638 PRACTICE OF AGRICULTURE. Part III. 



drained in Kent and Hertfordshire. {See the Reports of these Counties. ) In marl- 

 pits also, which, from the nature of their situation, mostly require much cutting 

 through some part of their sides, in order to remove the water that prevents their being 

 wrouo-ht, the mode of letting the water down by means of pits dug through the up- 

 holding stratum below the bed of marl into the porous materials underneath, might be 

 economically practised. In such cases, the number of the pits must be proportioned to 

 the space occupied by the marl ; and when they are required to be of such depths as to 

 be liable to give way, they should be built up, or nearly filled with loose stones, so as to 

 admit the water to pass oft'; such lateral drains as are necessary communicating with 

 them. In some situations of the pits, as where the bank slopes lower on the contrary- 

 side than the level of the water, an easier mode may be practised ; such as by forming 

 a drain in it, and then perforating with a horizontal boring instrument into the ter- 

 minating part of the stratum that holds the water ; thereby removing and keeping it 

 below the level of the marl. And in addition to these, in some cases, as where the 

 water of such pits proceeds from springs in the high grounds above them, it may be 

 useful to intercept and convey it away before it reaches the marl-pits. 



Sect. VI. Of the Formation of Brains, and the Materials used in filling them. 



39.57. Drains should be formed with as much truth and exactness as jwssible ; such 

 laborers as are not dexterous in using their tools seldom make them well. The most 

 general method of performing this sort of work is by admeasurement, at so much a 

 rod, or a score rods, which necessarily induces the workmen to do as much as they pos- 

 sibly can ; they should, therefore, be frequently inspected, to see that they keep to the 

 proper and required. depth, and that the earth taken out be laid in such a manner as not 

 to fall down again into the drains in time of filling them, and that the surface-^mould be 

 kept on one side free from the clayey or other material of the inferior stratum. 



3958. When there is any declivity in the ground, drains should be made in a slanting 

 direction across it, instead of the old method of conducting them according to the nature 

 or inclination of the slope. By attending to the former mode of cutting the drains, the 

 wetness is not only more effectually removed, but, by allowing the water to pass away 

 in an easy current, they are rendered less liable to be choaked, or, as it is frequently 

 termed, blown up, by which artificial oozings of water are sometimes formed in such 

 places. But where grounds are either quite or nearly level, it has long been a general 

 practice to cut the drains at the different distances of about sixteen, twenty-four, and 

 thirty-two feet from each other, across the fields from the different ditches, according to 

 the circumstances of the lands ; or, indeed, where the drains, either from some slight 

 unevenness of the surface, or other causes, can only be made to flow at one end, to 

 avoid cutting them further on one side than where the ditch is capable of taking away 

 the wetness. In cases where the declivities of a piece of ground are various, and have 

 different inclinations, the drainer should constantly attend to them, and direct the lines 

 of his drains in such a manner as that they may cross the higher sides of the different 

 declivities in a slanting direction. 



3959. The depth of drains must depend upon the nature of the soils, the positions of 

 the land, and a great variety of other more trifling circumstances. It was formerly the 

 custom to make them three or four feet in depth, but by modern drainers they are 

 rarely made to exceed thirty inches, or a few inches more, the most general depth being 

 from twenty-four to twenty-six inches. As the main drains have more water to 

 convey away,* and are generally of greater length than thfe lateral ones, they should 

 always be cut somewhat deeper ; and where the materials of the soils are porous, the 

 greater depth they are cut, the more extensively they act in lowering the wetness of the 

 land to such a degree as that it can be little injurious to the crops that may be produced 

 upon it : when, however, the operator reaches any impervious material in the soil, 

 through which the moisture cannot pass, it will be quite useless to dig the trench to a 

 greater depth. If it be clay, by going a few inches into it, a more safe passage for the 

 moisture may however be secured. It must notwithstanding be invariably attended to, 

 that the depth of the drains be such as that the treading of heavy cattle may not displace, 

 or in any way injure, the materials employed in constructing or filling them. It may 

 be noticed too, where the horses in ploughing tread in the bottom of the furrow, at the 

 depth of four or more inches below the surface, that, if eight or ten more be allowed for 

 the materials with which the drains are filled, when the depth of the trenches are not more 

 than twenty-four inches, there will only be nine or ten inches of earth for the support of 

 the horses when ploughing. Where the earth has been stirred, such a depth must un- 

 doubtedly be too little, and in some measure proves that drains of such a depth are not 

 sufficient. By cutting them down to the depth of two feet and a half in the stiffer soils, 

 they will seldom be penetrated to, or have too great a depth ; and in the pervious ones a 

 still greater depth is highly useful, and constantly to be practised. 



3960. The practice of cutting the drains as narrow as possible, which has lately 

 been much attended to, is of importance, as it causes a considerable saving of the 



