TILE AND PIPE DRAINING. 121 



&quot; The parallel drains are at least 30 inches deep, with 12 inches 

 of small stones ; the submains are 6 inches deeper, laid with 

 slates and tiles, and filled with stones to the level of the parallel 

 drains, and both are carefully levelled, turfed, and firmly 

 tramped; and the mains, flagged in the bottom, built with dry 

 masonry, and covered with coarse flags, are placed at depths, and 

 constructed of dimensions, in all cases exceeding what Mr. Smith 

 has considered sufficient to carry off the entire water from the 

 submains, during and subsequently to the heaviest falls of rain. 



&quot; The soil, as stated in last Report, rests on the grauwacke 

 slate formation, and the subsoil, as described by Mr. Smith. 

 t consists chiefly of a clay drift, with gravel stones thickly inter 

 spersed, and occasional boulders of considerable size. 



&quot; The work of thorough draining of every year has been fol 

 lowed up in the succeeding year by subsoil-ploughing. All the 

 land drained in 1843 was subsoiled and in green crops in 1844, 

 and that drained in 1844 has been undergoing the process of 

 subsoiling, which will soon be completed.&quot; 



&quot; As regards the profits to be derived from capital expended 

 in thorough-draining,&quot; these gentlemen say, &quot; our experience 

 fully realizes our largest expectations. In green crops the 

 increased return is most conspicuous. In und rained land in a 

 wet year, potatoes and turnips have ever proved wretched crops ; 

 and all attempts to clean the ground have invariably failed. In 

 1840, our crop of potatoes on wet land did not exceed 200 bush 

 els per Cunningham acre ; this year we ascertained, by actually 

 weighing, on the weigh-bridge, the entire crop of potatoes, of the 

 kind called cups, from field No. 4, containing above 17 statute 

 acres, (excluding the head lands from the calculation, both as to 

 crop and measurement,) that the produce was, 



Tons. Cwt. 



Per statute acre, 472 bushels, of 56 Ibs. each, or 1 1 16 

 Per Cunningham or Scotch acre, 610 . . . .15 5 

 Per Irish acre, 766 19 3 



&quot; And on field No. 7, several trials were made of drills dug the 

 length of the field, the kinds being lumpers and other coarse 

 varieties ; and the produce was at least one sixth greater than that 

 of the cups. 



&quot; This we regard as very great produce, arid the difference 

 11 



