DRAINING. 



73 



Draining ground through the subsoil unto the retentive bottom, 

 """V* and filled with retentive materials, as loamy earth, &c. 

 The furrows and ridges should also lie in that direction ; 

 and it would be proper in great declivities, I o cultivate the 

 soil in beds or terraces, the surface of which might be 

 laid level. This practice is adopted in various mountain 

 countries. 



In these two last cases, where the country is flat and 

 low, so that when the water stands in the ditches, the 

 subsoil is gorged up with moisture, a disease of a diffe- 

 rent kind is produced. Land of this kind is among the 

 most worthless that we know. In wet seasons, the rank 

 aquatics take possession, and the site, if left to nature, 

 would be speedily covered by moss, though, in dry sea- 

 sons, the crops are scorched to the root by the sun and 

 air. 



The remedy, as in Case 2d, is to lower the outfall, by 

 running drains in the subsoil. Care must be taken to 

 prevent the sand from running into and choking them, 

 and to lay them so as to preserve the bottom from in- 

 jury. 



If the outfall cannot easily be lowered, the soil should 

 be laid in high beds, by excavating one part of it, and 

 making up the other ; thus acquiring a portion of dry 

 land at the expence of a part of the surface. 



Case 6th, The Subsoil and Bollom impervious. Sand, 

 Gravel, or Loam, upon Clay. Light Moss upon black 

 Peat. 



Open soils. This case, although possessing the same soil or culti- 



" th subsoil vated stratum as the two last, differs greatly from them 



in quality. In wet seasons, the crop is liable to be chil- 



led, by the water lodging at the roots, and in the vegeta- 



tive stratum, until carried off by evaporation. Aquatic 



weeds rise fast, and the soil is unfit to bear the tread of 



cattle, especially during winter. In dry seasons, the soil 



is scorched by evaporation, and can derive no moisture 



from below, so that the crops are stunted or blighted. 



The remedy is to open the subsoil by trenching and 

 fallowing, as recommended in Case 1st, to which this has 

 a great resemblance. Or the soil may be laid up in beds 

 or high ridges, running across the slope with a gentle de- 

 clivity, that the surplus water may be carried off in the 

 furrows, while the soil is so far deepened, as to retain a 

 supply of moisture in its pores for a longer period. This 

 is the method usually practised in Ireland and in Flan- 

 ders. Or hollow drains may be formed in the subsoil, 

 running also across the slope, as is practised in Essex. 

 Sod drains will answer well enough in such cases. If the 

 lower soil be of good quality though retentive, a portion 

 of the upper porous soil may be turned down by trench- 

 ing. 



In moss not thoroughly reclaimed, if the beds or rid- 

 es be high, the water passes too quickly away, especial- 

 ly when the land is in corn. It is better, therefore, in 

 that kind of soil, to preserve the ridges pretty broad and 

 flat, as a perch wide, and 10 inches high, but at the same 

 time to prevent surcharge, by particular attention to the 

 water furrow ; and in all cases ft must be observed, that 

 every variety of soil requires a corresponding variation in 

 the mode of management. 



Case 7th.. Subsoil retentive bottom oj>en. The lack lea of 

 Ireland, a hard Clayey Stratum below the Soil, covering 



unuve.bot- 



tODi open. 



-phis ras?j ; n j ts na t ur al state, resembles the last, but it 



VOL. VIII. PART I. 



admits of a ready cure ; for, if the clayey stratum be Draining, 

 pierced, the water passes immediately off by the bottom, V T~"' 

 But it is difficult to provide against drought. No reme- 

 dy seems so obvious, as that of laying up the soil in beds 

 so as to deepen it, while each alley may have holes pier- 

 ced through the clayey stratum, so as to secure an effec- 

 tual drainage during wet seasons, but be readily stopped 

 up in case of drought. Or what would perhaps be still 

 better, to trench up a portion of the gravel, to form a 

 new subsoil over the first, and thus bring the case to No. 

 2. or 5. 



Of the different kinds of Hollow Drains. 



Before we proceed to the next division of our subject, Differeat 

 we shall give a description of the different kinds of subsoil kinds of hoi - 

 drains which are at present in use in different parts of drains, 

 these kingdoms. 



Though open drains are perhaps the most eligible, for 

 conveying the superabundant rain water from the surface 

 where it falls, or for conveying the waters collected from 

 the soil into the stream or river, they are by no means 

 so advisable in drawing water from the subsoil, especial- 

 ly in lands under tillage. The substratum where the 

 water issues is generally loose, and might slip into the 

 open drain ; and the tread of cattle is at all times injuri- 

 ous. Where the drain is intended to collect the water at 

 its sides from the stratum in which it is formed, a cer- 

 tain depth of open materials is required for filling it, 

 which is generally procured, by collecting the small stones 

 in the field. These are termed "rumbling rivers" in 

 some parts of Scotland. In Ireland, they are usually 

 known by the name of French drains. 



But where intended as an aqueduct or channel for wa- 

 ter, collected from springs or other sources, it is advisable 

 to form the drain hollow, by constructing a pipe or open 

 channel along the bottom, and an absorbent stratum may 

 be formed over it, so as to combine the advantages of 

 both. In some cases, as where drains are filled with straw 

 or brushwood in firm earth, the drain at first is of the 

 former, and, after these substances decay, becomes of the 

 latter description. 



In the eastern parts of England, where stone is scarce, 

 and the wet bottoms were in most cases covered by cop- 

 pices, it is likely that drains were first filled by putting 

 three poles triangularly over each other in the bottom of 

 the trench. Of late years brushwood has been much em- 

 ployed, and even straw trampled in or formed into ropes. 

 Black thorns are found particularly durable; but where- 

 ever hard materials are easily procured, as pebbles or 

 small stones, they are justly preferred for the formation 

 of permanent drains. 



The trench for the filled drain is formed by the plough 

 or spade. In the former case two furrows are drawn, so 

 as to leave a baulk between them of 1 5 inches wide ; then 

 with a strong double breasted plough made on purpose, 

 that baulk is split, so as to leave a clean furrow 14 or 15 

 inches beneath the surface, or even by a second plough- 

 ing to the depth of 20 inches; it is then ready for 

 the draining or land ditching spade, with which a nar- 

 row drain is dug of 15 inches deep. A scoop is als 

 sometimes employed, for clearing out the loose materials 

 in the bottom. These dimensions vary with the requi- 

 red depth and the plenty of materials. 



When the drain is formed, it is next to be filled with 

 such materials as the situation affords, the depth of which 

 will of* course be regulated by the supply of water. Fif- 



