or space from the share point to the junction or approach of the breast to the beamn: and that there is found a remarkable variation in the form of the breasts, or mould-boards of the ploughs throughout the northern parts of the same district, and which is chiefly in the degree of concavity or convexity. Some wheel-wrights and farmers prefer a form rather concave, a flatness in the fore part, which joins the share, and which gradually fills up as the sweep recedes; others like it neither concave nor convex; and there are many ploughs in which the convexity is extremely great. The great length of the breast, in some ploughs, is a circumstance which gives steadiness to the implements; but, at the same time, it is probably the means of increasing the draught to the horses in a great degree. The shortness of the breast, if the curve or sweep be in perfection, or wears equally every where, may lessen friction, and certainly does, if the earth be loose; but it probably may not have the same effect in the first earth, upon a stiff layer. It is, however, a pretty general opinion, that it lessens it in all cases. A great variety of breasts, of different forms and constructions, are represented in the plates upon ploughs, in the Agricultural Survey already referred to, which are well worth consulting by the enquirer.

The old Norfolk plough of our plate I. AGRICULTURE is held in much esteem in that, as well as some other light districts, as performing the work in an easy and expeditious manner. The carriage and wheels in all ploughs of this nature, however, form objections to them, and render them clumsy implements. The wheels added to them in our figure are an improvement.

The head and beam are short; the carriage part and wheels stand very high, of course the fore end of the beam is much elevated, by which advantage is gained in driving the horses, as it is usually drawn by two horses yoked abreast, the ploughman directing them by reins.

Of the swing sort, the Rotherham plough is perhaps the most popular. See AGRICUL TURE, plate I., figure 3. It is a light useful plough for all the less heavy sorts of soil, and has certainly much superiority where one plough is only required, and where the advantageous and economical method of performing the work with one man and two horses without a driver is used. It is in much estimation in all the West Riding of Yorkshire, and is said in the Agricultural Survey of the Riding district to have been invented by Mr. Joseph Foljambe, of Eastwood, about seventy years ago. In that district its usual dimensions are

And it has also a copse rack, or hock with teeth, to admit of more land being given to the plough, or the contrary, which is particularly useful in many cases.

It is noticed that with a few trifling alterations it is made use of over the whole district, and from that being often called the Dutch plough, it is supposed to have been originally brought from Holland by the inventor.

In Mr. Bailey's improved Rotherham plough the mould-board, which is of cast-iron, is so formed that the sod to be raised presses equally against it, in every part, from the sock point to the place where it leaves it; and it varies from other mould-boards, in not beginning to take its rise from the bottom of the heel, but at least twelve inches farther forward towards the sock, and in being cut away at the bottom opposite the heel, about three inches high, from the sole, by which the turning of the sod or furrow-slice is said to be much facilitated. Thus improved, these ploughs have been found to answer perfectly in different trials, and have been allowed by those who have seen them

at work to go with more ease to the teams than most others. It has been supposed that the beam, from its crooked form, which is obvious in some of its improvements, by being fixed so low down in the part next to the handles, makes the plough require less force, and to go in a more sliding manner. And that from the fore end of the beam being so much higher than the hinder part, the holder of the plough has more power, as the draught does not oppose so much resistance to him; for, if the beam were fixed to the handles much higher, as is usually the case in other ploughs, this plough would be constantly rippling on the point, and in that way increase the weight of draught. And where it meets with any resistance, such as a stone, it is liable to rise up, while in this form it proceeds in a sliding manner, which affords a steadier motion, and renders it more easily held. Besides, it is much stronger; particularly in the part where the left handle and the beam are joined, underneath the mortise where the tenon of the beam; by which the bearing of the ploughman on the handles does not in the least affect that part,

which in other ploughs is the weakest. In this improvement of the Rotherham, plough the mould-board is so constructed at the breast as to have a slight degree of convexity, instead of being concave, as is often the case, by which the furrow-slice is supposed to be prevented from slipping down; and by the keeping the lower part from the ground, when it comes to the turn of the breast, it falls off; consequently, as the furrow-slice is rested on or by the side of the breast, when the plough has advanced twelve inches the work is finished. By this improvement it is supposed that the plough will turn a furrow of any extent, from four to eighteen inches, where requisite, and the same in depth; as the plough that will produce a wide furrow and turn it well is capable of ploughing deep: the convexity of the breast also causes it to clean itself better, which is a desirable property, as it is thereby rendered less heavy, and less resistance afforded by one portion of earth being prevented from rubbing upon another, and at the same ime the work performed in a more perfect manner. The coulter has likewise a position so as to cut in a slanting manner, which causes any resistance to rise up more expeditiously, and the land to be opened with more facility than where it has a more perpendicular direction. Where this improved plough is employed with more than two horses abreast, the additional ones must be put before the pair, as it has not land enough to follow single horses.

Wheels have been added to these ploughs for particular purposes; and with either one or two fixed near the points of the beams, without any carriage parts, they have been found to pass through the soil in a very light, easy, and steady manner, and where there are two to require no holder in many cases, except in setting in turning out of the work at the ends of the ridges. The Northumberland or Cumberland plough is only an improved plough of this kind.

Small's chain plough is esteemed one of the best of the swing kind, and seems capable of very extensive application. It has its name from that of the inventor, who constructed it about forty years ago. It is neatly formed, and very light in its appearance, but at the same time, from the addition of the chain, possessing great strength. It is, therefore, capable of being employed in strong rough sorts of soil, where other sorts of ploughs are liable to be destroyed, as when the share, or even the coulter, in this implement, meets with any sudden impediment or obstructing cause, the stress is immediately thrown upon the chain instead of the beam. The sock is formed with a fin or feather, by which the firm earth in the bottom of the furrow is cut and moved more readily, and in a more complete manner than could be done by the sock in the common plough. In this plough the mouldboard is mostly made of cast-iron, having a gentle curve, by which the furrow-slice is thrown off with the least possible resistance. It is supposed by Mr. Donaldson to be on the whole one of the best constructed swing-ploughs for all sorts of soils. It is capable of ploughing, with one man and two horses yoked abreast without any driver, more than an acre a day with the

greatest ease. A plough of this sort is shown at fig. 1., plate II., RURAL ECONOMY.

Lord Somerville's single plough is also a plough of this sort, in which the throat is sharpened, and the mould board rendered moveable in the marner of his double furrow plough, shown in fig. 5 of plate AGRICULTURE. It is capable of being made use of with advantage in breaking up deep stiff soils, as from the moveable nature of the extreme part of the mould-board the furrow-slice can be laid more or less flat.

Ducket's skim-coulter, or trenching plough, is an implement of this sort, capable of being employed with great advantage where the surface is coarse or grassy. The principle upon which this plough operates is that of trenching ground in the practice of gardening, or depositing the surface spit of earth in the bottom of the preceding furrow, and placing the second, or that taken from below, upon it. Where the soils are sufficiently deep it is capable of performing its work to a considerable extent. It has been observed by lord Somerville, in a little tract on ploughs and oxen, that the skim requires a perpendicular direction, and that the coulter-hole should be removed farther from the throat and share, as in the common position it would choak when in work.

The use of the paring plough, the fourth figure of the plate AGRICULTURE, will be shown in that part of this article which treats of 'preparing' land on the arable system,

Plate I. RURAL ECONOMY, fig. 3, shows a plough to be made entirely of iron, to which a new kind of share is attached, the invention of Mr. Finlayson. This share, a, instead of having its cutting edge curved, or forming an obtuse angle with the land side, is made straight, and extending nearly the whole length of the mould-board, at an acute angle with the land side. At the back part of the share a triangular piece, or wing, b, is to be introduced occasional y by screwing its pin into a hole in the share, for the purpose of enabling it to turn and accommodate itself to the way of the plough. The intended purpose of this wing is to cut the clods of the earth, and break them in a perpendicular direction. In order to prevent the plough from choking at the coulter, the beam is made to curve upwards as seen at c, the coulter being introduced at the under side, and made fast by wedges. Another contrivance to effect the same object is shown at fig. 4, and consists in opening the beam by lateral curves, c, c, the coulter being attached by screw bolts, and rounded off at top. By these means, should any stubble or other vegetable matters accumulate in front, they would be enabled to rise over the top of the coulter without choking or obstructing the progress of the plough. For the purpose of regulating the depth at which the share shall cut the ground, the shackle by which the plough is drawn is to be shifted higher or lower, at the muzzle or nose of the beam. This is done by means of a screw, d, in fig. 3, which passes through the bolt of the shackle, and, by being turned, moves the shackle higher or lower, and thereby causes the share to be drawn through the ground at a less or greater depth beneath the surface, as circumstances may re