102 THOROUGH-DRAINING. 



abstracting" the water and admitting- air instead, the soil, hut 

 especially the clay, contracts to the depth at which the 

 water is drawn off, and, in contracting", many small fissures 

 or veins are formed, which serve as channels for the water to 

 reach the bottom of the drain. To leave theory, however, 

 as we are all jiractical people here, I will tell you what I 

 have myself seen : a field had been drained at the depth of 

 two feet from one side to the other, still it did not produce 

 the effect of drying" the land so quickly as had been expected: 

 the owner h-ad a few drains cut here and there at a depth of 

 four feet : after a heavy rain, I, along- with others, went to 

 examine the field : we found a small run of muddy water 

 from some of the shallow drains, but a copious one of clear 

 water from all the deeper ones, showing- that, in its descent 

 to them, it had not robbed the soil of any of its finest parts, 

 as was the case in the shallow drains, and that it was 

 escaping- much faster from the land. You will find it also 

 recorded, from most authentic information, in the Journals 

 of the Ag-ricultu)-al Society, that the water drawn from an 

 acre of land in an hour, drained at a depth of four feet, was 

 one-third more than from another adjoining- acre with two- 

 feet drains, and that the run began sooner, after the fall of 

 rain, in the deeper drains, and of course also ceased sooner, 

 than in the shallow ones. M}^ own opinion is, that in hardly 

 an}' case should tiles be laid at a less depth than three feet, 

 but that in many cases four feet would be preferable. The 

 expense should be estimated more by the efficiency of the 

 operation than the outlay of money; but, even in respect of 

 expense, the balance is in favoiu" of the deeper draining- ; for, 

 if drains three feet deep and thirty feet apart ai-e more 

 efficacious than those of two feet deep and twenty feet aj)art, 

 the former comes cheaper by the acre, as there is only one 

 foot more of soil to remove in the deeper drains than in the 

 shallower, against which is to be set the saving- in the pur- 

 chase and carting- of one-third of the tiles. It is, of course, 

 impossible that one rule can be applicable to all situations. 

 Much must be left, in every case, to the kind of subsoil 

 which is met with : in some })laces seams of sand are found 

 intersecting- beds of clay, and then probably one deep drain 

 may lay a whole acre dry better than many shallow ones 

 would. There is one description of subsoil common in this 

 county, in which I think it may be advisable to make the 

 drains frequent and shallow, rather than deep and more 

 distant, because it is so firm and hard, that I believe no 



