Y04 



PRACTICE OF AGRICULTURE. 



Part III. 



ing body of clay ; the consequence of which is, that the porous open soil above is so 

 filled and saturated with water, as to be of little utility for producing crops of either 

 grain or grass. Land thus situated is frequently said by farmers to be wet-bottomed. 

 In order to remove this kind of wetness, it seldom requires more than a few drains, made 

 according to the situation and extent of the field, of such a' depth as to pass a few inches 

 into the clay, between which and the under surface of the porous earth above there will 

 obviously be the greatest stagnation, and consequently the largest collection of water, 

 especially where it does not become much visible on the surface. In these cases there is 

 no necessity for having recourse to the boring instrument, as there is no water to be dis- 

 charged from below. 



4268. IF/ien the Jield to he drained has only a slight declination, or slope, from the sides 

 towards the middle, one drain cut through the porous superficial materials into the clay, 

 in the lowest part of the ground {fig. 638. a), may be sufficient to bring off the whole of the 

 water detained in the porous soil. This effect may likewise be greatly promoted, by laying 

 out and forming the ridges so as to accord with the direction of the land, and by the use 

 of the plough or spade in removing obstructions, and deepening the furrows. In such 

 638 situations, where the drain has been formed 



jj in this manner, the water will flow into it 

 % through the porous surface materials, as 

 well as if a number of small trenches were 



^ 



^ 



^ cut from it to each side, as is the practice 

 ^ in Essex and some other parts of the coun- 

 ^ try ; but which is often an unnecessary 

 |- labour and expense. The drain made in the 

 1^ hollow may frequently serve as a division of 

 the field (a), in which case it may be open ; 

 but in other circumstances it may be more proper to have it covered. 



4269. Where a field of this description has more than one hollow in its surface (fig. 639. 

 a, b), it will obviously be requisite to have more than one main drain ; but when it is nearly 

 level, or only inclines slightly to one side, a trench or drain along the lowest part, and 



639 



the ridges and furrows formed accordingly, may be sufficient for effecting its drainage. 

 There may, however, be cases, as where a field is large and very flat, in which some side- 

 cuts from the principal drain may be necessary, which must be made a little into the 

 clay, and as narrow as they can be wrought, and then filled up with stones or other suit- 

 able materials. 



4270. IFhat is called the Essex method of draining in ploughed springy lands, where the 

 surface soil is tenacious, is described by Kent, and consists in substituting small under- 

 drains {fig. 640. a) for open furrows ; or in some cases having a small under-drain beneath 



640 



(b) every other or every third furrow. These drains lead to side or fence ditches (c), 

 where they discharge themselves. 



4271. Where the clay constitutes the surface, and the porous body is underneath, the m- 

 jurious stagnant water cannot possibly get off, without the assistance of drains formed 

 for the purpose. Soils of this nature are drained with difficuky, and require a much 

 greater number of trenches or cuts than those of any other kind, as they must be marked 

 out and disposed in such a way as to collect and convey the water every where from the 

 surface j because it can only force itself off into them from above, being prevented from 



