866 THE COMPLETE GRAZIER. BOOK ix. 



channels thus made in the land deliver into properly constructed main 

 drains with pipes of sufficient size. The implement can only be used 

 satisfactorily on homogeneous clays, or free loams, and is better suited 

 to grass lands than to arable soils. 



Sod- or turf- drains, which have been adopted on tenacious grass 

 lands, are thus formed : A wedge-shaped sod or piece of turf is cut 

 from the furrow or line of the intended drain, the point of the wedge 

 is cut off, and the turf or sod then again inserted into the soil. But 

 land in which drains of this sort are used is never sound, or fit for 

 cattle. 



In all cases, the apertures or mouths of drains should be effectually 

 guarded by a railing, or grating, to prevent the watercourse from 

 being obstructed ; and the passage for the water should uniformly be 

 narrow at the bottom, as the pressure of the flowing liquid will be fully 

 adequate to remove any accidental impediments to its course, and 

 consequently such drains will be more durable. 



Where materials are dear, stone drains may be resorted to with 

 advantage. They should be cut 10 or 12 inches wide, with per- 

 pendicular sides, and lined with flat stones so disposed as to leave a 

 watercourse at the bottom, by setting two of them in such a manner 

 as to meet triangularly at the edges. The cavity of the drain should be 

 filled nearly to the top with loose stones, for which coarse-screened 

 gravel may be advantageously substituted, where a sufficient quantity 

 can be obtained. In loose sandy or peaty soils, where earth drains 

 would last but a short time, pipes or tiles should be employed. The 

 expense of these was formerly an obstacle to their being employed to 

 any extent, but now, by the aid of improved machinery, they are within 

 the reach of all agriculturists. 



The varieties of soils met with in the practice of draining may be 

 classified thus : 1st, Light soils : light gravelly loam, light marly loam, 

 sandy loam, soft light loam, sandy soil, light gravelly sand, deep 

 gravelly sand, coarse gravelly sand, loose gravelly sand. 2nd, Medium 

 soils : clayey loam, marly loam, gravelly loam, friable loam. 3rd, 

 Heavy soils: compact tenacious gravelly clay, soft adhesive clay, free 

 soft clay. The practice of draining may be divided into three classes 

 of operations, respectively concerned with : first, the laying out and 

 direction of the drains ; secondly, the depth of the drains ; thirdly, 

 the distances between the drains. To these may be added the con- 

 siderations of fourthly, the materials used in the construction of the 

 drains ; and fifthly, the cost of the drains. The laying out and the 

 direction of the drains has been a subject of considerable controversy, 

 two opinions having been brought forward ; namely, on the one hand, 

 that the direction of the drains should be in the line of greatest fall, in 

 the slope of the ground ; and, on the other hand, that the drains should 

 be transversely to, or across, the fall or slope of the ground. The 

 weight of evidence is decidedly in favour of the first mode, namely, 

 running the drains in the direction of the slope. 



Of the first mode, according to Mr. Smith of Deanston : " Drains 

 drawn across a steep, cut the strata or layers of subsoil transversely, 



