632 PRACTICE OF AGRICULTURE. Part III. 



water is slow, and its surface nearly equal with that of the land, than where its descent is 

 rapid. Under such circumstances, while the river or brook remains at the ordinary 

 height, no advantage can be gained, whatever number of drains be formed, or in what- 

 ever direction they may be made. The chief or only means of removing the wetness of 

 land proceeding from this cause is, that of enlarging and sinking the bed of the stream, 

 where it can be eiFected at a reasonable expense : where there is only one stream, and it 

 is very winding or serpentine in its course, much may however be effected by cutting 

 through the different points of land, and rendering the course more straight, and thereby 

 less liable to obstruct the passage of the water. But in cases where there are more than 

 one, that should always be made the channel of conveyance for draining the neighbor- 

 ing land, which is the lowest in respect to situation and the most open and straight in its 

 course. It may likewise, in particular instances, be advantageous to stop up and divert 

 the waters of the others into such main channels, as by such means alone they may often 

 be rendered deeper, and more free from obstruction : the materials removed from them 

 may serve to embank and raise up the sides to a greater height, as while the water can 

 rise higher than the outlets of the drains, and flow backwards into them, it must render 

 the land as wet as it was before they were formed, and the expense of cutting them be 

 thrown away. 



3937. The collected rain-water becoming stagnant on a retentive body of clay, or some 

 other impervious material, as it can have no outlet of the natural kind, causes such lands 

 to become soft and spongy, thus forming bogs of a very confined kind. As such bogs 

 are often situated very greatly below the ground that surrounds them, the opening of a 

 main drain, or conductor, to convey off the water collected by smaller drains, would be 

 attended, in many instances, with an expense greater than could be compensated by the 

 land after it had been drained. The thickness of the impervious stratum that retains and 

 keeps up the water in such cases is often so great, that though the stratum below be of a 

 porous and open nature, such as sand, rock, or gravel, the water cannot of itself penetrate 

 or find a passage from the one into the other ; consequently, by its continued stagnation 

 above, all the different coarse vegetable productions that have for a great length of time 

 been produced on its surface, and probably the upper part of the soil itself, are formed 

 into a mass or body of peat earth, equally soft and less productive than that of any bog 

 originating from water confined below, and which is only capable of sustaining the 

 weight of cattle in very dry seasons, when the wind and sun have exhaled and dried up a 

 great part of its surface moisture ; but even then it is incapable of admitting the plough 

 upon it. 



3938. As the cause of these kinds of bogs is materially different from that of those which 

 have been already noticed, their drainage must of course be accomplished in a different 

 way. The following method of proceeding is recommended as perhaps the least ex- 

 pensive. In the middle, or most depending 

 part of the ground, the first drain (fg. 488 a), 

 may be cut, into which all the others should 

 be made to lead ; the number and direction 

 of which must be regulated by the extent of 

 the bog. They should be cut through the 

 peat, or moist spongy upper soil, to the sur- 

 face of the clay, or other retentive stratum of 

 materials, which must then be perforated or 

 bored through in order to let the water down 

 into the pervious stratum below, by which it 

 may be absorbed and taken up. The same 

 feffect might be produced by forming one 

 large well, or pit, in the middle or lowest 

 part of the bog, by digging through into 

 the porous stratum below, and connecting the other drains with it, as by such a method 

 the trouble and expense of boring along the drains would be saved. In these cases, 

 when drains are made, they should always be cut as narrow as it is possible to make 

 them, and after the holes have been formed in them by boring, filled up with loose stones 

 to within about a foot and a half of the surface, which space may be made up by a por- 

 tion of the earth that had been taken out, putting in turf with the green side to the 

 stones before the earth is thrown in. By this means the water and prejudicial moisture 

 of the peat, or upper soil, may be taken away by the drains, and pass off through the 

 holes that have been formed in their bottoms. But where pits are employed, these 

 should only be filled with small stones to the level of the bottom of the drain, the filling 

 being performed as soon as possible after they are formed [Anderson s Treatise on Drain- 

 ing, p. 88.) ; where there is a chalky stratum below, after taking it out, the flints con- 

 tained in itmaylje made use of in this way with much advantage; and where the drains 

 can be carried into quarries, where the stone is much fissured, notliing more will be ne- 

 cessary. Where land of this sort is afterwards to be ploughed, great attention should be 



