Irrigation necessary to beneficial irrigation. It is folly to incur the expense of forming the most perfect water meadow without an ample supply of water to fill the channels to overflowing. The supply of the water must be on a higher level than the ground to be irrigated. The fall need not be more than is necessary for a pretty rapid current of water, which, in ordinary cases, may be 10 inches or 1 foot, for 100 or 200 yards, and about 2 feet for 300 yards. The water, if possible, should be taken as far above the meadows as to have a sufficient fall without damming up the river. When this plan is impracticable, but only when impracticable, a dam should be thrown across the stream at such a distance above the meadow as to secure not only a sufficient fall, but to protect the fields on both sides from inundation, whether the fields belong to different proprietors or not. For, in regard to dams across small streams which form the boundaries of farms or estates, it may not be irrelevant to mention that alterations have frequently arisen from supposed damages arising from inundations or infringements on the rights of waters. In every case, therefore, of constructing a dam for irrigation, it will be wise to avoid the chance of disputes, by acquiring, in the first place, the right for such an erection by purchase or otherwise. When a dam is inevitable, it should be constructed substantially. The first cost will be less than the repairing of a dam which has blown up from under or burst out at the sides. When water cannot be obtained under these prerequisites, conjoined to an ample supply, then the formation of water meadows at that place should be altogether relinquished. But should the requisite desiderata be available, the field to be converted into a water meadow should in the first place be thoroughly drained. The most perfect piece of workmanship as a water-meadow will be comparatively useless, unless the water which has passed through the soil to the subsoil find a free egress by drains. Without drains the water will inevitably stagnate on the subsoil, unless indeed the subsoil consists of very porous materials, such as chalk, sand, gravel, or fissured rock.

Besides the particulars enumerated, two essential rules in the formation of water-meadows should never be neglected, namely, that no part of them, however small, should be on a dead level; and that every drop of water, while irrigating, should be kept constantly in motion. These rules are founded on the very principle of irrigation which has been illustrated in the prelatory remarks. True inclined planes can be the only form of surface to which these rules will strictly apply; but although it may not be possible to stretch such planes along a great extent of surface, as ground is proverbially uneven, yet every portion of it which is watered directly from the main supply should be so exactly inclined. The spirit-level should be the rade- moom of the irrigator, the eye being deceptive in regard to the levelness of ground; and even with that indispensable instrument, the irrigator will find the formation of a complete water-meadow on an irregular surface no easy task. Superficial observers may see little difficulty in the operation; but the practical irrigator knows how nice a thing it is to adjust irregularities of ground to the constant and equable flow of water. So great is this difficulty that none but professional irrigators ought to attempt the formation of water-meadows, and they ought to be of established character and experience.

The first thing to be done for any water-meadow is to make the conductor or drain which brings the water from the river to the meadow. The size of the conductor depends entirely on the quantity of water which the meadow requires. Its bottom, at its junction with the river, should always be as low as the bottom of the river, in order to carry away as much mud as possible to the meadows. Its course should be as straight and as near an inclined plane as possible. The stuff taken out of the conductor should be employed in equalizing its banks, or filling up irregularities in the meadow. These general directions naturally lead to the examination of the particulars of which the different kinds of water meadows enumerated consist.

I. BED-WORK IRRIGATION.

This species of irrigation is eminently applicable to level ground, and under it, as the name implies, the ground is thrown into beds or ridges. After the conductor has been brought from the river to the meadow as directed, it should be led along the highest end or side of the meadow in an inclined plane; and should it terminate in the meadow, and not have to proceed farther on to another, its end should be made to taper when there are no feeders, or to terminate in a feeder. The tapered end will retard the motion of the water, and containing, of course, less water, the water will overflow the banks of the conductor. The main drain to carry off the water after it has irrigated the meadow should next be formed. It should be cut in the lowest part of the ground at the lower end or side of the meadow. Its dimensions should be capable of carrying off the whole water used, so quickly as to prevent the least stagnation, and discharge it into the river. The stuff taken out of it should be used to fill up irregularities in the meadow. In case the river takes a turn along the lower end or side of the meadow, the turn should be used as a main drain to carry off the water, and save the expense of cutting a drain. It may be imagined that as a portion of the water will be absorbed by the soil, the main drain need not be made so large as the conductor, merely to carry off the water that has been used; but in practice it will be found, that when the water is muddy, very little of it comparatively will enter the ground, because the sediment, acting as an impervious covering, prevents much of the water from descending into the ground. The next process is the forming of the ground intended for a water-meadow into beds or ridges. That portion of the ground which is to be watered by one conductor should be made into beds to suit the circumstances of that conductor; that is, instead of reducing all the beds over the meadow to one common level, they should be formed to suit the different swells in the ground, and should any of these swells be considerable, it will be necessary to give each side of them its respective conductor. The beds should run at or nearly at right angles to the line of the conductor. The breadth of the beds is regulated by the nature of the soil and the supply of water. Tenacious soils and subsoils, and a small supply of water, require narrow beds as thirty feet. Porous soils and a large supply of water may have beds of forty feet. The length of the beds is regulated by the supply of water and the fall from the conductor to the main drain. If the beds fall only in one direction longitudinally, their crowns should be made in the middle; but should they fall laterally as well as longitudinally, as is usually the case, then the crowns should be made towards the upper sides, more or less according to the lateral slope of the ground. The crowns should rise a foot above the adjoining furrows. The beds thus formed should slope in an inclined plane from the conductor to the main drain, that the water may flow equably over them. The beds are watered by what are called feeders, that is, by channels gradually tapering to the lower extremities, and their crowns cut down, wherever these are placed. The depth of the feeders depends on their width, and the width on their length. A bed two hundred yards in length requires a feeder of twenty inches in width at its junction with the conductor, and it should taper gradually to the extremity, which should be one foot in width. The taper retards the motion of the water, which constantly decreases Irrigation by overflow as it proceeds, whilst it continues to fill the feeder to the brim. The stuff which comes out of the feeders should be carefully and evenly laid along the sides of the beds. The water overflowing from the feeders down the sides of the beds is received into small drains formed in the furrows between the beds. These small drains discharge themselves into the main drain, and are in every respect the reverse of the feeders; that is, their tapering extremities lie up the slope, and their wide ends open into the main drain, to accelerate the motion of the departing water. The depth of the small drain at the junction is made about as deep as that of the main drain, and it gradually lessens towards the taper to six inches in tenacious, and to less in porous soils. The depth of the feeders is the same in relation to the conductor. The stuff obtained from the small drains is employed to fill up inequalities in the meadow. For the more equal distribution of the water over the surface of the beds from the conductor and feeders, small masses, such as stones, solid portions of earth or turf fastened with pins, are placed in them, in order to retard the momentum which the water may have acquired. These stops, as they are termed, are generally placed at regular intervals, or rather they should be left where any inequality of the current is observed. Heaps of stones answer very well for stops in the conductor, particularly immediately below the points of junction with the feeders. Solid portions of earth are usually left in the feeders, or tough pieces of turf fastened down with wooden pins; but care must be taken to keep the tops of the pins below the reach of weeds floating on the surface of the water. These stops, however, are nothing but expedients to rectify work imperfectly executed. It must be obvious that a perfectly formed water-meadow should require few or no stops. The small or main drains require no stops. The descent of the water in the feeders will no doubt necessarily increase in rapidity, but the inclination of the beds, and the tapering of the feeders, should be so adjusted as to counteract the increasing rapidity. At all events notches cut into the sides of the feeders to retard the velocity of the water, is much more objectionable than stops, although some writers recommend them; but where they have been observed, the spectator may depend on having seen an imperfect water-meadow.

The distribution of the water over the whole meadow is regulated by the sluice, which should be placed at the origin of every conductor. By means of these sluices any portion of the meadow that is desired can be watered, whilst the rest remains dry; and alternate watering must be adopted when there is a scarcity of water. Each sluice should be placed according to the elevation or depression of the ground which it supplies with water. All the sluices should be substantially built at first with stones and mortar; because a carelessly constructed sluice will permit the leakage of water at all times; and should the water from the leak be permitted to find its way into the meadow, that portion of it will stagnate and produce coarse grasses. In a well formed water-meadow it is as necessary to keep it perfectly dry at one time, as it is to place it under water at another. A small sluice placed in the side of the conductor opposite to the meadow, and at the upper end of it, will serve to drain away the leakage that may haply have escaped from the head sluice. The laying out of the beds, feeders, and small drains, constitutes the nice part of the formation of a water-meadow; it constitutes the test by which the skill of the irrigator is tried; and it is impossible to acquire the skill without practice.

To obtain a complete water-meadow, the ground will often require to be broken up and remodelled; for it is rare to find a piece of ground naturally possessing the requisite qualifications of a water-meadow. Such a remodelling will no doubt be attended with cost; but it should be considered that the first cost is the least; and remodelling the only way of obtaining the desired object of having a complete water-meadow which will continue for years to give satisfaction.

To effect a remodelling when the ground is in stubble, let it be ploughed up, harrowed, and cleaned as in a summer fallow; the levelling-box employed when required, the stuff from the conductors and main drains spread abroad, and the beds ploughed into shape. All these operations, as of the farm, can be performed at little expense, and they form the substantial foundation of the nicer operations of the spade, the barrow, and the level. The meadow should be ready by August for sowing with grass-seeds. The seeds best suited for a water-meadow are perennial rye-grass (Lotum perenne), sweet-scented vernal grass (Anthoxanthum odoratum), crested dog's tail grass (Cynosurus cristatus), meadow foxtail grass (Alopecurus pratensis), roughstalked meadow-grass (Poa trivialis), and fiorin (Agrostis stolonifera). The fiorin is the prevailing grass in all good water-meadows, and it makes a most delicious hay. It is best propagated by sowing the stems chopped into pieces like chaff. These grasses do not always produce a good crop the first year, but the rye-grass will assist to thicken the crop. Some writers, and particularly Mr Smith in his Essay on Irrigation, assert that it is of no importance what grasses are sown in water-meadows, as the most congenial kinds will in time spring up and banish all the others; but is it not better to supply the ground at once with the best grasses than wait for the extirpation of the worst? The method now described of forming a water-meadow is attended with one great disadvantage; the soft ground cannot be irrigated for two or three years after it is sown with grass-seeds. This disadvantage can only be avoided where the ground is covered with old turf which will bear to be lifted. On ground in that state a water-meadow may be most perfectly formed. Let the turf be taken off with the spade, and laid carefully aside for relaying. Let the stript ground then be neatly formed with the spade and barrow, into beds varying in breadth and shape, according to the nature of the soil, and the dip of the ground; the feeders from the conductor, and the small drains to the main drain being formed at the same time. Then let the turf be laid down again and beaten firm, when the meadow will be complete at once, and ready for irrigation. This is the most beautiful and most expeditious method of making a complete water-meadow where the ground is not naturally sufficiently level to begin with.

The water should be let on, and trial made of the work, whenever it is finished; and the motion of the water regulated by the introduction of a stop in the conductors and feeders, where a change in the motion of the current is observed, beginning at the upper end of the meadow. Should the work be finished as directed by August, a good crop of hay may be reaped in the succeeding summer. There are few pieces of land where the natural descent of the ground will not admit of the water being collected a second time, and applied to the irrigation of a second and lower meadow. In such a case the main drain of the watered meadow may form the conductor of the one to be watered, or a new conductor may be formed by a prolongation of the main drain; but either expedient is only advisable where water is scarce. Where it is plentiful, it is better to supply the second meadow directly from the river, or by a continuation of the first main conductor. In some instances it may be necessary to carry a conductor over a hollow piece of ground along an aqueduct made for the purpose, called a carry-bridge. Such an aqueduct may be made either of wood, cast-iron, or stone and mortar.

As a real example of a water-meadow, such as has been described, will illustrate the several particulars specified more accurately than any imaginative case, fig. 1 is a design of one belonging to Mr Loch of Rachan in Peeblesshire, and executed in 1823 by Mr George Stephens, drainer. II. CATCH WORK IRRIGATION.

MR BICKFORD'S IMPROVED DEVONSHIRE SYSTEM.

We have thought it right to give the details of Mr Bickford's system as the best illustration of the catch-work plan, while it has the advantage of being comparatively cheap in its first construction, and has met with the approval of eminent practical agriculturists, such as Mr Pusey, Mr Druce of Eynsham, and others, who have introduced it into other counties besides Devonshire with great success. Mr Bickford thus describes it:

After nearly twenty years' experience of this system of watering meadows in different situations, and under nearly every variety of circumstance, I may without presumption judge of its value; and being confirmed by the experience of my neighbours, whose opinions are entitled to respect, I venture to offer it for the consideration of others, believing that the use of this system would have the general effect of improving irrigated meadows in yearly value from 10s. to 20s. per acre. I am confirmed in this opinion by long experience, strengthened by the estimate made of it by a few agriculturists who happen to have had their attention drawn to it—persons well qualified to judge of such matters.

This system has the advantage over the common system of obviating the necessity for large and frequent level gutters; it has the effect of containing (and even causing) a smooth and uniform surface to the meadow, allowing of the operations of mowing and carting over the meadow without any sensible perception of the existence of the gutters used for irrigation; and also, that of accelerating the speed of the water over the land when "turned on," and the speedily draining the water from the surface when "turned off." In fact, it becomes an instrument in the hands of the irrigator, by means of which he can do with ease whatever his judgment determines ought to be done. It also obviates that waste of land occasioned by the usually large gutters. In fine, I profess to say that it is every way better than the old system: it can be done in half the time, and for less money.

Without further preface, I shall proceed with the details of the plan, and shall endeavour to make it quite intelligible. The chief features of the system consist in causing the ground intended to be irrigated to be covered with a net-work of small gutters, intersecting each other as nearly at right angles as circumstances will permit. These gutters are about 4 inches wide and 1 inch deep; they are cut with a "die," fixed in a sort of plough of simple construction, drawn generally by one horse. This net-work of gutters is fed at the highest level possible, or thought desirable, by a carriage gutter of sufficient size for the purpose, to be determined by the operator.

The system will be fully brought to view in the course of the description I shall give of the manner to be pursued in laying down the levels.

Let fig. 1 be a piece of meadow; look first where the water enters the meadow, or where it can be sent to enter. This is a matter of some importance, and should be considered well, in order to get the best supply of water, at the best place, and at the least expense. Let this be ascertained to be at A in figure 1. Then estimate roughly where it may be supposed the water will run; suppose along the dotted line 1...2. Then take the level (fig. 2), and proceed to mark a line across the meadow, according to the following rule. Set the feet Nos. 1 and 2 (fig. 2) level on the ground by means of the plumb-line 3; mark the place of No. 1; then advance the level by putting No. 1 in the place of No. 2, and finding a new place for No. 2 by means of the plumb; and so proceed until you have made a level line across the meadow, subject, however, to certain variations, which I shall show as occasion may require. Let some person follow with a spade or something of the sort, and turn up a bit of sod at every alternate move of the level, by which means you will have a bit of sod as a mark, at about every 10 feet. Begin say at B, fig. 1, and proceed as directed, and on a flat piece of ground you will probably produce a line thus, BC. The arrows marked on the line show the way the water is to be made to run on in the gutter line; to obtain which you must deviate from precise levelling, and allow the plumb-line to drop a little before the level mark when you are inclining down the meadow, and a little behind it when you are inclining up the meadow. This will have the effect of running the water out of the low places, and upon the high places. Care must be taken in levelling to follow out the indications of the level, however crooked and curved the line might appear; and by all means to avoid going across every elevation, and to avoid every disposition to make the line straight. Every straight cut that is made of that sort will have the effect, more or less, of causing a dry spot below the gutter, or a pond above it.

Having completed that line, return to the side you first began, and by no means level backwards. Return, say to D, which should be about 10 paces down from B; and by proceeding as in BC, you will very likely produce the line DE. The consequence will be, Irrigation.

Irrigation, that G and E are too far asunder; you must therefore begin at F, and proceed by line FG. I have supposed the middle of the meadow to be lowest, and the meadow itself to be flat, rising on each side of the middle by two gentle undulations, reducing the lines of gutter to curve very considerably. The nature of the ground is supposed to make it necessary now to begin at H, and to produce III. It will now be perceived that D and I are too far asunder, making it necessary to introduce Ks, beginning at K. Then proceed to finish out the higher side in like manner.

To avoid crowding the figure, I shall draw it anew, with a few alterations introduced for the purpose of showing the next process to advantage.

Let fig. 3 represent a meadow, with all the lines of fig. 1 marked with the pencil and plunged, but not "turned out"; the lines will be sufficiently perceptible to manage the next proceeding. It will be perceived that the curves of the lines form a series of loops, and that the undulations of the meadow are pretty well mapped out by the curves going down around the hills and up around the valleys. You can at once perceive where the water is principally wanted, viz., just above where the curves form the greatest downward bend. In the place before us it is at A, fig. 3. The next thing to be done is, to draw the lines which, upon an average of the whole, will be at right angles to the level; but in each particular line will deviate from the right angle, more or less, according as the ground is more or less irregular. The plan is to lay out one plough to the right of me, and then walk on before, and, by dragging my feet, leave a sufficient stain to mark where the plough must follow. Care must be taken to go as nearly through the centre of the downward loops as possible. In order to do this first cut the lines 1, 2, 3, 4, 5, and then fill up the intervals by cutting a, b, c. They should be from 10 to 15, or more, paces apart, according to the taste of the operator. I do not at all like them to be farther apart than 15 paces, but some persons think that by placing them closer together you cut off too much land.

The next business is to bring the water after just lifting the turf out of the gutters already cut. I use first a spirit-level, and set a mark every 2 poles, allowing the gutter to drop 1 inch or 2 inches if the nature of the ground will allow of it; but not less than 1 inch will do at all. A much larger gutter is required at 1-inch drop than at 2 inches, and, besides, it will not run itself dry so well when the water is turned off. The 2-inch drop gutters will run the water off directly; the 1-inch will scarcely do it at all. It would not be hard to the supply of water required at the farther end. In the case supposed in fig. 3, it is wanted on the rising ground, at the farther end A; therefore the gutter should drop that way accordingly (and in proportion), and be of a good size; but if the water is wanted chiefly at the beginning end of the gutter, the drop need not be so much, and the gutter should taper away so as to end nearly in a point.

The next consideration should have regard to the size of the stream. If it is enough to water the whole place at all times, one gutter, of sufficient size to do the work, should be made; and to do it without stops; stops in a gutter are decidedly objectionable. Where the stream is small, make a leading gutter, and take out from it taper gutters, each of a size suited to the stream when at its smallest, so that when the stream increases (from rain or any other cause), so many taper-gutters may be used as will dispense the whole stream. The leading-gutter will continually decrease in size from the beginning to the end, i.e., from the place where the first taper-gutter is taken out of it, and finish in a tapering water-gutter itself at last (see fig. 4).

AB is a carriage-gutter as far as c, and a watering-gutter from e to B; a and b are watering-gutters taken out of it. When the stream is small, a stop at I will cause it to work in c; a stop at 2 will work in b; without any stop it will work in cB. If the stream is too much for cB, it will work b at the same time; and should there be water enough, it will also fill a without any stop at all. Care should be taken not to make AB larger than just to carry the full stream wanted; and in every case when the gutter is got Irrigation too large by frequent cleaning out, cut it anew on one side or the other.

In levelling, after having marked every 2 poles with the spirit-level, mark the ground between with the plumb-level every 10 feet or so, and cut accordingly. Make the hedge-trough a carriage-gutter wherever it can be done conveniently, taking care always to make the water run in them when so used; and by no means to have stagnant water in the troughs. Covered gutters made with large tile could also be substituted for the deep open carriage-gutter, where it is necessary to cross the middle of meadows; it would thus obviate the danger of the open gutter to sheep and lambs; and the extra expense would be partly compensated, as the tiled-gutter would never require the annual "cleaning out."

General rules cannot be laid down to suit every circumstance that will occur, but practice and an ingenious mind will decide that which is most fitting on each occasion.

In watering with a small stream which happens to be insufficient for the whole meadow, the water must be confined to ground determined on by stops in the two perpendicular gutters which run on the two sides of it, thus:

Fig. 5 is a section of the net-work of gutters; AB is the carriage-gutter; c is a taper watering-gutter, to the extent of which the water is supposed to be determined to be confined; &c., &c., are the feeding gutters (perpendicular to the levels); the cross-gutters are the "level" ones; b and e serve as the two side gutters of the proposed section to be watered. The water is confined to the ground between them by stops at the crossings, arranged thus:—b is a crossing on the feeder (fig. 5); and e is a crossing on the feeder (fig. 6); 1, 2, 3, 4 are stops, the purpose of which is obvious enough. The arrows show the direction the water is made to run. The stops are places of the turf taken out of the gutters, which, being cut with a "die," of course fit the gutters with exactness; by this means any stoppings that may be required are done instantly, without any trouble or loss of time.

The gutters are not to be cut in the same places two years following, but on one side as near as can be conveniently done, say about a foot and a half from the former ones; and the turf of the new gutter need not be in the old one, taking care not to cram the old gutters too full. By this means the gutters are always new and always the proper size. If they be the right-hand side and above one year, the next year they should be cut the left-hand side and below; thus they will always retain their original position, and be as efficient at any future period as they were the first year they were made.

The objection generally raised against this plan is, that the only carriage-gutter being at the head (highest level) of the watered ground, the best of the water is expended on the first part of the meadow (which is generally the best and healthiest land), and the lower part of the meadow (which we have said might want it most), is irrigated with the water after having been deprived of its best materials. This objection is more plausible than valid; experience constantly denies that such is the result. I have always seen the lower parts of meadows formerly on the old system improve when put under this system, for however gutters on the old system might be provided for carrying the water down to a certain place, the machinery is so cumbrous that it is seldom used; whereas there are so many heavy stops and bays to be interfered with, to be removed, adjusted, put in and readjusted, and so on, that it is seldom undertaken—seldom or never used. What is wanted is a machinery that can be used readily—with pleasure and not with difficulty. The plan I advocate is just such a thing; it is easy to use, and, therefore, pleasant to do; and, for that reason, sure to be done. And I shall presently show that it is quite effectual for the purpose even of carrying the water fully charged with matter in solution to the extreme distance desired. In the first place, I must admit that the stones, gravel, grit, and even sticks and leaves with which a stream might be choked in case of flood, would not be carried to the extreme end of a meadow by the means I employ; but then I say they ought not; and I may add, in the case of the old plan, they are not; although gutters are cut ostensibly for that purpose, they never answer to the effect of carrying the sediments material. This is much better than allowing violent gusts of water to create a number of artificial hills and gullies in the usual way. It is well known (to those who know practically anything about it) that, when water is allowed to descend a patter in a full violent stream, it frets the earth away from the sides and bottom of the gutter, and the material is washed down to settle when the current ceases to rush, thus causing two unsightly evils—a deep gully in one place, and an inconvenient hilllock in another.

It will be proper now to call attention to the manner in which the water is carried, with its suspended matter, to the extreme end of the meadow by the plan we are pursuing. You will observe that the ground is covered by a sort of net-work of little gutters, from the "leading-in" gutter at the head, to the extreme end of the piece of land lying foremost from that leading-in gutter; one set of gutters, as we have shown, being, in a sort, parallel to each other, intersected by gutters at right angles to them, and also parallel to each other; this would be strictly true were the surface strictly a plane surface; but this being very rarely the case, both sets deviate from a strictly parallel condition (as we have shown), in order to meet the undulations of the ground; these deviations compensate each other on the aggregate. Now, instead of carrying the water "down to the lower end" by means of one large gutter, and then dispersing it by another large gutter (a lateral course), we do it by twenty or so little gutters which feed the dispensing gutter about every ten or fifteen paces; being so small they never fret away; being merely cut once every year they never increase in size. These advantages are too manifest to require pointing out.

The peculiarities for watering on our plan are perpendicular sections (I call them so for want of a more appropriate term), i.e., from the "leading-in" gutter to the end of the pieces—the running way of the water; and several lateral sections. That is, our section will be a, b, c, d (fig. 7), for one section, and b, e, f, g for another; and never 1, 2, 3, e, d, f. The water is not impaired in quality while running down these upright gutters, 4, 5, 6, 7.

We see the reason of this while we keep in memory that water is only good (as water) from two circumstances,—viz., 1st, from the purity of its composition (freedom from mineral properties), in which case the water will be as good at last as at first; and, 2ndly, for what it holds in solution, not for what it carries in an insoluble state, for that should be deposited. Now, as long as this water is kept in motion it carries its solved substances with it, and the plant (grase) that takes up the material solved takes up the water along; thus as the water loses its quality it also loses its volume, partly by evaporation and partly by absorption by the grases; consequently the water that remains must be just of the same quality as at first.

I have not tried any analytic experiment to prove the truth of what I have here stated; nor do I think it necessary to do so, as it is of no consequence whether it be true or not to a few quarts of diminution more or less; but this we know, water does evaporate, and that vegetables do decompose water for their own nutrition; and we know that evaporation carries off little or none of the solved matter. Upon this I found an argument, and take it as proved, that the water diminishes in volume as well as in quality, and that if these diminishments went on in exact ratio, then the water would remain pure under all circumstances, precisely of the same quality; and that for all practical purposes, which are the only ones under consideration, it does so remain.

The most satisfactory proof of the truth of this argument is found in the answer given by the meadows themselves, viz., that it is true. Experience has assured that the above reasoning is correct; the water is good to the last.

It is very difficult to prove it by experiments in nature in every case. The water will act best upon the best land; therefore to expect water to exhibit as much good effect on the lower end of a meadow, where the soil is inferior in quality, as it shows on the higher end, where the soil is superior in quality, is to expect what reason ought not to ask, and that to which nature will never respond.

But these small gutters are sufficient when the little stops are taken out of the perpendicular gutters, and the level gutters are stopped so as to confine the water to the perpendiculars, to carry down as much water as ought to be carried down. The level gutter of a lower section (if it is determined that a lateral section shall be watered), instead of being fed by a large stream at the end, is supplied every ten or fifteen paces by one of those little gutters, thus giving an uniform supply throughout the length of the level gutter. A larger supply than this will be useless, and, in a good year, you do not need to reach the surface of your land, you want to irrigate it. But this fashion of sending down the water is not what I advise; I only say it can be done if required. I advise that the sections begin at the head; a surplus will be found to run into the little gutters sufficient for the land below.

When the water is shut out from the "leading-in" gutter it is not necessary to move any of the little stops; the same perpendicular gutters that are effectual to run the water on, are as effectual to run it off, leaving the surface of the meadow dry and solid—a most manifest advantage.

The water is evenly distributed over the surface of the land by these minute gutters, which are made to follow all the undulations of the land, which can never be done by the large gutters; and also, from the draining effect of the perpendicular gutters, the water is never suffered to accumulate in ponds. The water on the surface is, therefore, never "over-shoe" anywhere.

These gutters are no way dangerous to sheep or lambs, are never in the way of mowing, have an elegant rather than an unsightly appearance, are not perceived either in raking or carting, and suit the horse-rake or hay-making machine admirably.

I am not aware of any circumstances under which this has not the advantage over the "old plan." For wetting the ground in summer this plan has the decided superiority, as less water will do the work than will be required merely to fill the level gutters under the old system. It will be proper to remark, that grass so raised is scarcely safe for sheep; it certainly rots their feet; I found out this at the expense of many sheep. It is perfectly analogous to a plentiful crop in a long drought; grass resulting thus proves equal as fatal to sheep as that produced by summer watering and dry season, and vice versâ.

Where the stream is small, a pond should be made, capable of holding as much water as will run a good stream for four hours or more; such a pond would make such a stream valuable as is really insignificant in itself. A small stream so collected will damp over thirty acres sufficiently well to secure a crop of hay.

I would just advert to the fact that the leading-in gutters can be so arranged as to tend themselves in cases of flood; but the opportunity does not present itself just now for going into that branch of the subject.

This comparatively cheap system is rapidly extending, and is much more worthy of imitation than the ancient and costly bed-work plan. Though it was at first chiefly used on the sloping sides of the Devon and Somersetshire valleys, it has been lately applied to levels as flat as the banks of the Thames. A new meadow of Lord Poltimore's on this system has a fall of not more than 1 in 528. And when it is considered that a catch-work meadow can be formed at a cost of about £1-4 an acre, while on the bed-work system it will cost from five to ten times that sum, there cannot be a moment's doubt of the comparative advantage of the two systems for general adoption.

MANAGEMENT OF WATER-MEADOWS.

The formation is not the only difficulty attending water-meadows; their good management is a nice business, and essential to the deriving of benefit from them. It must be confessed that much ignorance and negligence prevail in their management; and when the risk is considered of losing the whole of the fine herbage, and getting coarse in its stead, by bad management, a skilful irrigator is a character who ought to be highly appreciated. The particulars which Irrigation require constant attention are,—the state of the water in the river, whether there is sufficient to water the whole, or only a part of the meadow; the regulating of the sluices, so as not to permit more nor less water than the part of the meadow intended to be watered requires; the length of time the water should be allowed to remain on the meadow at different periods of the season; the proper time at which hay harvest and pasturage should commence and terminate; the state and nature of the soil to be irrigated, whether porous or impervious; and the removal of all minute obstructions to the perfect irrigation of the meadow.

Every size of river is not equally suitable for irrigation. A large flowing stream, supplying sufficient water at all times, affords facilities for irrigating a part or the whole of a meadow, much better than a brook which swells and falls with every shower of rain. At the same time, whatever may be the command of water, it is an error to attempt to irrigate too large a surface at one time. The attempt to force a larger quantity of water than the feeders and drains can easily convey, will end in deluging one part, whilst another will be stinted; and where there is inequality of irrigation, there will be inequality in the quantity and quality of the grass. Where there is an ample supply of water, therefore, no more ground should be irrigated at one time than can be covered equally to the requisite depth by the natural force of the water. Where the supply is short of this, which is more frequently the case, the water should only have as much ground allotted to it as it can effectually irrigate. The intervals between the irrigations will be greater when the supply of water is scanty than when plentiful; but notwithstanding this, the effects produced on the meadow in both cases may be nearly equal, according as the weather is favourable or otherwise. The adjustment of the water by the sluices is a delicate operation under every circumstance, but particularly so when there is at times a deficiency of water. The falling or rising of the water in the river requires particular attention, and the changing of the water from one part of the meadow to another, or even from one bed to another, according to its abundance or deficiency, particular dexterity. Attention to the sluices for a short time every day, will obviate many risks of bad management. A great error may be committed by permitting the water to remain too long on the ground at a time. Unless the ground gets the air and becomes dry at stated periods, the finer grasses will be destroyed, and those of coarse quality will spring up. The watering may be continued for as long as fifteen days in the beginning of the irrigating season in November, but the time should be gradually lessened till March or April, when it should cease altogether. Between the intervals of watering, the land should be laid completely dry. Precautions are particularly necessary in letting the water off and on in frosty weather, frost taking quick hold of wet grass land, and throwing the plants out by the roots. The water should be let off on the morning of a dry day, and the land thus becoming dry in the course of the day, the frost will not injure the grass at night. Or, what is a still safer method, the water should be taken off in the morning and put on again at night, but few persons will take the trouble of attending so minutely to irrigation. In spring the new grown tender grass will be easily destroyed by frost, if the utmost attention be not paid to the state of the ground, either by protecting it with water, which is the surest protection it can receive, or making the ground thoroughly dry in dry weather. There is another error which should be guarded against: when water remains too long on the ground in the spring, it generates a white scum, of the consistence of melted glue, which, when left on the grass, inevitably destroys it. Instances may be observed of water being permitted to remain on meadows from the autumn till eight or ten days before the cutting of hay. The consequences are, that the hay is of the coarsest quality, and the early bite for sheep entirely lost. It seems to be a judicious recommendation to depasture the early grass on water-meadows with ewes and lambs in March and April, and to eat it barely down before May with a heavy stock. On good land, and in good seasons, a second and even third crop of feed may be got before the 1st of May, the water being let on after each feed. After that the grass is allowed to stand for hay; but it should be irrigated for a few days to clean the pasture. There is some doubt that grass, after being irrigated in summer, will affect sheep with rot; but whether that which has been irrigated in May, before the hay has been cut down, will so affect them on the aftermath, is not so decidedly known.

When it is determined to irrigate, the drains and feeders should be previously inspected, all obstructions removed, and dilapidations amended. Whatever difference of opinion may exist on irrigating at this particular period of the season, all irrigators are agreed that early irrigation in autumn produces greater effects than late, and that water should be used largely during the winter, and scantily during the spring. It is possible that the benefits derived from early irrigation, especially after rains, may arise from the good effects of manure of various kinds, accumulated on the land during summer, being washed down by the rains, and mixed with the irrigating water; and it is certain that abundant irrigation in winter protects the grass from cold, as the temperature of grass under water in winter is seldom under 40° Fahr. The signs of early and luxuriant vegetation observable on water-meadows in spring, when the rest of the ground may be covered with snow, evince the warmth communicated by the water. After the hay is carried off, the water is sometimes let on, to promote the growth of the aftermath, which it will no doubt do; but the rank grass encouraged by this summer irrigation will undoubtedly rot sheep. Where sheep are kept, and intended to depasture meadows, there should be no irrigation in summer. "Damping" the land only is allowable. Cattle are not affected as sheep.

Should the irrigation be postponed till the autumn, in the beginning of October the first duty of the irrigator is to see that all the feeders and drains are cleared of every obstruction, occasioned by the treading of sheep or cattle. The sluice is then drawn up, and if the water be abundant, the conductor and feeders will be filled with water in about half-an-hour. The motion of the water should first be adjusted in all the conductors; then in the feeders nearest the upper part of the meadow, and then in the lower ones in succession. The sluices regulate the water in the conductors, and the position of the stops regulates the water in the feeders. The stops should be so placed as to cause the water to overflow the sides of the feeders, by making the openings at the sides of the stops wider or narrower. This first general inundation will show any irregularities on the surface of the meadow; and that some irregularities will exist in the best-constructed water-meadows, it is not in the power of art to prevent. The earth in the filled-up hollows will subside, whilst the hard portions of ground which have been reduced will maintain their new shape. The irregularities should now be marked and rectified in the ensuing summer. At least three such adjustments of the water are necessary before an irrigator should be satisfied that the meadow is properly irrigated with the requisite depth of one inch of water. This quantity of water should be continued over the meadow during October, November, December, and January, from fifteen to twenty days in succession, according as the weather is fresh or frosty, wet or dry. Between every such interval, the meadow should be laid thoroughly dry for five or six days to give the grass air; and should the weather threaten a lengthened period of hard frost, the watering should be entirely discontinued for the time; for in thawing, the sheet of ice which covers the sur-

face of the meadow will draw every plant of grass out by the roots, and make the soil like a mass of fermented dough. In Devonshire, however, the rule is neither to lay on or take off the water in frost. During the period of irrigation, the meadows should be regularly visited and inspected once in every three or four days, to correct any deviation from regular watering, such as may arise from collections of weeds, petty depredations of men and beasts, sticks, stones, or leaves, that may have fallen in and been detained in the conductors and feeders.

In February, great attention is required from the irrigator, as the grass will now begin to vegetate. The periods of watering must be shortened, and those of drying must be proportionally lengthened. White scum, frost, and such like evils, should be carefully avoided, as the tender grass will sensibly feel their injurious effects.

In March, the same precautions are requisite; but in the south of England, where grass is sufficiently abundant for stock in this month, the irrigation should be dispensed with. In Scotland, irrigation may be continued all April, but with such caution, that the water should be allowed to run only five or six days at a time, and gradually lessened towards the end of the month; and in the beginning of May dispensed with altogether, and the meadow laid thoroughly dry for the summer. It should be borne in mind, that this is the most trying season for young grasses in Scotland; and also, that if watering is continued after this month, the blades of grass will be covered with a gritty sediment, which not only injures the quality of the hay, but renders the mowing of it a difficult process.

The annual expense of keeping a water-meadow in repair may be about five or six shillings an acre. The greatest expense in keeping a meadow will be incurred in the second year, on account of the sinkings of those places which had been made up with loose earth having to be brought up to the common inclination.

III. SUBTERRANEous IRRIGATION.

This species of irrigation is so named because the supply of water is derived from under the surface of the ground to the upper soil. It is only applicable to perfectly level ground, so raised above the supplying river as to admit of a complete drainage of the field to be irrigated. This system of irrigation consists, in the first place, of ditches being formed around all the sides of the field. These act the part of conductors when the field is to be flooded, and of main drains when it is to be laid dry. The water flows from the ditches as conductors into built drains or conduits, formed at right angles to them, in parallel lines through the fields, and it rises upwards in them as high as the surface of the ground, and again subsides through the soil and the conduits into the ditches as main drains, and thence into the river. Sluices are requisite to convey the water from the river into the ditches. This submersion, as it may be called, rather than overflow, of the ground in water, must be conducted with great care, and the water let on very calmly; for were the water let on or taken off with a forcible current, the finer particles of the soil would be detached, and carried off into the river. Indeed, however carefully the operation may be conducted, the only advantage derived from this species of irrigation is the moistening of dry ground in dry weather, which would otherwise be parched up; and in this respect, the operation is best conducted in summer, and is as applicable to arable as to pasture land. It can therefore be of no importance to subterraneous irrigation, whether the water be clear or turbid, since all the sediment must be seethed through the soil, before it can possibly reach the surface of the ground. In the Fen counties both arable and pasture land are benefited by the system, the depth of water in the ditches which Irrigation bound all the fields being regulated with a view to this.

IV. WARPING.

Warping is the overflowing of level ground with muddy water within tide mark. Of course, it can only be practised near the sea, and most frequently it is attempted within the estuaries of large rivers, which have flowed through alluvial cultivated countries. A good idea of the process of warping may be got by sailing up the Trent from the Humber to Gainsborough. The banks of the river were constructed centuries ago to protect the land within them from the encroachments of the tide. A great tract of country was thus laid comparatively dry. But while the wisdom of one age thus succeeded in restricting within bounds the tidal water of the river, it was left to the greater wisdom of a succeeding age to improve upon this arrangement, by admitting these muddy waters to lay a fresh coat of rich silt on the exhausted soils. The process began nearly a century ago, but has become more of a system in recent times. Large sluices of stone, with strong doors, to be shut when it is wished to exclude the tide, may be seen on both banks of the river, and from these great drains are carried miles inward through the flat country, to the point previously prepared by embankment, over which the muddy waters are allowed to spread. These main drains being very costly, are constructed for the warping of large adjoining districts, and openings are made at such points as are then undergoing the operation. The mud is deposited, and the waters return with the falling tide to the bed of the river. Spring-tides are preferred, and so great is the quantity of mud in these rivers that from 10 to 15 acres have been known to be covered with silt from 1 to 3 feet in thickness during one spring of 10 or 12 tides. Peat-moss of the most sterile character has been by this process covered with soil of the greatest fertility, and swamps which used to be resorted to for leeches are now, by the effects of warping, converted into firm and fertile fields. The art is now so well understood, that by careful attention to the currents, the expert warp farmer can temper his soil as he pleases. When the tide is first admitted, the heavier particles, which are pure sand, are first deposited; the second deposit is a mixture of sand and fine mud, which, from its friable texture, forms the most valuable soil; while lastly the pure mud subsides, containing the finest particles of all, and forms a rich but very tenacious soil. The great effort, therefore, of the warp farmer is to get the second or mixed deposit as equally over the whole surface as he can, and to prevent the deposit of the last. This he does by keeping the water in constant motion, as the last deposit can only take place when the water is suffered to be still. Three years may be said to be spent in the process, one year warping, one year drying and consolidating, and one year growing the first crop, which is generally seed hoed in by hand, as the mud at this time is too soft to admit of horse labour.

Its immediate effect, which is highly beneficial, is the deposition of silt from the tide. To insure this deposition it is necessary to surround the field to be warped with a strong embankment, in order to retain the water as the tide recedes. The water is admitted by valved sluices, which open as the tide flows into the field, and shut by the pressure of the confined water when the tide recedes. These sluices are placed as low a level as possible, to permit the most turbid water at the bottom of the tide to pass through a channel in the base of the embankment. The silt deposited after warping is exceedingly rich, and capable of carrying any species of crop. It may be admitted in so small a quantity as only to act as a manure to arable soil, Irrigation, or in such a large quantity as to form a new soil. This latter acquisition is the principal object of warping, and it excites astonishment to witness how soon a new soil may be formed. From June to September, a soil of three feet in depth may be formed under favourable circumstances. These circumstances are summer, and the very driest season and longest drought. In winter, and in floods, warping ceases to be beneficial. In ordinary circumstances, on the Trent and Humber, a soil from 6 to 16 inches in depth may be obtained, and inequalities of 3 feet filled up. But every tide generally leaves only one-eighth of an inch of silt, and the field which has only one sluice can only be warped every other tide. The silt, as deposited in each tide, does not mix into a uniform mass, but remains in distinct layers. The water should be made to run completely off, and the ditches should become dry, before the influx of the next tide, otherwise the silt will not incrust, and the tide not have the same effect. Warp soil is of surpassing fertility. The expense of forming canals, embankments, and sluices for warping land is from £10 to £20 an acre. A sluice of 6 feet in height and 8 feet wide, will warp from sixty to eighty acres, according to the distance of the field from the river. The embankments may be from 3 to 7 feet in height, as the field may stand in regard to the level of the highest tides. After the new land has been left for a year or two in seeds and clover, it produces great crops of wheat and potatoes.

In Great Britain, irrigation is practised to the greatest extent in Devon and Somerset, Gloucestershire, Wiltshire, and Dumfriesshire, and partially in some other counties. In England it has long been successfully practised. Into Scotland it is comparatively of recent introduction.

Warping is only practised in Lincolnshire and Yorkshire, in the estuary of the Humber, in the Rivers Trent, Ouse, and Dun, which flow into it. The silt, which is in great abundance in these rivers, is doubtless worn off the diluvial soils and chalk strata by the action of the tide. Floods invariably injure its quality, which is in the highest perfection in the driest summers. Apparently it is a mixture of sand, chalk, and clay, for it cakes on drying, and will cleanse cloth of grease like fuller's earth. By analysis the principal ingredients were found to be a fine sand, a considerable portion of lime, some mica, and a minute portion of saline matter.

Subterraneous irrigation is chiefly practised in drained morasses, which are apt to become too dry in summer, by closing up the mouths of the main drains, and causing the water in them to stand back in all the drains till it rises up to the soil. It was recommended by the late celebrated engineer Mr Rennie, to be practised on some extensive fens which he had drained in Lincolnshire, near Boston. To irrigate effectually in this manner, it is necessary to build the mouths of the main drains with strong masonry, and erect sluices for the retention of the water in the drains. This species of irrigation may also be attempted on any flat piece of ground resting on a gravelly bottom, by means of ditches which surround it, and which can command water from a lake or river. Turnips or potatoes, or any kind of crop, whether drilled or not, might be beneficially watered in this manner in a dry summer.

ADVANTAGES OF WATER-MEADOWS AND WARPING.

The advantages derived from water-meadows and warping, as stated by authors who have written on those subjects, almost exceed credibility.

In 1802 Mr Smith laid out a water-meadow on the Paisley farm, near Woburn, Bedfordshire, for the Duke of Bedford, and in 1803 its produce was as follows:

- In March, 240 sheep for three weeks, at 6d. each per week. - In June, mowed 18 tons hay, at £1.4 per ton. - In August, mowed 13½ do. - In September, 80 fat sheep for three weeks, at 4d. each per week. - It then fed lean bullocks, the feeding not valued, equal to £1.16. 13s. 8d. per acre.

Mr Pusey gives an instance of a field of two acres on his home farm in Berkshire, good land naturally, but so much out of condition, that latterly the hay crop had been hardly worth cutting, the produce of which, after irrigation, he estimates as follows:

| Days' keep of a sheep | Sheep | |----------------------|-------| | First penning, sheep put on, but grass too strong to feed, and made into hay, say only | 3,000 | | Second feeding, 400 lambs for eight days, say 240 sheep | 1,920 | | Third penning, 250 sheep for ten days | 2,500 | | Fourth do., 250 sheep for fourteen days | 3,500 |

The total amounts to 5 months' keep for 73 sheep on two acres, thirty-six sheep to an acre. Mr Pusey compares the result with the feed afforded in Lincolnshire by a thoroughly good crop of turnips, which are said to keep ten sheep an acre for five months,—and with grass land of good quality, which fattened seven sheep to an acre in the five summer months. Admitting the seven fattened sheep to be equal to fourteen of his kept merely in store order, the account would stand thus, comparatively: ten sheep on an acre of turnips, fourteen on an acre of superior grazing land unwatered, and thirty-six on an acre of moderate land watered. Mr Pusey's investment in irrigation, in one of the dry inland counties, has paid him a return of 30 per cent. on the capital expended.

These two cases may suffice as examples of successful irrigation in England. The following cases occur in Scotland, a country, from its irregularity of surface, not naturally suited to that species of improvement. Nevertheless, in all the pastoral districts, both in the north and south, an abundance of early food in spring for ewes and lambs might be obtained, by judicious irrigation, in every valley which contains a river. In mountainous districts the rivers may not supply the richest quality of water for irrigation, but there the soil on the margins of rivers being generally of friable loam, would be peculiarly benefited by irrigation. Such land is invariably sound for sheep when drained; and if made dry, and then irrigated, it would, early in spring, and indeed throughout the summer, afford the finest quality of the richest herbage. Water-meadows in such situations could be inclosed by themselves, and they could supply hay, if required, for the sheep-stock in winter, or be pastured at pleasure by any kind of stock during the summer.

To begin with an instance of simple irrigation in a pastoral district. "Fallaw Meadow, on a large sheep-farm belonging to Sir George Montgomery, Bart. of Machiehill, in Peeblesshire, containing fifteen acres, was inclosed from moorland in 1816; and by collecting the water from the surrounding sheep-drains, five acres are partially irrigated, and the remaining ten are top-dressed with the manure made from part of the produce which is consumed in winter by the sheep of the farm, in a wooden shed near the meadow. By this simple method of improvement, fifteen acres of common sheep-pasture land give the proprietor from three thousand five hundred to four thousand stones of hay per annum, averaging sixpence per stone. What an immense advantage to a sheep-farm! By this simple process of inclosing, and cutting a few small feeders and drains, the owner is enabled to provide food for his flock, when his less fortunate neighbours' sheep must either starve or be supplied from the farm-yard; but I am afraid there are very

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1 Smith's Essay on Irrigation. Irrigation, few sheep-farmers who are so fortunate as to have any hay beyond what is requisite for stock at home. Sir George fed the same number of sheep on the farm as he did before the meadow was taken off and inclosed; and I am fully persuaded that the same improvement might be made on almost every sheep-farm in Tweeddale, for in almost all of them, there are situations where fourteen or fifteen acres might be inclosed and partially irrigated, as in every pastoral district there are numerous rills which might be easily collected and used to the greatest advantage, at a very trifling expense; so that, instead of being obliged, in snowstorms, to send fifty thousand sheep to a milder climate in the southern parts of Dumfriesshire (where owners are obliged to be at the mercy of their southern neighbours, not to mention the very serious injury the flocks receive by long and fatiguing journeys), by adopting the above system of improvement a considerable part of the losses generally sustained every year would be prevented.

Here is an instance of the conversion of peat-bog of little value into a water-meadow of great value. "Sir Thomas Gibson Carmichael, Bart. of Castle Craig, commenced, in the year 1817, by forming five acres with the plough and spade into regular bed-work. The land, in its natural state, was a complete bog, valued at eight shillings of yearly rent per acre. The formation was difficult, on account of the great number of deep peat-holes which were obliged to be filled up, to bring the surface to a proper level. The expense of levelling and forming the beds was £6 per acre; the crop of hay was 466 stones, of 22lb. per stone, per acre, valued at fivepence per stone, and the after-grass at 18s. per acre, making £10, 12s. 2d. per acre of gross produce."

But this enumeration of the several cases of successful irrigation would be incomplete, were the water-meadows in the neighbourhood of Edinburgh omitted to be particularized. The city of Edinburgh stands on an eminence, which commands the cultivated country around it. Commanding as the situation is, water from the Crawley Spring, in the Pentland Hills, situate at seven miles' distance, flows to the top of every house in the city. A ready means is thus provided of washing away all the filth of the houses and streets, which is conveyed in large sewers to the lower end of the town, where their contents are made to irrigate many acres of naturally rich and also of poor soil. Probably upwards of 200 acres are thus irrigated for the production of grass for the cowfeeders who supply milk to the inhabitants. The rent for which these meadows are let in small portions to cowfeeders varies on an average from £20 to £30 per acre. Some of the richest meadows were let in 1835 at £38 per acre; and in that season of scarce forage, 1826, £57 an acre were obtained for the same meadows. The largest portion of these meadows, about one hundred and thirty acres, belongs to the estate of Craigintanny; part of them, comprising land now of the richest quality, having been thus watered for nearly a century, and part of them of the poorest sandy soil. The waste land called the Figget Whins, containing thirty acres, and ten acres of poor sandy soil adjoining them, were formed into water-meadows in 1821, at an expense of £1000. The pasture of the Figget Whins used to be let for £40 a-year, and that of the ten acres at £60. Now the same ground, as meadows, lets for £15 or £20 an acre a-year, and will probably let for more as the land becomes more and more enriched. It is stated by Mr Stephens, that one hundred and ten acres of Craigintanny meadows, in 1827, yielded a profit of £2300. The repair of these meadows costs from ten to fifteen shillings per acre, which is comparatively a large sum for repairs, but then they are not only watered during the winter, but for two or three days between the intervals of cutting the grass during the summer. The grass is cut from April to November, every three, four, or five weeks, according to the richness of the vegetation. It is exceedingly tender and succulent, and suitable to the production of a large quantity of milk; and were it not frequently cut, it would fall down, and soon rot at the roots.

After these striking instances of the advantages which are derivable from irrigation in a pecuniary point of view, by largely increasing the rent of land, must be mentioned the advantages which are derived from a large increase in the produce of the soil. The early grass in March, which could only be fostered by irrigation, is of the most essential use to ewes and lambs, and it offers an excellent substitute for the artificial grasses, which are usually obliged to be heavily stocked in early spring, when they are unable to bear it; and in truly pastoral districts, where artificial grasses are cultivated to a limited extent, and where old grass is generally long in springing, the breeding stock of sheep is apt to suffer in spring; but an irrigated meadow would not only supply early and abundant food, but it would enable the store-masters to raise an early crop of lambs. The large crop of fine hay which is subsequently cut from water-meadows after the pasturage of the early grass, also insures the safety of the flock, and the growing condition of the herd, in the severest winter; whilst it, at the same time, supplies the manure which fertilizes, to an increasing extent, the land kept under arable culture. Whether, therefore, in pastoral districts, or in the neighbourhood of large towns, or wherever an abundant supply of river water through an alluvial cultivated country can be obtained, irrigation will certainly repay, in a short time, all the expense and trouble which are necessary for its preparation.

The quality of the water is an important element in the process of irrigation. It has been alleged that whether water is clear or turbid, irrigation is of service to grass land. There is much truth in this allegation; but it does not declare the whole truth. No doubt moisture alone is of great service to the vegetation of grass on sandy soils in a dry season; but a deposit of mud along with the moisture would surely not benefit the grass the less; nor would it injure the bare soil.

The waters of the Nile and Ganges would alone promote vegetation on their banks, the soils of which seldom experience the refreshing sustenance of rain; but the inundations of those mighty rivers would not be hailed with ecstasy and gratitude on the return of every season, were their waters devoid of the fertilizing mud with which they are largely impregnated. Major Rennell states that the Ganges contains a two-hundredth part of its volume of mud, and that it thus carries 2,509,056,000 cubic feet of it per hour. In like manner, the Nile contains a hundred and twentieth part of its bulk in mud, or 14,784,000 cubic feet of it per hour. It is impossible but that the water of all rivers contains at all times, even when purest, some sediment; but it is obvious that those rivers which flow through cultivated countries must contain at all times the greatest quantity of sediment. In this way the rivers of plains must contain more mud than the rivers of mountains; and hence irrigation exhibits the most favourable results in the plains. But were no other proof of the superiority of turbid over clear water for irrigation to be found, the luxuriant produce of the water-meadows in the neighbourhood of Edinburgh, which are watered from the common sewers of that city, would of itself supply a convincing illustration.

Similar results could never be derived from clear water; nor is it ever found so superabundantly rich as to be necessary to be treated like the water of those meadows next the town, where holes are dug in the ground, for the purpose of catching the grosser materials with which it is charged, before it is used for irrigation.

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1 Stephens' Practical Irrigator. 2 Ibid. 3 Ibid., p. 77.

V. HISTORY OF IRRIGATION.

Irrigation is at least coeval in antiquity with embanking and draining. It is probably of greater antiquity. Nature had, no doubt, first taught man the art of irrigation by the inundations of rivers; but nature could teach neither embanking nor draining. Egypt was the field which was first artificially irrigated. There the fertilizing effects of the water of the Nile, after its overflow, could not fail to attract the attention of its inhabitants, and teach a simple lesson to the Egyptians, who had only to imitate nature to secure the fertility of the soil lying beyond the reach of the inundations of the Nile. The remains of canals as capacious as the beds of rivers, which are still to be seen in that sand-desolated country, evince the gigantic efforts which had at one time been made by its inhabitants to irrigate that portion of their country upon which a drop of rain never falls to refresh its languishing vegetation. These canals traverse the whole country, and are so directed as probably to have been made to receive the water of the Nile, and conduct it to every part, the inequalities of the surface not being great in Egypt. The large lakes of Meris, Behire, and Marotis, all probably artificial excavations, had perhaps once formed extensive reservoirs to supply the canals after the Nile had retired within its own banks. At what time all these mighty contrivances were begun, history is as silent as on the origin of the pyramids. It is, however, related that Sesostris greatly increased the number of the canals, which must have been at a period of great antiquity, for he reigned about the sixteenth century before the Christian era. Greater efforts to promote irrigation were more urgent in Egypt than in most other countries; for no rain fell in that country to cherish vegetation; and rice, which forms the chief food of its inhabitants, could not be raised without a great supply of water.

It is therefore highly probable that the remains of great canals and lakes are indicative of the majestic scale with which the Egyptians had prosecuted the art of irrigation. It is, however, prudent to speak with caution on matters connected with the agriculture of ancient Egypt; for our knowledge of its husbandry is chiefly derived from hints contained in Scripture history, and not from its own historical records. The historian of Egypt, Herodotus, was a Greek, and lived at so late a period as the fifth century before the Christian era, long after the glory of Egypt had departed; whereas the Scriptures supply us with facts of Egyptian agriculture of much greater antiquity, isolated though they certainly are. Such circumstances as the following indicate the existence of irrigation in Egypt at a very remote period of the world. When Abraham and Lot journeyed together in search of a country to abide in after they had left Egypt, they agreed to separate, when they found that the land they were then in could not supply sufficient food for their united flocks and herds; and we are told that Lot chose the plain of Jordan, because it was watered as well as the land of Egypt. "And Lot lifted up his eyes and beheld all the plain of Jordan as thou comest into Zoar, that it was well watered everywhere, before the Lord destroyed Sodom and Gomorrah, even as the garden of the Lord, like the land of Egypt." Egypt never contained rivers to water it, there being only the Nile; so that the similitude between "the plain of Jordan" and "the land of Egypt," to the mind of Lot, must have arisen from the rivers in Jordan being as numerous as the canals in Egypt; and Lot having witnessed the fertilizing powers of the water of these canals in Egypt, naturally supposed that the rivers would produce a similar effect on the plain of Jordan. The Egyptians had been in the habit of watering their gardens as well as their fields, and this they accomplished at pleasure, by raising water with a machine which they worked with the foot. Simply as such contrivances were, and they are to be seen in Egypt at this day, they could not fail to be troublesome. Dr. Clark describes the Egyptians, when raising water for their gardens, as requiring to work stark naked, or only partially covered with a blue striped shirt. When Moses, therefore, described the promised land to the Israelites, he represented it as a land which was supplied with water in a natural manner, in contradistinction to the more difficult and artificial way by the foot in Egypt: "For the land whither thou goest to possess it, is not as the land of Egypt from whence thou camest out, where thou sowedst thy seed and wateredst it with thy foot, as a garden of herbs: But the land whither ye go to possess it, is a land of hills and valleys, and drinketh water of the rain of Heaven: And it shall come to pass, if ye shall hearken diligently unto my commandment which I command you this day, that I will give you the rain of your land in due season, the first rain and the latter rain, that thou mayest gather in thy corn, and thy wine, and thine oil."

By irrigation, the soil of Egypt had been rendered so fertile that Pliny compares it to that of the Leontines, formerly the most fertile part of Sicily. Certain it is that Egypt was very prolific in corn even in the days of Abraham, who had recourse to it in years of famine, and that was at least eighteen centuries before the Christian era.

Too little is known of the agriculture of the ancient kingdoms of Assyria, Babylon, Carthage, Phoenicia, and Greece, to enable any one to ascertain how they practised irrigation; but as they all had Egypt as an example in agriculture and the arts, it is probable that they had followed those practices in husbandry which were most suitable to their respective countries. The little that Xenophon says in his Anabasis of the husbandry of Persia, would lead to the belief that canals had been cut from rivers to irrigate the country after the manner of Egypt, and to this day the utmost labour and ingenuity are employed by the Persian agriculturists in the irrigation of their parched country.

The sagacious Romans, it is well known from the writings of their rustic countrymen, adopted irrigation on an extensive scale, as one of the best means of improving land. The oldest Roman rustic writer, Cato, expressed his opinion that the way to become rich quickly was "by grazing cattle well," and hence he gives the preference to meadows. He does not maintain that grass is the most valuable crop which the land can produce, for he only places meadows in the fifth degree of value, giving preference in this respect to vineyards, watered gardens, willow fields, and olive gardens, but that they yielded most profit in proportion to the expense attending them, and they were always ready; hence their ancient name, prata. Agreeably to this opinion, Cato recommends the formation of meadows, and particularly of water-meadows, whenever there is a command of water: Prata irriguis, si aquam habebis, potissimum facito. Columella recommends the same precept, and enters more minutely into the kinds of soils which should be converted into water-meadows, and of the nature of the surface best adapted to them, as well as the management of the water in the time of irrigation. "Land that is naturally rich," says he, "and that is in good heart, does not need to have water set over it; and it is better hay which nature of its own accord produces in a juicy soil, than what water draws from a soil that is overflowed. This, however, is a necessary practice when the poverty of the soil requires it; and a meadow may be formed either upon stiff or free soil, though poor, when water may be set over it. Neither a low field with hollows, nor a field broken with steep rising ground, are proper; the first, because it contains too long the water collected in the hollows; the last, because it

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1 Gen. xiii. 10. 2 Deut. xi. 10, 11, 13, 14. 3 Cat. cap. ix. Irrigation makes the water run too quickly over it. A field, however, that has a moderate descent may be made a meadow, whether it is rich or so situated as to be watered; but the best situation is where the surface is smooth, and the descent so gentle as to prevent either showers or the rivers that overflow it from remaining long; and, on the other hand, to allow the water that comes over it quietly to glide off. Therefore, if in any part of a field intended for a meadow, a pool of water should stand, it must be let off by drains, for the loss is equal, either from too much water or too little grass. But none of the Roman rustic writers give directions how a water-meadow should be made, nor say anything about the utility of sluices, although Columella gives minute directions about the formation of dry meadows. It does not appear, moreover, that they were acquainted with the raising of 'turf' and laying it down again for meadows, because they only recommend hay-seeds from the hay-lofts and cribs to be sown, and deprecate the watering and pasturing of cattle on the new meadows till the surface becomes hard. There is no specific notice taken by any of them of how long a period meadows should be watered, if one sentence of Pliny be excepted, wherein he directs that "meadows ought to be watered immediately after the equinox, and the waters restrained whenever the grass shoots up into the stalk;" but there is no hint whether they should be laid dry at intervals.

Pliny alone mentions watering before the first crop of hay is cut, on the principle that wet grass, whether wetted by water or dew, is cut more easily than dry. Noctilus roscidis secari melius. The Romans were in the custom of cutting their meadows at least twice a-year, in May and August or September, and making hay of both these cuttings; but meadows for forage were cut sometimes four times. The autumnal hay was emphatically called cordum, and being soft, and sweeter than hay come to its full growth, it was the kind most proper to be given to sheep in winter. The produce of the Roman meadows appears to have been very considerable, and it is therefore no wonder that they put such a high value on grass-land. Both Columella and Pliny estimate it a day's work for a man to mow a jugerum and bind 1200 bundles of hay, of four pounds each. According to a calculation made by Dr Dickson, these quantities would give a produce of 265 hay stones, of 22 lb. to the stone, per acre (416 imperial stones per imperial acre), of prepared hay, besides the autumnal crop and the rakings taken up afterwards, and which may be estimated at one-half more. This is not the proper place to describe the Roman method of making hay, which differed from the method of this country, but having alluded to hay having been bound in bundles, it may not be irrelevant to state that the Romans made up their hay into bundles of 4 lb. each before they carried it into the barns or hay-lofts, and that they never ricketed it but in rainy weather.

Immediately after the fall of the Roman empire, agriculture declined, and was kept in a very depressed state during the middle ages, which depression, with respect to agriculture, lasted about ten centuries. It need therefore excite no surprise that the general agriculture of Italy was not much improved, from what it had been amongst the Romans, till after the revival of letters. Irrigation was perhaps the only branch of agriculture which received improvement or extension before the expiration of the dark ages; and its improvement at that time was even confined to the north of Italy.

The irrigation of Lombardy to this day forms the principal feature of its agriculture. The Lombard kings, following the example of the Romans, encouraged and extended irrigation, and they were ably assisted by the inmates of their numerous and wealthy religious establishments. Under these favourable auspices, irrigation had been extended on a great scale in Lombardy as early as 1037; and such expert hydraulic engineers had the monks of Chiarevalle become, that they were consulted and employed as such by the Emperor Frederick I. in the thirteenth century; and, ever since, so assiduous has been the care with which the agriculturists in Lombardy have preserved entire, and in good working order, their water-meadows, that at the present day no other part of the globe can exhibit that operation on so grand a scale and in such excellent order, and producing so rich a pasturage, verdans throughout the year. The largest rivers in the north of Italy, the Po, the Adige, the Tagliamento, and others, are put under requisition for a supply of water in summer and winter, for the purposes of irrigation; the whole country from Venice to Turin being almost one continued water-meadow. But there irrigation is not confined to grass-land; water being also conducted between the ridges of corn-land, in the hollows between drilled crops, among vines, and over the flats appropriated to the production of rice; and it is also used to deposit mud, in the manner of warping, where it contains sediment. Irrigation naturally passed from Lombardy into the south of France, where it is used to raise many of the more valuable productions of the soil. Spain to this day employs irrigation to so considerable an extent, that few crops are there raised without it. Some water-meadows in the neighbourhood of Salisbury, in Wiltshire, which are said to have existed from time immemorial, have led to the belief that irrigation has been practised in Britain from the time of the Romans. It is, indeed, extremely probable, that had the Romans constructed such works during their sojourn in Britain, the pastoral habits of their Saxon successors would have preserved them from destruction. But be this as it may, it is certain that irrigation after the method of Italy was not extensively introduced into Britain till the sixteenth century, when it was attempted on a large scale in Cambridgeshire, on the estate of Babraham, by one Pallavicino, the collector of Peter's pence in the reign of Queen Mary, but who, on the accession of Elizabeth, had the art to turn Protestant, and purchase that estate with the balance of money which he had in his possession, amounting it is said to £30,000 or £40,000, and appropriate it to his own use. This dishonest experiment of Pallavicino was so gross, that his example as an irrigator was not followed at the time, nor indeed were many water-meadows formed in England till the end of the last or beginning of the present century. Since that time, many of them have been scientifically made both in England and in Scotland, which all have proved how profitably irrigation might be extended, and of which a few successful examples have been enumerated. As might be expected from the nature of the climates, irrigation is extensively practised in India, China, and parts of America, particularly Mexico and Peru; but as the irrigation of those countries presents no features peculiarly different from that related of Egypt and Italy, it is unnecessary to enlarge upon it.

VI. THEORY OF IRRIGATION.

The theory of irrigation, as propounded by the late Sir Humphrey Davy, is given by him in these words:—Water is absolutely essential to vegetation; and when land has been covered with water in the winter or in the beginning of spring, the moisture which has penetrated deep into the soil, and even the subsoil, becomes a sort of nourishment to the roots of the plants in the summer, and prevents those bad effects which often happen in lands in their natural state from a long continuance of dry weather. When the water used in irrigation has flowed over a calcareous country, it is generally found impregnated with carbonate of lime, and in this state it tends, in many instances, to ameliorate the soil. Common river water also generally contains a certain portion of organic matter, which is much greater after rains than at other times, and which exists in the largest quantity when the stream rises in a cultivated country. Even in cases where the water used for flooding is pure, and free from animal and vegetable substances, it acts by causing the more equable diffusion of nutritive matter existing in the land; and in very cold seasons it preserves the tender roots and leaves of the grass from being affected by frost. . . . In general, those waters which breed the best fish are the best fitted for watering meadows; but most of the benefits of irrigation may be derived from any kind of water. It is, however, a general principle, that waters containing ferruginous impregnations, though possessed of fertilizing effects, when applied to a calcareous soil, are injurious on soils that do not effervesce with acids; and that calcareous waters, which are known by the earthy deposite they afford when boiled, are of most use on siliceous soils, or other soils containing no remarkable quantity of carbonate of lime." To show the protective power of water against cold, it is only necessary to state the well-known physical fact, that water is of greater specific gravity at 42° Fahrenheit than at the freezing point of 32°; and hence water in contact with the roots of grass is rarely below 42°, a degree of temperature not at all prejudicial to the living organs of plants. These theories establish and indicate several advantages which are derivable from irrigation. It supplies moisture to the soil, necessary in dry seasons and in tropical countries; it affords protection to plants against the extremes of heat and cold; it disseminates manure most minutely to plants; and it washes away injurious matter from the roots of plants. The benefits derivable from irrigation are chiefly mechanical. The operation of water bringing matter into minute subdivision; the sediment which it contains when used in irrigation being minutely distributed around the stems of the plants; water protecting plants in irrigation against the extremes of heat and cold; by completely covering and embracing every stem and leaf; and the supplying of moisture to the soil, and washing poisonous matter out of it, are all purely mechanical operations. Warping is obviously a mechanical operation. Could the hand of man distribute manure around the roots and stems of grass as minutely and incessantly as turbid water; could it place a covering upon each blade and around each stem of grass, as completely as water can embrace each plant and keep it warm; could it water the grass as quietly and constantly as the slow current of irrigation; and could it wash away injurious matter from the soil as delicately around the fibres of the roots of grass as irrigating water, there would be no need of irrigation; the husbandman could then command at will verdant pasturage for his flocks and herds throughout the year, and in the driest season. His mechanical agency would be as effective as that of irrigation. But the relative powers of things being as at present constituted, man employs irrigation as the instrument of his will, and attains the maintenance of his live-stock by inducing Nature to assist him in a work in which she undoubtedly displays her superiority over him both in industry and dexterity.

(II. S., J. C.—ED.)

IRISH, a river of Siberia. See Siberia.