DRAINING.

To drain land means simply to make land dry. This definition is satisfactory in regard to the ancient art of draining, the object of which was to render land which was wetted by springs, or had become marshy by stagnant water, or subjected to the periodical overflowings of rivers, sufficiently dry to permit the exercise of arable culture. It is not so applicable to the modern practice of draining. Draining is now practised on land that is apparently dry, as well as on really w et land. Land that contains a superabundance of water produces plants of a peculiar nature, such as rushes, flags, sprots, and many others; and obstructs the operations of arable culture. The very existence of such plants is sufficiently indicative of the wet state of land. But land that contains no such superabundance of water as to obstruct its arable culture, but which, by its inherent wetness, may nevertheless prevent the luxuriant growth of the cereal grains and the cultivated grasses, requires draining as much as wet land, though w etness is not so apparent in it as in the other. The deficiency of the crop on apparently dry lands is naturally attributed to unskilful husbandry, till experience proves that no management, however skilful, can counteract the baneful influence of concealed stagnant water. Observation teaches us that stagnant water, whether on the surface or immediately under the surface of land, injures all the useful classes of plants. How the injury arises is not very clear; perhaps by obstructing perspiration and intro-susception, and thus diseasing their roots; or, what is more probable, it prevents their food from being presented in a nutritious state, by checking the chemical decomposition of the substances which supply the food of plants. Whether the true cause of the bad effects of stagnant water on the vegetation of useful plants will ever be discovered, the future progress of vegeto-physiological science can alone determine. In the mean time, experience assures us that draining will remove these bad effects.

It thus appears there are two species of draining; the one draws off the larger bodies of water which are collected from the discharge of springs in isolated spots, and the other absorbs the superabundance of water from and under the surface of the land. The first is called underdraining, because it intercepts the passage of the water from springs at some distance under ground. The second makes channels for .conveying away the water which falls on the surface of the ground, and is therefore called surface-draining. Surface-draining is again divided into two kinds; the one consists only in making small open channels and furrows immediately on the surface of the ground; the other is effected by means of small drains constructed at a short distance under the surface of the ground, in order to collect the water which would otherwise remain on a retentive subsoil at the bottom of the plough furrow. This latter kind derives its name from the particular construction of the drain.

The theory on which these different kinds of draining are founded is sufficiently explicit. Where the upper surface of land is at all permeable to water, and where it rests on beds of matter of different depths, of various lengths and breadths, each possessing a consistency of retentiveness or permeability, the water produced from rain, snow, or dew, in its progress along the porous bed, will be interrupted and retained by the retentive beds, and will accumulate in them in larger or smaller quantities, according as they present a basin shape, over the edge of which it will burst through the upper surface in the form of springs. Hence the necessity of under-draining to draw off the water contained in the basin-shaped curves of the retentive layers. Where the upper surface is permeable, and the subsoil immediately under it retentive, water will accumulate on the subsoil, to the injury of plants growing on the surface soil. Hence the origin of surface-draining, by laying land in ridges, and forming small open channels, along which the water percolating through the surface soil may have a free passage. Where the subsoil is so porous as to permit the water to percolate through it beyond the reach of the plough, these open surface gutters will have no effect in removing the superabundant water. Hence the second class of surface drains must then be constructed to absorb it. Where the surface soil and the subsoil are both permeable, they will hold water only by capillary attraction; and what is not so retained will sink down into the inferior permeable beds by its gravity. Hence in such land draining is unnecessary. Of these excessive supplies of water, that from springs is most injurious to the vegetation of useful plants, as being colder, and generally more permanent in their operation. Capillary attraction will retain as much water in the surface soil as vegetation requires, excepting under the extraordinary occurrence of excessive drought. Hence the abstraction of water by draining is quite independent of its supply as a manure, as a meliorator of the soil, as a menstruum for food, or as a regulator of temperature to plants.

These statements prove the necessity of a knowledge of geology for a perfect understanding of the principles of draining; and fortunately practice in this department of rural economy is not at variance with scientific principle. On the contrary, he who is best acquainted with geology and the principles of hydraulics, will constitute the most scientific drainer. But such a character cannot yet be easily acquired by any man; for that department of geology, the knowledge of which is most applicable to the art of draining, is the most difficult to be understood, and has hitherto been the least explored. Most of the arable soil is contained within the tertiary and alluvial formations of rocks. The intricate relations of the newer beds, which compose the alluvial class of rocks, and which are the most intimately connected with arable culture and draining, present almost insurmountable obstacles to the thorough acquirement of the art of draining. They at least throw an uncertainty over its operations; and this uncertainty must continue till the relations of the alluvial rocks are discovered to be as fixed as those of the other classes. Perhaps this certainty is unattainable; because it maybe that the newer members of the alluvia strata do not bear a strictly relative position to one another. But till this fact is ascertained one way or the other, draining must be conducted in a great measure in these alluvial deposites by trial. In undertakings on trial, error generally ensues, and unnecessary expense is often incurred. One very unfortunate circumstance, arising from the uncertainty attending draining, is the uselessness of the experience acquired in one set of operations, in guiding to a means of securing a more certain result in another. As uncertainty attends on the number and depth, and even direction, of the drains which are required to dry one field sufficiently, so a similar uncertainty prevails over the similar operations in the adjoining field. Every drainer will concur in the justness of these remarks. A deeper study by geologists in this [7:8:137]branch of geology would therefore confer everlasting obligations on the drainer; and would they also direct their particular attention to the connection between the upper surface of the earth’s crust, and the one immediately subjacent, that connection would perhaps be found to be intimate; or, at all events, the investigation would supply desirable materials for a correct nomenclature and classification of soils.

It does not appear that the ancients practised draining. The Egyptians, Indians, and Persians, and indeed the inhabitants of the tropical regions, rather practise the opposite though almost sister art in effect, namely, irrigation, on land which is beyond the influence of the great periodical overflowings of rivers. The Greeks had neglected draining; and indeed they did not attend much to agriculture. The Romans, on the other hand, skilful husbandmen in every department of agriculture, drained their lands with the greatest care and assiduity. Cato, their oldest writer on agriculture, enters so minutely into the importance of draining, as even to prescribe the dimensions and shapes of open and covered drains. The Romans had only been acquainted with the draining of springs, and the clearing away of surface water. For the former purpose the drains were left open at both ends, and the water from the springs was conveyed away by them out of the field, as particularly described by Columella. For taking away surface water they used open ditches in stiff soils, as Palladius informs us; and Cato directs that when the rain commences in autumn, all the servants should go out with sarcles, or other iron tools, open drains, turn the water into the channels, and take care of the corn fields, that it flow from them. It thus appears that the Romans were unacquainted with the deeper kind of surface-draining. In our own country draining has been practised for a long period. Ingulphus mentions that a chamberlain of William the Conqueror, Richard de Rulos, lord of Brunne and Deeping, drained a great extent of country, and embanked the river Wielland, which used to overflow the neighbouring county every year. It is more than probable that draining was practised in this country long before that period, as the Romans invariably introduced the arts of life into every country which they conquered. Fitzherbert’s Bohe of Husbandrie, which was published in 1534, during Henry VIIEs reign, contains minute directions for draining. But the greatest impulse which draining received in Britain was in the latter half of the last century; and that was given by a practical discovery of the seat of springs, by a farmer, Mr Elkington of Princethorp, in Warwickshire. Being an uneducated man, Elkington was not able to communicate his ideas to the public. Mr Johnstone, a drainer residing in Edinburgh, under the authority of the Board of Agriculture, published a full and satisfactory account of Elkington’s mode of draining wet land. Elkington was ignorant of geology, and coι⅛ld not therefore have acted on scientific principles. These principles Farcy, in his report, of the agriculture of Derbyshire, maintains that many contemporaries of Elkington understood better than he did. But whatever might have been Elkington’s personal qualifications, it cannot be denied that the mode of draining which he practised himself, and which he showed to many farmers and country gentlemen, produced a complete revolution in that art in this country. His principle was simple and strictly scientific, though he was probably not aware of its scientific character, or of the science which it involved; but it was undoubtedly its scientific nature which caused it to be attended with such success. He applied his principle chiefly to the draining of springs, which was simply to intercept the water by a drain at its source or spring; and the wetness in the land arising from that source will of course be removed. The cutting the drains deep is almost essential to the success of his system. The difficulty in the application of the principle consists in discovering the seat of the spring. A minute knowledge of the alluvial rocks would overcome this difficulty. In the present state of that knowledge, shrewdness must perform the part of science, assisted by trials in digging pits or cutting straight ditches through the beds of earth, in order to ascertain which of them contains the spring.

The drains which our forefathers made rested on the subsoil, immediately under the surface soil; and their depth under the surface depended on the depth of the upper soil. But as the depth of the arable soil, when it is of a different nature from the subsoil, is never very great, these drains were necessarily shallow. As experience, however, would soon teach men the impropriety of placing the stones in a drain within reach of the plough, few stones were placed in them, often not exceeding three, one on each side of the cut, and another above them, forming a sort of conduit. These conduits being near the surface, and of small areas, an additional quantity of water, or moles digging across them, placed such obstructions in them as to prevent entirely the flow of the water. They then became receptacles of water, and produced the mischief they were intended to remedy. Many of these drains are met with in the soil; and they appear to have been formed on the notion that a conduit to convey the stagnant jvater between the upper and subsoils was quite sufficient to render the soil permanently dry. The discovery of these trifling drains compels us to the belief of the fact, that the mode of draining practised by the Romans, and which without doubt they had introduced into this country, had been neglected or forgotten in the dark ages, previously to the revival of agriculture in Britain in the reign of Henry the Eighth.

Compared with the paltry method just described, the system of Elkington is super-excellent. No wonder that it produced at the time of its introduction a revolution in the art. It was as much more effective than the old system in changing the quality of the land, as blood-letting with a lancet from a vein affects the general constitution in a greater degree than the topical application of leeches. Elkington’s discovery also created discussion, which terminated in the permanent establishment of the present method of draining practised in this country. This method is a modification of that of Elkington; and it is an improvement, in as far as it effectually drains a species of wetness in land, for which his method is perhaps not so suitable. It is fully granted, that to drain bursts of water and marshy ground, it is necessary to cut off the springs which supply them with water; and that whatever depth of drain or strength of materials are required to effect these purposes, they ought to be executed. In this manner many extensive properties have been drained, at great expense it is true, but so effectually, that the increased income derived from the improved quality of the soil, and the more rapid growth of the trees, will continue as a permanent fund, from which the expense of the improvements will be amply repaid. Granting these advantages, with which, however, it is not intended to intermeddle, it is nevertheless maintained by many that the portion of land which is wetted by water springing from below, bears a very small proportion to that which is in a wet state from the retention of rain water on an impervious subsoil. A great extent of land may be wetted by the bursting out of a spring of water; and the obvious mode of drying that land is to remove the spring; but will the same mode of draining, dry land which is wetted to a great extent by rain water being retained in the surface soil like water in a sponge, in consequence of a retentive subsoil? Obviously not. A drain in a retentive subsoil cannot draw water[7:8:138] from a distance. A number of drains should therefore be made, all to co-operate by their absorbing power, in order to remove the water from the retentive subsoil; and as drains cannot draw water from a distance in a retentive subsoil, so in such a subsoil they need not be made deeper than to contain a sufficient quantity of materials to ensure their durability. This method of draining may be as expensive or more expensive than the system of draining springs; but whatever may be its expense, the increased produce and the improved quality of the subsequent crops will soon repay it. The theory on which this method is founded is also purely scientific. In the natural circumstances of the upper and subsoils, varying from light dry loam resting on beds of sand and gravel, to a thin steril crust, incumbent on impervious clay, the drainage must be various. In the former no water springs from below; and what falls upon the surface is immediately absorbed and carried down beyond the reach of vegetation. In the latter case, water, whether springing from below or falling on the surface in the shape of rain, must, where there is a declivity, run slowly off over the surface, however great the distance; or, in the event of a level surface, must remain stagnant till evaporated by the sun. On such a subsoil, a sufficient depth of active soil cannot be long maintained; for even if enriched with lime and manure, it will bear scanty crops; and if laid out for pasture, it will in a few years revert to its natural state, aiļd produce only coarse herbage. Some soils rest on subsoils partially permeable by water. Such, in dry seasons, with judicious management, produce good crops; but in rainy seasons the crops are thin and the grain inferior in quality. When soil is immediately incumbent on open rock, such as the trap rocks, which contain many fissures, the land is uniformly fertile. Thus carefully copying the operations of nature, if drains were made in retentive subsoils, so as to give water frequent opportunities of escape, the soil would then become fertile, like the soil which rests on the open rock. Hence the drains are made straight and parallel to one another, and as near to each other as is necessary for the effectual drying of the land. These parallel drains are placed down the inclination, instead of across the land.

Strong objections are urged against this system of surface-draining by those who are strenuous advocates of Elkington’s mode of cutting deep drains across the face of inclined ground. They maintain that fewer of these cross drains will dry the land than those which run straight down the inclined ground, and that these small drains will only serve a temporary purpose, and will have to be renewed at no great distance of time, at a greater cost than the making of cross drains. Such objections to the parallel straight drains are not so strong as they appear. It might be supposed, indeed, at first sight, that a drain passing across a piece of inclined ground will more readily intercept the descent of water than drains passing down in a direction parallel to the course of the water. But the fact is, in all pieces of ground which lie at an inclination, there is a double inclination, the one down the face of the inclination, which is always the greatest, and the other across its face. Water running down a double inclination will of course take the direction of the diagonal, in the exact proportion the angles of inclination bear to one another, provided the substance of the subsoil were homogeneous. As it is very improbable that the subsoil should be homogeneous, there is a risk of cutting the cross drains parallel to the course of the water, in which case they would not intercept any of it; whereas numerous drains cut parallel to the direction of the ridges on the inclined ground, would certainly intercept the water in its diagonal and devious course. Should the adoption of small drains cause them to be superficially constructed, this defect would be a strong objection against the whole system; but substantial drains are as necessary in this as in the other system. Drains which are to contain broken stones, and no other material will answer the purpose in a retentive but spongy subsoil, should not be less than thirty inches in depth; one foot for the passage of the plough over the stones, and eighteen inches of small stones. This is the least size the drains should be, and of this size they will endure for generations. In this mode of draining it is proposed to make the drains three feet deep.

Having explained the rationale of different modes of draining, it will be necessary to give a minute detail of the mode of forming the different kinds of drains.

It is scarcely necessary to state that all drains must be cut in a direction to permit the water in them to run down hill. No drain should be made more level than an inclination in the bottom of one foot in twenty-five yards. With this fall water will easily gravitate in a drain. Drains formed for the purpose of drying springs which are not in the immediate vicinity of marshy ground, should be four feet in depth at the least. A reservation is made in case of marshy ground, for it is probable that its vicinity will not afford a fall of four feet. All drains of four feet in depth should be filled with small stones gathered from the fields, or stones from the quarry broken small for the purpose; and such drains should always be built with a conduit of dry masonry, of a size in the opening proportionate to the quantity of water which it is supposed will run through them; and the size of this conduit will of course regulate the breadth of the bottom of the drain to be cut out. In all cases of conduits they should be built on a bottom floored on stones; for in many kinds of clay which have a mixture of sand (and in all drainable clays such a mixture does exist), the water, if considerable, will wear away the clay from under the conduit, and cause sinkings in the drain. The small stones should be carefully packed around the conduit with the hand till it be covered, and the remainder thrown in from the side of the drain by the hand, to within eighteen or fifteen inches of the surface of the ground. When the filling is completed, the stones should be neatly levelled; the filling should commence immediately after the cutting is finished, which should be executed in small portions at a time. The stones should be covered over with any material which will prevent the loose earth trickling down through them into the drain, such as straw, which is perhaps too valuable an article for this purpose, turf with the grass side downwards, or quicken well shaken of its earth gathered from the fallow fields. The levelling of the earth which has been cast out should be executed as soon after the filling of the stones as possible, and it should be carefully and not slovenly performed; as a ridge of earth, however small, placed across a piece of inclined ground, and which cannot afterwards be removed till the field is ploughed up again, will intercept the water in its descent down the furrows, and there cause that moisture in the ground which the draining was intended to remove. An easy method of levelling the earth is to put some of it in the first place with the spade over the covering of the stones, and then to pass the plough and turn the earth over into the drain in the same direction, returning the plough empty. This operation may be repeated twice or thrice, according to the quantity of earth to be levelled, and then a space of the adjoining ground may be ploughed with that thrown out, in the manner of a common ridge, till the whole is flat. It is almost always recommended to fill drains from their upper end towards the mouth. This may be a desirable arrangement when the drain is necessarily very level, in order to preserve the fall, but never [7:8:139]otherwise; for the risk which is incurred should wet weather set in, by the falling in of the sides, while waiting for perhaps a great length of cutting, would more than counteract any advantage of preserving a minute level. These general observations on the cutting and filling and covering of drains apply to every species of drain. Other general observations are, that main drains, into which the lateral drains empty themselves, should be larger than the lateral ones. Main drains should be cut in the nearest and most convenient hollows for the outlet of water from the fields. All lateral drains should enter the main drain, or other lateral drains, with an acute angle of confluence, to expedite the water in its course. The mouths of main drains should be left open, strongly built, and defended with wooden or iron bars, to prevent the ingress of the larger class of vermin, such as badgers, foxes, and polecats.

Where square stones cannot be easily procured for the building of conduits, and where flat stones are more plentiful, they should be used in coupling, that is, one should be laid flat on the bottom of the drain, and other two set up on it, meeting at the top, the three forming an isosceles triangle. Small stones should then be packed carefully with the hand along the side and over the apex of the triangle. This coupled drain is perhaps not so strong as a built conduit, but it may be made very durable if the stones are of compact structure, and it is less expensive, as it requires a narrower cut than the conduit.

Drains from three and a half to two and half feet deep should be wholly filled with small stones. They are termed rubDle drains. They need not exceed the breadth of a garden spade at the bottom. The small stones with which they are filled should not exceed the size of the fist, and they should be thrown in by the hand from the side of the drain; not carelessly against the sides and on the bottom of the drain, but rolled down, as it were, the inclined face of the stones already filled in. In this manner they will arrive easily at the bottom, and find their own position. When rubble drains are formed in hazel loams, they become the favourite resort of earthworms in search of fresh and unexhausted soil. Moles soon follow them, and these may cause damage to the drains if precautionary measures be not adopted. The pressing of the smallest stones by the foot into the bottom of the drain, to form a sort of causeway upon which the other stones arc placed, is an insuperable obstacle to moles running under it, and heaving the earth up into the drain.

It has always been recommended to build conduits in quicksands; but the circumstance most deserving notice in the drainage of these troublesome things is the laying the bottom of the drain with flat stones, and building up its sides with a sort of masonry, in which pieces of turf should act as mortar, to prevent the sand running into the middle of the drain. Instead χ>f leaving the conduit open, it should be filled up with small stones carefully packed in with the hand, because this construction is the strongest for resisting the lateral pressure of the quicksand.

In regard to the comparative advantages of a conduit and rubble drain, where no necessity exists of making the drain so deep as the stones at the bottom would be pressed into the earth by the weight of those above them, and this injurious effect will not be produced at a less depth than three and a half feet, no better materials can be employed to fill drains than hard round stones not exceeding the size of a goose’s cgg. It will be quite unnecessary to be at the expense of conduits and couples in all those shallow drains formed in retentive subsoils not containing springs. Water in the quantity generally found in drains, percolates through rubble stones with less injury to the drains themselves than in conduits; because, after a tract of wet weather, when the water in all drains is more or less turbid, according to. the soil through which it passes, the rubble drain retards its current throughout its whole course, and causes it to deposite what portion of earth may be mechanically suspended in it, in a gradual manner; whereas the rather rapid current in a conduit will deposite its earth in quantities in every eddy which it forms, and in the course of time banks of earth will be formed in the conduit at different places, so as to affect the depth of the drain above those deposites.

Tiles made on purpose for drains are now very frequently used instead of stones. They are sometimes made in the shape of long truncated cones which fit into one another, but more commonly in semicircular pieces placed upon flat tiles. Where stones can be procured for the gathering, or quarried near at hand, and a sufficient quantity can be obtained of them, they are in every case superior to tiles for draining. Tiles may be beneficially used in conjunction with stones when the latter are carefully packed around, and of a sufficient depth above the former. They may also be used in clay soils, if well packed in a mass of peat moss. Clay soils seldom contain stones, but are often associated with peat. Tilcs at present (1833) are for the most part used in furroiv-draining, that is, in drains cut in any furrow between the ridges. These drains arc generally made twenty inches in depth, one foot wide at the top, and two or three inches at the bottom. Sometimes small broken stones to the height of ten inches are used in these drains instead of tiles. With whatever materials they are filled, such a size of drains is objectionable. If intended to drain springs, they are incompetent to reach their source; if surface water arising from rain lodging on an impervious subsoil, the paucity of materials in them deprives them of utility and durability. Such a system can only serve a temporary purpose; and in a permanent improvement such a motive should always be proscribed. Draining insufficiently performed is nearly as bad as leaving it undone. Its defects cannot frequently be discovered till a great loss has been sustained.

Another method of draining has lately been introduced, and is termed plug-draining. It is exclusively confined to the draining of tenacious clay, and chiefly practised on pasture land. It consists of removing the turf with a common spade twelve inches in width and six inches in depth. The clay under the turf is removed with a narrow-shaped instrument called a grafting iron, on the side of which is raised a cutting bit six inches long, to the depth of eighteen inches. The drain is made two feet deep, one foot in breadth at the top, and one inch and three quarters at the bottom. Plugs of wood to fit the bottom of the drain, one and three quarters of an inch wide at bottom, four inches at the top, and six inches in height, and of any length, perhaps a foot, are then placed in the bottom. The clay last taken out of the drain is returned into it and rammed hard down, until the whole clay thrown out is replaced in a solid mass into the drain. Upon the clay the grass turf is replaced in its original position. The plugs are then withdrawn from below the clay to within eight inches of their length, by means of a lever acting upon it with a chain attached to the end of the plugs. Three or four of these plugs are united together by iron slips, which permit them to have as much play as to accommodate themselves to any curvature or inequality in the cutting of the drain. Expedients for draining the surface of grass lands have frequently been attempted; such as turning over a turf slice with the plough, paring the earth off the bottom of the turf slice with a spade, and replacing it. The drain thus made is like a large mole gallery, and hence it is called mole-draining. But this and the plug-draining, and all other expedients of the like kind, are [7:8:140]but temporary shifts. They all originate in a false notion of economy. The advantages of draining can only be obtained when it is effectually executed, and it cannot be so executed without a considerable expense. Its operations being beyond the reach of daily observation, is a strong reason for executing it effectually. To be obliged to rectify the errors of draining is a serious evil, and will always cost more than a judicious primary outlay.

The minor adjuncts connected with Elkington’s mode of draining springs should not be overlooked. They consist of boring with the auger, and sinking pits. Where tenacious beds of clay of moderate thickness forming retentive subsoils rest on gravel or sand, or open rock, holes bored through them with the auger when their depth is considerable, or pits sunk through them when they are less so, may effect a very considerable saving of expense. There is obviously no use of cutting a great length of a main drain, merely as a conveyance for water, when a hole or a pit opened on the spot would effect a similar purpose. In many cases, rich marshy land, and land-locked lakes, cannot be drained in any other way. A correct knowledge of geology is essentially necessary in this department of draining, in order to arrive at the desirable result with the least trouble.

These various modes of draining, which have been but imperfectly described, are executed in what may be termed different styles. Elkington’s mode presents a ramified or dendritic appearance. The main drains occupy the lowest parts, or the hollows of fields. From them the lateral drains branch out in various lengths in a sloping direction along the inclined face of the ground. Where springs abound at the foot of mountain ridges, and where the substratum consists of beds of sand, however thin, in-terlayed with thick beds of impervious clay, and where the water evidently rises from below, this is the most beneficial system of draining which can be followed. The upper soil on such a substratum is generally a clay loam, unprofitable when wet, but extremely grateful when dried. With deep ploughing, plentiful liming, and liberal manuring, after drainage, such land will continue for ages to produce wheat, clover, beans, and Swedish turnips, in abundance. The expense of this method of draining is considerable by the rood, though not by the acre. It will be more than a shilling per rood of six yards; but not exceeding L.3 or L.4 per imperial acre. These clay loams almost always rest on inferior kinds of clay, of various qualities and colours. They rest on retentive subsoils, generally occupy large flats, large detached patches, knolls, and often run in bands across part of the country. In hollow portions of ground, mossy soils of little depth rest on these clays. In examining the structure of the subsoil on which these clay loams rest, it is probable they have been deposited when the retiring waters were nearly in a quiescent state. Though the different kinds of clay, often exhibiting different colours, are not arranged in horizontal or parallel beds, they appear in undulating beds of different lengths, and of contemporaneous formation, and these are frequently divided by thin beds of sand. These undulations act as basins to intercept and collect the water which permeates gradually through the detached beds of sand. This permeant properly permits them to contain large quantities of water, and hence this class of soil is very wet, and difficult to manage before they are drained. Very frequently a thicker bed of sand than the rest divides the mixed clayey subsoil from clay of a different and generally more homogeneous structure below it; and in cases where this homogeneous clay is not more than six feet below the surface, and it is often less, it forms an excellent flooring for a main drain.

Another style of draining has lately assuméd the appellation of the frequent-drain. It consists of cutting parallel rows of drains down the face of inclined ground, which terminate in a main drain in the lowest part of the field. Contrary to the mode of draining just mentioned, this will cost little per rood, and much per acre. The expense in the hardest clay subsoil will not exceed tenpence per rood of six yards; but from the number of drains required, it will cost in such a subsoil nine or ten pounds per imperial acre. The cost of course will be in proportion to the obduracy of the material to be operated upon. In clayey subsoils generally of a reddish hue, containing small round and angular stones, frequently round masses of slaty sandstone, sometimes water-worn boulders of the older formations, and isolated veins of sand, this species of draining is admirably adapted, provided the drains are made of a sufficient depth to contain eighteen inches of small stones. This subsoil often continues of the same structure to a great depth, and it is very retentive of water, which has its origin in it chiefly from above in the shape of rain and snow. Deep draining is quite inapplicable to this subsoil. From the very structure of the subsoil, it is clear that digging the drains beyond a certain depth will confer no advantage. Water permeates such a subsoil only through the sand which it contains; and as that exists in an isolated state, it is not in the power of any drain to attract moisture from a distance. Dark hazel-coloured loams and black mould generally rest on these subsoils. These soils, when drained, form good turnip land, are sound for the rearing and feeding of live stock, raise barley of fine quality, and will carry good winter and spring wheat, when clay enters into their composition. In deep loams, where the influence of moisture is remote, draining, at least deep draining, is unnecessary. It is more necessary in thin loams, as the proximate relation of the subsoil to them in regard to a state of wetness has a direct influence on the productive powers of the soil.

Eurrow-draining consists of cutting a drain in every furrow between the ridges, and these drains will be crooked or straight as the furrows are so: the drains terminate in a main drain at the lowest part of the field. The only instance where furrow-draining can be safely recommended is in pure clays, where the soil from time immemorial has been formed into broad, high, crooked ridges, the furrows of which cannot with propriety be changed in ploughing the land, as may be done with most other soils. Many of these furrows contain surface water during a great part of the year, which frequently destroys the crops half way up the sides of the ridges, the general declivity of the surface of the land being unable to convey away the water without the assistance of drains. But instead of making these furrow-drains two or three inches wide at the bottom, as is usually done, they should never be less than the breadth of a common spade, and filled eighteen inches high with small stones or gravel, or tiles with peat moss, and the remainder to the top with porous earth. Pure clays, which extend to some depth, and which have the upper and subsoils composed of homogeneous clay, if judiciously managed, require no draining at all, not because they are not wet soils (on the contrary they are very wet soils), but because water cannot permeate through them, except as far as the plough reaches. Such soils may be effectually dried by deep ploughing, and keeping the furrows always clear with the spade. To keep such a soil dry, a practice might be beneficially taken from Irish agriculture. It is called double shovelling. This is done after the land is water-furrowed. A cutting plough drawn by two horses, one before the other, is passed along the furrow. The plough goes and returns close to the sides of the ridges, and at six inches deep, thus furnishing fresh mould, and preserving[7:8:141] a narrow furrow, the shovelling with the shovel or spade being completed from its depth instead of its width; and if the mould be thus ploughed in dry weather, it can be shovelled even after receiving rain. In retentive soils these furrows are absolutely necessary; and by the foregoing method, the extra covering for the ridge, by which some harrowing is saved after the sowing of the seed, is produced with nearly as little waste of ground as by the common water-furrow drawn by the plough. All flat clay deposites, or what are called Carses in Scotland, are composed of this kind of soil, and many detached fields on the sides of winding rivers may be found of a similar character. They cover a very inconsiderable portion of the face of the country, though in productive powers they stand in the first rank of soils.

Sandy soils resting on sand require no draining. They are found occupying extensive flats on the estuaries of large rivers. All soils resting on a subsoil of gravel are naturally dry. Drought alone injures them. It is remarkable that all soils which rest on gravel are a light loam, of a light hazel-brown colour, whether they have a siliceous or alluminous basis. These constitute the true turnip soils, and are to be found on the banks and haughs of straight-running rivers, rapid streams, and fresh-water lakes.

A thorough knowledge of the various modes of draining is not alone sufficient to constitute a good drainer; he should know the principles as well as the practice of his art. The difficulty is not so great in constructing a drain, as in knowing where it should be made. A true knowledge of whether the wetness in land arises from springs or stagnant water under the surface of the soil, can alone teach a man where to open up the ground. Every manager of land unfortunately thinks he possesses that knowledge, and the consequence has frequently happened that small drains have been opened where only deep ones should have been, and much money expended in making deep drains where smaller ones would have answered the purpose. But the former error is greater than the latter. In neither case, however, has the money expended been thrown away. A certain degree of success has attended every attempt at draining; and this favourable result, perhaps, more than any other circumstance, has beguiled many into the belief that they are accomplished drainers; for no one, however incapable he might be of directing the operation aright, would even make the attempt to drain land until he had actually experienced an obvious injury arising from wet land. It must be confessed that many improvements effected by draining have been purchased at a greater cost than was necessary to accomplish the end. Many attempts have been made at draining land by men who did not know how to accomplish it to the best advantage either to themselves or the land. -The outlay of their money has therefore been ill directed. W ere the evil effects of ignorance confined to the squandering of a little money, they might be counteracted by superior management in the other operations of the farm. But, unfortunately, the sinking of valuable capital in injudicious draining, deprives the farmer of the means of pursuing other improvements, and prevents his reaping all the advantages derivable from draining itself. Thus crippled in his resources, he cannot put and maintain his farm in the highest condition; for such is the generous character of our farmers, as promoters of improvement, that they cannot be accused of the desire of hoarding up riches through the love of gain, so long as they can improve the condition of their farms in any way, even though they themselves may not ultimately reap the advantages arising from those improvements. Were draining an operation which could be executed at little cost and trouble, it would be of little importance to urge its accomplishment in the most effectual way; but as it is an expensive operation, when conducted even in the most economical manner, much thought is requisite before attempting to break up the ground to a great extent. A knowledge of the structure of the upper portion of the earth’s crust is absolutely necessary to direct our thoughts aright on this subject. That knowledge may even now be partially acquired by any farmer. Let him therefore, in the first place, contemplate the facts it unfolds to his view, and endeavour through them to acquire that wisdom which will direct him to expend his money in draining with prudence as well as skill. It will assist him much in ascertaining what are the kinds of soil which require deep draining, and what kinds may be treated equally well under a different management. Inattention to this distinction has given rise to the inordinate application of a general principle, which, as a general principle, but subject to great and necessary limitations, must receive the approbation of every man who knows and feels the importance of this improvement in husbandry.

Much has already been effected in Great Britain, but much yet remains to be done, by draining. A vast extent of the arable land of England and Scotland, and we may more especially include Ireland, generally esteemed dry, is yet so far injured by the tardy and imperfect escape of the water, especially in winter, and during long periods of wet weather in summer, that the working of it is often difficult and precarious, and its fertility much below what would uniformly exist under a thorough dryness. A system of drainage, therefore, generally applicable, and effecting complete and uniform dryness, is of the utmost importance to the agricultural interest, and through them to every other interest in the country.

The advantages arising from draining land are both numerous and various. Manures and stimulants can never impart their peculiar benefits to any soil which rests continually on a wet bottom ;—the operations of husbandry can never be accomplished in due season ;—and the produce is never abundant or of good quality in such circumstances. Draining removes all these evils. It is truly an operation, as Pliny terms it, of the highest utility,— Hu-midiorem agrum fossis concidi atque siccari, utilissimum est —it is not only the meliorator, but the maker of soil. Let no one despair of his soil, however forbidding; let him really drain it, and the results will encourage him.

The general improvement of the soil by draining would lower the value of high-rented land; but it would greatly increase the aggregate rental of the kingdom. It would diminish the general cost of produce, thereby affording cheaper provisions to the consumer. Both landlord and tenant would have greater returns from the land; and these returns being permanent, the landlord ought to bear the greatest share of the expense. Increased production would create a demand for labour, and the labourers of all professions would be enabled to live more comfortably. From this only true mode of cheapening labour, the British manufacturer would be aided in his competition with foreign labour ;—the general revenue of the country would increase ;—the salubrity of the climate, and the general beauty of the country, would be greatly promoted. There is no subject, therefore, more worthy the attention of the landed interest, than the encouragement of thorough drainage, and, as a necessary and beneficial consequence of draining, the deep working of the soil. (κ. κ. κ.) [7:8:142]