694 



PRACTICE OF AGRICULTURE. 



Part III. 



description, or such as are of a marshy and boggy nature, from the detention of water 

 beneath the spongy surface materials of which they are composed, and its being absorbed 

 and forced up into them, are constantly kept in such states of wetness as are highly im- 

 proper for the purpose of producing advantageous crops of any kind. They are, there- 

 fore, on this account, as well as from their occupying very extensive tracts in many districts, 

 and being, when properly reclaimed, of considerable value, objects of great interest and 

 importance to the attentive agricultor. Wet grounds of these kinds may be arranged 

 under three distinct heads : first, such as may be readily known by the springs rising out 

 of the adjacent more elevated ground, in an exact or regular line along the higher side 

 of the wet surface ; secondly, those in which the numerous springs that show themselves 

 are not kept to an exact or regular line of direction along the higher or more elevated 

 parts of the land, but break forth promiscuously throughout the whole surface, and par- 

 ticularly towards the inferior parts {Jig. 625. a), constituting shaking quags in every 

 direction, that have an elastic feel under the feet, on which the lightest animals can 

 scarcely tread without danger, and which, for the most part, show themselves by the 

 luxuriance and verdure of the grass about them ; and, thirdly, that sort of wet land, from 

 the oozing of springs, which is neither of such great extent, nor in the nature of the soil 

 so peati/ as the other two, and to which the term bog cannot be strictly applied, but which 

 in respect to the modes of draining is the same. {Johnston's Account of Elkingtons Mode 

 of Draining Land, p. 19.) 



4235. In order to direct the proper mode of cutting the drains or trenches in draining 

 lands of this sort, it will be necessary for the draining engineer to make himself perfectly 

 acquainted with the nature and disposition of the strata composing the higher grounds, 

 and the connection which they have with that which is to be rendered dry. This may 

 in general be accomplished by means of levelling and carefully attending to what has 

 been already observed respecting the formation of hills and elevated grounds, and by in- 



specting the beds of rivers, the edges of banks that have been wrought through, and such 

 pits and quarries as may have been dug near to the land. Rushes, alder-bushes, and other 

 coarse aquatic plants, may also, in some instances, serve as guides in this business ; but 

 they should not be too implicitly depended on, as they may be caused by the stagnation 

 of rain-water upon the surface, without any spring being present. The line of springs 

 being ascertained, and also some knowledge of the substrata being acquired, a line of 

 drain {Jig. 625. b, b) should be marked out above or below them, according to the nature 

 of the strata, and excavated to such a depth as will intercept the water in the porous 

 strata before it rises to the surface. The effect of such drains will often be greatly 

 heightened by boring holes (c) in their bottom with the auger. Where the impervious 

 stratum {Jig. 626. a), that lies immediately beneath the porous (6), has a slanting direction 



through a hill or rising bank, the surface of the low lands will, in general, be spongy, 

 wet, and covered with rushes on every side (c). In this case, which is not unfrequent, 

 a ditch or drain (d), properly cut on one side of the hill or rising ground, may remove 



