie 

 annexed plan, No. lil. will tijrllier explain these 

 positions. 



In all smaller streams, or burns* (as they are 

 called in Srotland). straighteninir, widenin<>-, and 

 deepening the channel, is llie first and greatest 

 improvement; and, in many cases, these opera- 

 lions alone may be sufficient lo confine the whole 

 body of water in a flood, and so render anv eui- 

 bankment or furtlier defence unnecessary. If the 

 capacity of the channel is not suflii-iently enlargi-d 

 by these means, the wilth between the embank- 

 ments will require to be the greater, and their 



* Brooks, in England. 



Plate III. Plan and Section representing a New Channel and Eiubankment for a River. 

 The Points at^A should bt- guarded by a facing' of Stones or by Piles of AVood. 



The embankments for the new cut is represented by the straight double rows of dotted lines, and 

 should be 10 feet distant from the edge of the cut. The dimensions of the new cut should be 

 30 feet wide at top; 10 feet at bottom, and 6 feet deep, or in these proportions, according to 

 the size of the stream. 



Section. — A, Slope faced with turf B, Sown with grass. C, Scarcement three feet broad. 

 D, Pahng. Trees must be removed by the roots. 



