640 



PRACTICE OF AGRICULTURE. 



Part III. 



aid cf a machine 

 504 



care to fill them up as well as possible, and not to permit any clay to be laid over the stones. This has 

 proved effectual." {Loch.) 



3967. The gravel or cinder drain is seldom made deep, though, if the materials be 

 large, they may be made of any size. In general they are used in grass lands; the 

 section of the drain being an acute angled triangle, and the materials being filled in, the 

 smallest uppermost, nearly to the ground's surface. 



3968. The wood drain is of various kinds. A very sufficient and durable construction 

 consists of poles or young fir-trees stripped of their branches and laid in the bottom of the 

 drain lengthways. They are then covered with the branches and spray. Another form is 

 that of filling the drain with faggot-wood with some straw over. A variety of this 

 mode {jig- 503.), is formed by first setting in cross stakes to prevent 503 

 the faggots from sinking ; but they are of no great use, and often 

 occasion such drains to fail sooner than common faggot drains, by 

 the greater vacuity they leave after the wood is rotten. In some 

 varieties of this drain the brush-wood is first laid down alongside the 

 drain and formed by willow or other ties into an endless cable of 

 ten or twelve inches in diameter and then rolled in, which is said to 

 form an excellent drain with the least quantity of materials, and to 

 last a longer time than any of the modes above mentioned. Some 

 cut the brush- wood into l^gths of three or four feet, and place them 

 in a sloping direction with the root end of the branch in the bottom 

 of the drain ; others throw in the branches at random with little pre- 

 paration and cover them with spray, straw, or rushes, and finally the 

 surface soil. 



3969. The spray drain is generally like the gravel drain, of small size, and formed 

 like it, with an acute angled bottom. In general, the spray is trod firmly in ; though in 

 some cases it is previously formed into a cable, as in the brush-wood drain. Drains of 

 this sort are much in use in grass lands, and when the spray of larch wood, heath, or ling 

 can be got, they are of great durability. 



3970. The straw drain, when reeds, rushes, and bean straw is used, is sometimes made 

 like the spray drain, by pressing the loose material down, or forming a cable ; but in ge 

 neral the straw is twisted into ropes as big as a man's leg, by the 

 (2457.), and three or more of these {fig. 504 a) laid in the bottom of 

 a triangular drain, with or without the protection of three turves (b). 

 Where some sorts of moss, as sphagnum or lycopodium can be got, 

 these drains are of unknown durability. Drains formed in this man- 

 ner, through tough and retentive clays, will be found in a short time 

 after the work is finished, to have formed over the straw with which 

 the drain was filled, an arch of sufficient strength to support the in- 

 cumbent weight of the soil, and the casual traffick of the field. In 

 twelve or eighteen months it may be observed, that the straw, being 

 of one uniform substance, is all rotted and carried away, leaving a 

 clear pipe through the land in every drain. The passage of the 

 water into these drains may be much facilitated, by a due attention to 

 filling them with the most friable and porous parts of the surface the field may 

 afford. 



3971. The turf drain {fig. 505.), may be made of 



^' any convenient depth, but it must beat leastthe breadth 

 of a turf at bottom. The drain being dug out as if it 

 were to be filled with stones or any ordinary material, 

 the operator next, with a spade three inches wide, digs a 

 narrow channel along its centre (a), clearing it out with 

 the draining scoop ; and over this the turves [b) are laid 

 without any other preparation, or any thing put over 

 them but the earth that was excavated. This is found 

 to be a very cheap, and, considering the materials, a 

 surprisingly durable method of draining ; answering, in 

 pasture-fields especially, all the purposes that the farmer 

 can expect to derive from drains constructed with more labor, and at a much greater ex- 

 pense. They are said to last frequently twenty years and upwards : but the period 

 which it can be supposed they will continue to prove effectual, must depend on the nature 

 of the soil and the current of watier. 



3972. The triangular sod drain is thus made : when the line of drain is marked out, 

 a sod is cut in the form of a wedge, the grass side being the narrowest, and the sods 

 being from twelve to eighteen inches in length. The drain is then cut to the depth re- 

 quired, but is contracted to a very narrow bottom. The sods are then set in with the 

 gras side downwards, and pressed as far as they will go. As the figure of the drain 



