On the Drainage of Land. 



283 



it may be laid on and taken off at pleasure, and discreetly used 

 by a skilful husbandman, invigorates and sweetens it, while stag- 

 nant water fills the sward with grasses of the coarsest character. 

 It is indeed thought by many intelligent graziers to engender an 

 insect which spreads itself over marshy ground, and, being there 

 eaten by sheep along with the grass, is supposed to occasion the 

 rot. Whether this be the fact, or not, it might be difficult to 

 determine; but it is well known that, if land which is irrigated 

 be not also thoroughly drained^ it will, when pastured, occasion 

 that fatal malady. Although no irrigated meadows can be said 

 to be quite safe for sheep in the autumn, they are yet generally 

 considered to be free from danger in the spring : but when the 

 drainage has not been duly performed, they have been know^n to 

 cause the rot in all seasons ; and it has in many cases been found 

 necessary to deepen the drains, for the purpose of completely 

 removing the water. 



Some startling facts on this subject are stated in a very interest- 

 ing publication regarding the extraordinary success of irrigation 

 on the estate of the Duke of Portland, in Nottinghamshire. One 

 of which mentions that ewes and lambs fed upon a piece of land 

 which had been drained in 1826, and regularly irrigated, invari- 

 ably gave them the rot in spring; until, in 1837, it was more 

 effectually drained, and the out-fall rendered complete : since 

 which all appearance of the disease has ceased. 



It is there laid down as an axiom demonstrated by a long course 

 of experiments, ''^ that a complete and perfect drainage of the 

 bottom-water is absolutely necessary ; its noxious effects showing 

 themselves at a depth and under circumstances which could 

 hardly be credited by any but those who have actually witnessed 

 them." It then says, it is not uncommonly held by persons 

 conversant with draining, that, if the land is filled with shallow 

 drains, so that no top-water can lodge, and that all bottom-ivater 

 which should rise to the level of those drains should be carried off, 

 then all that is, necessary has been clone. But if, instead of 

 shallow drains at 20 inches, the case should be put of land well 

 filled with drains at 5 feet deep, it would be doubted by few that 

 such land would certainly be secured from all the bad effects of 

 bottom-water." The account, however^ mentions instances to the 

 contrary, which it is unnecessary to copy ; but it concludes by 

 stating, that to effect a perfect drainage, spring -water pressing 

 upon the land should in all cases be cut off ; and, in land to be 

 watered, a more thorough drainage is requisite than for any other 

 purpose the truth of which no one who really understands the 



* John Evelyn Denison, Esq., on the "Duke of Portland's Water- 

 Meadows at Clipstone Park." — This Journal, vol. i. art. 39. 



See also the " Quart. Journal of Agric.,"' vol. v. p. 503, in which an in- 



