ON DRAINING. Ill 



previous to ploughing- it up for tlie sowing- of grain. It is, 

 however, during- the period iu which a field is in grass, and 

 immediately before breaking- it up for oats, that most farmers 

 in this cp;arter prefer to drain it, for the following-, among" 

 other reasons ; viz. that the stones emplo3'ed in filling- are 

 then carted to the drains with less difficulty and labour to 

 the horses, and less injury to the land; and that they can 

 he broken and filled in more cleanly and expeditiously than 

 •when the ground is soft and loose on the surface; besides, 

 when the field is in grass at the time of draining, suitable 

 turf can very conveniently be obtained for covering- the 

 stones previously to putting- in the earth. 



3Iain Drains. — In beginning to drain a field or piece of 

 land, the situation, direction, and dimensions of the main 

 drains or leaders first demand the careful consideration of 

 the farmer. Their number and position are of course regu- 

 lated in a great degree by the nature of the surface ; and 

 their dimensions are determined chiefly by the extent of 

 land whence they are intended to receive water, the degree 

 of wetness, and other obvious circumstances. They are 

 invariably made several inches deeper than the small or 

 parallel drains, for the purpose of affording the water a 

 sufficient fall from the latter, and thereby preventing the 

 accumulation of sediment at the junction of the drains with 

 their leader, which, it is obvious, would soon render them 

 partially inoperative. Main di-ains, constructed in the man- 

 ner to be presently described, are generally fi-om 3 to 3^ 

 feet in depth, from 15 to 18 inches in width at the bottom, 

 and a proportionate breadth -at the top. The depth just 

 mentioned is considered quite sufficient for main drains, 

 when the branch ones that fall into them are only from 

 30 to 33 inches deep; but, of course, the depth of the 

 former must be increased in proportion to that of the 

 latter. It is hardly necessary to state that the main-drains 

 are always opened before the cutting of the smaller ones 

 that are to be led into them is commenced, but that the 

 latter are generally filled in before the former, the propriety 

 and object of which must be known to every reader. The 

 following is the usual mode of constructing- main drains : — ■ 

 After the cutting and filling of the whole of the smaller 

 drains are completed, and it has been observed that a suffi- 

 cient and uniform fall is secured for the water, both into and 

 from the main drain, a low wall is built with flat stones at 

 each side of the bottom of the latter ; openings being, of 



