DRAINING. 



721 



fords an interesting example of successful drainage 

 of mixed soil and strata. It was begun in 1815, 

 under the direction of Mr Stephens, an eminent drain- 

 ing engineer, and author of a useful work on the sub- 

 ject (The Practical Irrigator, fyc., Edin. 8vo, 1829) ; 

 and eighteen miles and a half of drains, some parts of 

 which were thirteen feet deep, but the medium depth 

 of which was from five to seven feet, had, in 1820, ren- 

 dered between five and six hundred acres of land 

 most valuable, which had been before of little value. 



The drainage or drying up of lakes or ponds comes 

 occasionally within the practice of the drainer, espe- 

 cially in countries with an irregular surface. There 

 are, perhaps, few natural lakes indeed, the surface of 

 the water of which might not be very considerably 

 lowered, by deepening their natural outlets, the conse- 

 quence of which would be, in many cases, a very con- 

 siderable accession of generally rich land round their 

 margins, a better drainage for the surrounding country, 

 and an improved climate. Much, it is said, might be 

 done in this way in Ireland ; but there can oe no 

 doubt that in every country in the world a great deal 

 might be done. In flat countries nearly on a level 

 with the sea, like Holland and parts of the counties 

 of Cambridge and Huntingdon, the water will in gene- 

 ral require to be raised by machinery ; but in by far 

 the greater number of cases, deepening the natural 

 outlet will be found amply sufficient. 



Bar Loch, in the county of Renfrew, was reduced 

 in size by drainage and embanking, in 1814, at an 

 expense of nearly 10,000, which has since re- 

 turned 13 per cent, per annum ; 280 acres have been 

 laid dry, upwards of 200 of which have been since 

 under crop. A very interesting account of this drain- 

 age will be found in the Highland Society's Transac- 

 tion!, vol. vii. p. 375. 



The different sorts of drains in use may be classed in two di- 

 visions ; drains of conveyance alone, and drains of conveyance 

 and collection jointly. In the former, all that is necessary is a 

 channel or passage for the water, of sufficient dimensions, 

 which may be formed by pipes of different kinds, arched 

 or barrel drains, and box or walled drains. The construction 

 of the latter requires not only an opening for conveying 

 the water, but a superincumbent or surrounding stra- 

 tum, of sufficient porosity to permit and induce all latent water 

 to hnd its way to the channel of conveyance. The most 

 complete drain of conveyance is a large p;pe of metal, masonry, 

 or brick-work, and the most complete collecting drain, one 

 formed of a channel built on the sides, and covered with flat 

 stones, with a superstratum of round stones or splinters, di- 

 minishing to the size of gravel as they rise to the surface, and 

 there covered with the common soil. As the best constructions, 

 however, are not always practicable, the following are a few 

 of the leading sorts adapted for different situations. 



For drains of conveyance, there are the walled or box drain, 

 the barrel drain, the walled or the triangular drain, and arched 

 drain. 



Drain! of collection are formed of stone, brick, gravel, cin- 

 ders, wood, spray, straw, turf, and earth alone. 



The boxed and rubble drain may be used either as a 

 drain of conveyance or collection. The common rubble drain 

 i i formed of rough land-stones of any sort, broken so as not 

 t . exceed two or three inches in diameter. No good drainer 

 uses stones six or eight inches in diameter in any part of a rub- 

 ble drain, least of all at the bottom. The point kept in view 

 is to use such small -tones at the bottom as may allow the 

 water a great many channels ; so that, if a few should become 

 impermeable, there should be many others remaining. The 

 nearer the bottom of a drain of this kind approaches to the 

 character of a natural bed of gravel, the more certain will be 

 the free passage of the water. Gravel or ashes should be laid 

 on the top of the stones, on these a thin layer of straw or haulm 

 of any kind, and the remainder filled up with the surface soil. 



The brick drain is formed in a great variety of ways, either 

 with common bricks and bats in imitation of the boxed and 

 rubble, or rubble drain ; or with brick* made on purpose, of 

 which there is great variety. Draining tiK-s, to be used with 

 effect as collecting drains, should generally be covered a foot 

 in depth or more with stones or gravel. j';,,t if the land to be 

 drained be in grass, laying the sod over the tile is sufficient : 

 if the laud be not in grass, and be loose in textore, a little 

 straw may be profitably laid over the tile, to prevent the soil 

 from running in. The pantile U the best for general purposes, 

 but ought not to have holes at top ; but sometimes such holes 

 are made. In very loose soils, plain tiles are wanted to plan- 

 the draining tiles on ; in other soils, old broken pieces of plain 

 tiles are sufficient for the ends to rest on. Sometimes, even at 

 depths of six feet, these tiles, though of five inches in the 

 ek'ar, will be entirely blocked up by tiie tibroue roots of trees, 

 I.. 



especially of the black poplar. A variety of this tile, of a more 

 ample capacity, has lately been brought into use in Lincoln, 

 shire. The best draining tiles in England are manufactured at 

 the Staffordshire potteries. 



The gravel or cinder drain is seldom made deep, though, L. 

 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. 



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

 durable construction consists of poles or young fir-trees strip, 

 ped of their branches, and laid in the bottom of the drain 

 lengthways. They are then covered with the branches and 

 spray. Another furm is that of filling the drain with faggot- 

 wood, with some straw over. A variety of this mode is formed 

 by first setting in cross stakes to prevent 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 brushwood 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 brushwood into lengths 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 preparation, and 

 cover them with spray, straw, or rushes, and finally the sur- 

 face soil. 



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 brushwood 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. 



The straw drain, when reeds, rushes, and bean straw are 

 used, is sometimes made like the spray drain, by pressing the 

 loose material down, or forming a cable ; but in general the 

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

 a machine, and three or more of these laid in the bottom of a 

 triangular drain, with or without the protection of three 

 turves. Where some sorts of moss, as Sphagnum or Lycopo- 

 dium, can be got, these drains are of unknown durability. 

 Drains formed in this manner, 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 incumbent weight 

 of the soil and the casual traffic 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. 



The turf drain, may be made of any convenient depth, but it 

 must be at least the breadth of a turf at bottom. The drain 

 being dug put as if it were to be filled with stones or any ordi- 

 nary material ; the operator next, with a spade three inches 

 wide, digs a narrow channel along its centre, clearing it out 

 with the draining scoop; and over this the turves are laid with- 

 out any other preparation, or anything 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 pur- 

 poses that the farmer can expect to derive from drains con- 

 structed with more labour, and at a much greater expense. 

 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 water. 



The wedge or 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 required, but is contracted to a very narrow 

 bottom. The sods are then set in with the grass side downwards, 

 and pressed as far as they will go. As the figure of the drain 

 does not suffer them to go to the bottom, a cavity is left which 

 serves as a water course ; and the space above is filled with the 

 earth thrown out. The work is performed by meaus of three 

 spades of different sizes. The first may be a common spade of 

 moderate breadth, with which the surface clay may be taken 

 off to the depth of eight or ten inches, or not quite so much, if 

 the clay be very strong. The breadth of the drain, at top, 

 may be from a foot to fifteen inches; but it never should be 

 less than a foot, as it is an advantage that the sides should have 

 a considerable slope ; and the two tides should slope as equally 

 as possible. Another workman follows the first, with a spade 

 six inches broad at the top, and becoming narrower towards 

 the point, where it should not exceed four inches. The length 

 of the plate of this second spade should be fourteen inches, 

 and with it a foot or fourteen inches in depth can easily be 

 gained. A third workman, and he should be the most expert, 

 succeeds the second, and his spade should be four inches broad 

 at top, only two inches broad at the point, and fourteen or fif- 

 teen inches in length. With this spade a good workman can 

 take out at least fifteen inches of clay. A sort of hoe or scoop, 

 made of a plate of iron, formed nearly into the shape of a half 

 'cylinder of two inches diameter, and a foot or fourteen inches 

 long, and fastened, at an acute angle of perhaps 70, to R 

 long wooden handle, is now employed to scrape out the hot- 

 2 9 



