TILE AND PIPE DRAINING. 123 



The rock, which is of the grauwacke slate, comes near the sur 

 face, and in some instances prevented the drains being cut as 

 deep as might have been wished. The average height of the 

 land drained is about 200 feet above the level of the sea, with a 

 western aspect. The higher portion of it, previous to being 

 drained, was wet, shallow, and sterile, and the lower part a heavy, 

 stiff clay, which, in unfavorable seasons, was almost impossible 

 to prepare for drilled crops. The effect of the drainage on all 

 this land is very conspicuous, particularly on 140 acres which 

 have been subsoiled. The land is now a deep and free soil, pro 

 ducing excellent crops of potatoes, turnips, and carrots, when pre 

 viously it was quite unsuited to drilled crops. 



&quot; I would, however, from any conclusions I can draw from 

 experience, beg to recommend, in ordinary cases, where the rock 

 does not interfere, and where sufficient fall can be obtained, that 

 the drains should be cut at least three feet deep, and that tiles 

 and soles, or pipe-tiles, should be used in preference to stones, 

 both as to efficiency, and above all to permanency. 



I am fully satisfied, in the greater number of instances, that 

 much expense may be spared in materials for filling, by increasing 

 the distance between, and adding to the depth of the drains. One 

 great advantage in favor of the deep drains is, that they are cal 

 culated to be more permanent, and that, while in wet weather 

 they discharge fully as much water, they continue in operation 

 a much longer time, and in many instances continue to give out 

 water for weeks after the shallow drains have ceased to discharge 

 upon similar soils. 



&quot; The following is a description of the manner in which the 

 drains at Ballyleidy have been executed : The submains are 

 laid off on a considerable declivity, and cut six inches deeper 

 than the parallel drains, with a slate and a large tile laid in the 

 bottom of each, with stones carefully coupled over the tiles, and 

 six inches of broken stones placed over all, then neatly turfed. 

 Iron grates are built in at the mouths, where these submains 

 discharge, so as effectually to prevent the entrance of any kind 

 of vermin. I am now satisfied that the most permanent sub- 

 mains are two tiles reversed, forming a pipe, and thus confining 

 the water so as to give it force and pressure, to clear away all 

 obstructions. 



&quot; The parallel drains were neatly cut, and. where stones were 



