purpose of levelling, which go across the old ridges, as broad as possible; because the deep trench that is thus made in each of the furrows is an impediment in the future operations, as well as the height that is accumulated in the middle of each of these ridges; so that the fewer there are of these the better. The farmer, therefore, will do well to advert to this, and begin by forming a ridge by always turning the plough to the right hand, till it becomes of such breadth as makes it very inconvenient to turn longer in that manner; and then, at the distance of twice the breadth of this new-formed ridge from the middle of it, mark off a furrow for the middle of another ridge, turning round it to the right hand, till it becomes of the same breadth, and then, turning to the left hand, plough out the interval that was left between the two newformed ridges. By this mode of ploughing, each ridge may be made of forty, or fifty, or sixty yards in breadth, without any great inconvenience; for, although some time will be lost in turning at the ends of these broad ridges, yet, as this operation is only to be once performed in this manner, the advantage that is reaped by having few open furrows is more than sufficient to coun terbalance it. To moderate the height that would be formed in the middle of each of these grea ridges, it will be proper to mark out the ridges, and draw the furrow that is to be the middle of each some days before you collect your laborers to level the field, that you may, without any hurry or loss of labor, clear out a good trench through the middle of each of the old ridges; as the plough at this time, going and returning nearly in the same track, prevents the laborers from working properly without this precaution. If these rules are attended to, your field will be at once reduced to a proper level, and the rich earth that formed the surface of the old ridge be still kept upon the surface of your field; so that the only loss that the possessor of such ground can sustain by this operation is merely the expense of performing it.'

Dr. Anderson afterwards makes a calculation of the different expenses of levelling by the plough and by the spade, in which he finds the latter by far the cheapest method. It should be a rule, according to him, to direct the ridges north and south if the ground will permit. In this direction, the east and west sides of the ridges, dividing the sun equally between them, will ripen at the same time. It is a great advantage to form ridges so narrow and so low as to admit the crowns and furrows to be changed alternately every crop. The soil nearest the surface is the best; and, by such ploughing, it is always kept near the surface, and never buried. In high ridges the soil is accumulated at the crown, and the furrows left bare. Such alteration of crown and furrow is easy, where the ridges are only seven or eight feet broad. This mode of ploughing answers perfectly well in sandy and gravelly soils, and even in loam; but it is not safe in clay soil. In that soil the ridges ought to be twelve feet wide, and twenty inches high; to be preserved always in the same form by casting, that is, by ploughing two ridges to gether, beginning at the furrow that separates VOL. XIX.

them, and plougning round and round till the two ridges be finished. By this method, the separating furrow is raised a little higher than the furrows that bound the two ridges. But at the next ploughing that inequality is corrected, by beginning at the bounding furrows, and going round and round till the ploughing of the two ridges be completed at the separating furrow.

For cleaning the ground of weeds, a cleaning harrow is often used. It is drawn by a single horse, directed by reins, which the man at the opposite corner puts over his head, to have both hands free. In this corner is fixed a rope, with which the man from time to time raises the harrow from the ground, to let the weeds drop. For the sake of expedition, the weeds ought to be dropped in a straight line cross the field, whether the harrow be full or not; and seldom is a field so dirty but that the harrow may go thirty yards before the teeth are filled. The weeds will be thus laid in parallel rows, like those of hay raked 'together for drying. A harrow may be drawn swiftly along the rows, to shake out all the dust; and then the weeds may be carried clean off the field in carts. But, instead of burning them, they may be converted into useful manure, by laying them in a heap, with a mixture of hot dung to begin fermentation. way of cleaning land will appear operose; but neither the labor nor expense is immoderate. At any rate, these ought not to be grudged; for, if a fieid be once thoroughly cleaned, the seasons must be very cross, or the farmer very indolent, to make it necessary to renew the operation in less than twenty years. In the worst seasons a few years' pasture is always under command; which effectually destroys triennial plants, such as thistles and couch-grass.

At first view, this

3. We may here offer a few remarks of a practical kind on soils:-i. Clay is in general the stiffest of all soils, and contains an unctuous quality. See CLAY. But, under the term clays, earths of different sorts and colors are included. One kind is so obstinate that scarcely any thing will subdue it; another is so hungry and poor that it absorbs whatever is applied, and turns it into its own quality. Some clays are fatter than others, and the fattest are the best; some are more soft and slippery. But all of them retain water poured on their surfaces, where it stagnates, and chills the plants, without sinking into the soil. The closeness of clay prevents the roots and fibres of plants from spreading in search of nourishment. The blue, the red, and the white clay, if strong, are unfavorable to vegetation. The stony and looser sort are less so; but none of them are worth any thing till their texture is so loosened by a mixture of other substances, and opened, as to admit the influence of the sun, the air, and frost. Among the manures recommended for clay, sand is of all others to be preferred: and sea-sand the best of all, as it most effectually breaks the cohesion. It is preferred, because it is not formed wholly of small stones; but contains a great deal of calcareous matter, such as, shells grated and broken to pieces by the tide; and al so salts. The smaller the sand is the more easily it penetrates the clay; but it abides less time in it than the larger The next best

H

Shallow ploughing ought always to be adopted after turnips are eaten on the ground, that the manure may not be buried too deep; and also in covering lime,-especially if the ground has been pulverised by fallowing, because it naturally tends to sink in the soil. In ploughing down farm-yard dung, it is commonly necessary to go rather deep, that no part of the manure may be left exposed to the atmosphere. In the first ploughing, for fallows or green crops, it is advisable to work as deep as possible, and no great danger is to be apprehended, though a small portion of the subsoil be at that time brought to the surface. The furrow-slices are generally distributed into beds varying in breadth according to circumstances; these are called ridges or lands, and are divided from one another by gutters or open furrows. These last serve as guides to the hand and eye of the sower to the reapers, and also for the application of manures in a regular manner. In soils of a strong or retentive nature, or which have wet close subsoils, these furrows serve likewise as drains for carrying off the surface water, and being cleared out, after the land is sown and harrowed, have the name of water furrows.

'Ridges are not only different in breadth, but are raised more or less in the middle, on different soils. On clayey retentive soils, the great point to be attended to is the discharge of superfluous water. But narrow ridges or stitches, of from three to five feet, are not approved of in some of the best cultivated counties. In these a breadth of fifteen or eighteen feet, the land raised by two gatherings of the plough, is most commonly adopted for such soils; such ridges being thought more convenient for manuring, sowing, harrowing, and reaping than narrower ones; and the water is drained off quite as effectually. Ridges on dry porous turnip soils may be formed much broader; and, were it not for their use in directing the laborers, may be, and sometimes are, dispensed with altogether. They are often thirty, or thirty-six feet broad, which in Scotland are called band-win ridges, because reaped by a band of shearers, commonly six, served by one binder. If it be wished to obliterate the intermediate furrows, this may be done by casting up a narrow ridglet or single bout-drill between the broad ridges, which is afterwards ievelled by the harrows.

The mode of forming ridges straight and of uniform breadth is as follows:-Let us suppose a field perfectly level that is intended to be laid off into ridges of any determinate breadth. The best ploughman belonging to the farm conducts the operation, with the aid of three or more poles shod with iron, in the following manner :The first thing is to mark off the head ridges, on which the horses turn in ploughing, which should in general be of an equal breadth from the bounding lines of the field, if these lines are not very crooked or irregular. The next operation, assuming one straight side of the field, or a line that has been made straight, as the proper direction of the ridges, is to measure off from it with one of the poles (all of them of a certain length, or expressing specific measures), half the intended breadth of the ridge, if it is to

be gathered, or one breadth and a half if to be ploughed flat; and there the ploughman sets up a pole as a direction for the plough to enter. On a line with this, and at some distance, he plants a second pole, and then in the same manner a third, fourth, &c., as the irregularity of the surface may render necessary, though three must always be employed, the last of them at the end of the intended ridge, and the whole in one straight line. He then enters the plough at the first pole, keeping the line of poles exactly between his horses, and ploughs down all the poles successively; halting his horses at each, and replacing it at so many feet distant as the ridges are to be broad; so that, when he reaches the end of the ridge, all his poles are again set up in a new line parallel to the first. He returns, however, along his former track, correcting any deviations, and throwing a shallow furrow on the side opposite to his former one. These furrows, when reversed, form the crown of the ridge, and direct the ploughmen who are to follow. The same operations are carried on until the whole field is marked out. This is called feiring in Scotland, and striking the furrows in England. It is surprising with what accuracy these lines are drawn by skilful ploughmen. Another method has been adopted for the same purpose, which promises to be useful with less experienced workmen. A stout lath or pole, exactly equal in length to the breadth of the intended ridge, is fixed to the plough at right angles to the line of the draught, one end of which is placed across the handles exactly opposite the coulter, while the other end projects towards the left hand of the ploughman, and is preserved in its place by a rope passing from it to the collar of the near-side horse. At the outer end of the lath a coulter or harrow tine is fixed perpendicularly, which makes a trace or mark on the ground, as the plough moves onwards, exactly parallel to the line of draught. By this device, when the plough is feiring the crown of one ridge, the marker traces the line on which the next ridge is to be feired.-General Report of Scotland, vol. i. p. 354.

The direction and length of ridges are points which must evidently be regulated by the nature of the surface, and the size of the field. Short angular ridges, called butts, which are often necessary in a field with irregular boundaries, are always attended with a considerable loss of time, and ought to be avoided as much as possible. In ploughing steep land it is thought advisable to give the ridges an inclination towards the right hand at the top, by which, in going up the acclivity, the furrow falls more readily from the plough, and with less fatigue to the horses. Another advantage of forming ridges in a slanting direction, on such lands, is that the soil is not so apt to be washed down from the higher ground, as if the ridges were laid at right angles. Wherever circumstances will permit, the best direction, however, is due north and south, by which the grain on both sides of the ridge enjoys nearly equal advantages from the influence of the sun.

'Land thus formed into ridges,' says Mr. Loudon, is afterwards cultivated without mark

ing out the ridges anew, until the inter-furrows have been obliterated by a fallow or fallow crop. This is done by one or other of the following modes of ploughing. 1. If the soil be dry, and the land has been ploughed flat, the ridges are split out in such a way that the space which the crown of the old ridge occupied is now allotted to the open furrow between the new ones. This is technically called crown and furrow ploughing. 2. When the soil is naturally rather wet, or, if the ridges have been raised a little by former ploughings, the form of the old ridges, and the situation of the inter-furrows, are preserved by what is called casting, that is, the furrows of each ridge are all laid in one direction, while those of the next adjoining ridges are turned the contrary way; two ridges being always ploughed together. 3. It is commonly necessary to raise the ridges, on soils very tenacious of moisture, by what is called gathering, which is done by the plough going round the ridge, beginning at the crown, and raising all the furrow slices inwards. 4. This last operation, when it is wished to give the land a level surface, as in fallowing, is reversed by turning all the furrow-slices outwards; beginning at the inter-furrows, and leaving an open furrow on the crown of each ridge. In order to bring the land into as level a state as possible, the same mode of ploughing, or cleaning, as it is called, may be repeated as often as necessary. With respect to ploughing relatively to time, in the strongest lands, a pair of good horses ought to plough three-quarters of an acre in nine hours; but upon the same land, after the first ploughing, on friable soils, one acre or an acre and a quarter is a common day's work. Throughout the year, an acre a day may be considered as a full average on soils of a medium consistency. The whole series of furrows on an English statute acre, supposing each to be nine inches broad, would extend to 19,360 yards; and adding twelve yards to every 220, for the ground travelled over in turning, the whole work of one acre may be estimated as extending to 20,416 yards, or eleven miles and nearly five furlongs.

In ploughing relatively to season, it is well known that clayey or tenacious soils should never be ploughed when wet; and that it is almost equally improper to allow them to become too dry, especially if a crop is to be sown without a second ploughing. The state in which such lands should be ploughed is that which is commonly indicated by the phrase, between the wet and the dry,'-while the ground is slightly moist, mellow, and the least cohesive. The season best for ploughing the first time, for fallow or green crops, is immediately after harvest, or after wheat sowing is finished; and, when this land has been gone over, the old tough swards, if there be any, are next turned up. The reasons for ploughing so early are sufficiently obvious; as the frosts of winter render the soil more friable for the spring operations, and assist in destroying the weed roots. In some places, however, the first ploughing for fallow is still delayed till after the spring seed-time.'

The cultivator, grubber, scuffler, scarifier, &c., are used to lessen the number of ploughings in

fallows or light free soils. Their operation differs from that of the plough in not reversing the surface, and therefore they can never, as some suppose, become a substitute for that implement. Still the grubber is recommended by good judges as a valuable implement. Lester of Northampton, who is said first to have invented an implement of this kind, declares himself confident that one man, a boy, and six horses, will move as much land in a day, and as effectually, as six ploughs: meaning land in a fallow state that has been previously ploughed. And this may allow us to introduce the important question

5. Of Fallowing. The vague ancient opinion of the use of nitre, and of nitrous salts in vegetation,' says Sir Humphrey Davy, 'seems to have been one of the principal speculative reasons for the defence of summer fallows. Nitrous salts are produced during the exposure of soils containing vegetable and animal remains, and in greatest abundance in hot weather; but it is probably by the combination of the azote from these remains with oxygen in the atmosphere that the acid is formed; and at the expense of an element which otherwise would have formed ammonia; the compounds of which are much more efficacious than the nitrous compounds in assisting vegetation. Mr. Loudon observes that this reason is, however, more speculative than experimental, and seems influenced by the opinion adopted by the author, that fallows are of little use in husbandry. One obvious advantage of aeration in summer, or a summer fallow,' he says, 'is, that the soil may thus be heated by the sun to a degree which it never could be, if partially covered with the foliage of even the widest drilled crops. For this purpose, if the soil is laid up in large lumps, it is evident it will receive more heat by exposing a greater surface to the atmosphere, and it will retain this heat longer than can be expected, from the circumstance of the lumps reflecting back the rays of heat radiated by each other.' A clayey soil in this way (Farmer's Magazine, 1815) may be heated to 120°, which may in some degree alter its absorbent powers as to water, and contribute materially to the destruction of vegetable fibre, insects, and their eggs. By the aeration of lands, in winter, minute mechanical division is obtained by the freezing of the water in the soil; for, as water in the solid state occupies more space than when fluid, the particles of earthy matters and of decomposing stones are thus rent asunder, and crumble down in a fine mould. Rough stony soils will thus receive an accession to their finer soil every winter.

Agricultural experience,' adds our author, has fully proved that fallows are the only means by which stiff clays in moist climates can be effectually cleared of weeds. Supposing therefore that no other advantage whatever was obtained, that no nutritive matter was imbibed from the atmosphere, and the soil was neither chemically nor mechanically benefited by aeration, this benefit alone, the effectual eradication of weeds, is sufficient to justify the use of fallows on such soils. Many of the objections to fal