Part 55

CHAP. XIX.

The Description of a Four-coulter’d Plough.

To describe all Parts of a Plough geometrically, would require more Time and Learning than I am Master of: Therefore leaving that to be done by somebody else, who is better qualified for it, I shall at present attempt little more than what relates to the Three added Coulters.

In Plate I. Fig. I. is the Portrait of a common Two-wheel’d Plough used in Berkshire, Hampshire, Oxfordshire, and Wiltshire, and in most other Countries of South-Britain; and is generally esteemed the best Plough for all Sorts of Land, except such miry Clays that stick to the Wheels, and clog them up, so as they cannot turn round.

But they have, in some Places, a Contrivance to prevent this Inconvenience; which is done by winding Thumb-ropes of Straw about the Iron Circles of the Wheels, and about the Spokes. The Wheels pressing against the Ground, the Thumb-ropes are distended on each Side: which Motion throws off the Dirt, and prevents its sticking to the Wheels, which it would otherwise do.

’Tis commonly divided into Two Parts; viz. the Plough-head, and the Plough-tail.

The Plough-head contains the Two Wheels A, B, and their Axis or Spindle of Iron passing thro’ the Box C, turning round both therein, and in the Wheels; the Two Crow-staves D, D, fastened into the Box perpendicularly, and having in each Two Rows of Holes, whereby to raise or sink the Beam, by pinning up or down, the Pillow E, to increase or diminish the Depth of the Furrow; the Gallows F, thro’ which the Crow-staves pass at top, by Mortises, into which they are pinned; G the Wilds with its Links and Crooks of Iron, whereby the whole Plough is drawn; H the Two-chain, which fastens the Plough-tail to the Plough-head, by the Collar I at one End, and by the other End passing thro’ a Hole in the Middle of the Box, is pinned in by the Stake K; L the Bridle-chain, one End whereof is fastened to the Beam by a Pin, and the other End to the Top of the Stake, which Stake is held up to the left Crow-staff, by the With M, patting round it above, and under the End of the Gallows below; or instead of this With, by a Piece of Cord, and sometimes by the End of the Bridle-chain, when that is long enough.

The Plough-tail consists of the Beam N: the Coulter O; the Share P; and the Sheat Q; the Hinder-sheat R, passing thro’ the Beam near its End; S the short Handle, fastened to the Top of the Hinder-sheat by a Pin, and to the Top of the Sheat by another Pin; T the Drock which belongs to the right Side of the Plough-tail, and whereto the Ground-wrist V is fasten’d; as is the Earth-board, whose Fore-part W is seen before the Sheat; and also the long Handle X, whose Fore-part Y appears before the Sheat, and is fasten’d to the Drock by a Pin at a, the other End of which Pin goes into the Beam. Z is the double Retch, which holds up the Sheat, and passes through the Beam to be fasten’d by its Screws and Nuts at b and c.

But without intrenching much farther upon the common Plough-wright’s Art, whose Trade is his Living, I’ll hasten to shew the necessary Difference there is betwixt the common Plough, and the Four-coulter Plough, beginning with Fig. 2. where it is represented as standing upon a level Surface.

Fig. 2. And, First, The Beam differs in Length, being Ten Feet Four Inches long, as the other Plough-beam is but Eight Feet; it differs in Shape, as the other is strait from one End to the other, but this is strait only from a to b, and thence turns up of a sudden, in the manner that is shewn in the Cut; so that a Line let down perpendicular, from the Corner at a, to the even Surface whereon the Plough stands, would be Eleven Inches and an half, which is its Height in that Place; and, if another Line were let down, from the turning of the Beam at b, to the same Surface, it would be One Foot Eight Inches and an half, which is the Height that the Beam stands from the Ground, at that Part; and a Third Line let down to the Surface, from the Bottom of the Beam, at that Part which bears upon the Pillow, will shew the Beam to be Two Feet Ten Inches high above the Surface in that Part.

From the End a, to the Back-part of the first Coulter, is Three Feet Two Inches; from thence, to the Back of the next Coulter, is Thirteen Inches; thence to the Third, Thirteen Inches; and from thence to the Fourth, the same. From a to b is Seven Feet.

This Crookedness of the Beam is to avoid the too great Length of the foremost Coulters, which would be necessary if the Beam was strait; and then, unless they were vastly thick and heavy, they would be apt to bend, and the Point of the Fourth would be at so great a Distance from its Coulter-hole, that it would have the greater Power to loosen the Wedges, whereby the Coulter would rise up out of its Work, as it never doth when the Beam is made in this bending Manner. This Beam is made either of Ash, which is the lightest, or of Oak, which is the most durable. Its Depth and Breadth may vary, according to the heavier or lighter Soil it is to till; but this before us is in Depth Five Inches at the first Coulter-hole, and in Breadth Four Inches.

Fig. 4. Is the Sheat Q in Fig. 1. (broad Seven Inches) with the Iron Retch on it, the left Leg of which Retch must stand foremost, to the end that the Edge of its Fore-part, that is flat, may fit close to the Wood of the Sheat: This Retch holds the Sheat fast up to the Beam by its Nuts and Screws; as also doth a Pin driven into the Hole a, which Hole being a small Part of it within the Beam, the Pin being driven into the Hole, draws up the Sheat very tight to the Beam. The principal thing to be taken notice of here, is the Angle b c d, which shews the Elevation of the Sheat; the Line c d is supposed to be equal with the Bottom of the Share (or rather with the plain Surface whereon it stands); when this Angle at c is larger than of Forty-five Degrees, a common Plough never goes well: In my Four-coulter Plough I choose to have it of Forty-two or Forty-three at the most.

Fig. 5. Is the Share; a is the End of the Point; b is the Tail of the Share, long from a to b Three Feet Nine Inches; c the Fin; d the Socket, into which the Bottom of the Sheat enters; e a thin Plate of Iron riveted to the Tail of the Share: By this Plate, the Tail of the Share is held to the hinder Sheat, as at d in Fig. 1. by a small Iron Pin with a Screw at its End, and a Nut screw’d on it on the inner or right Side of that Sheat. From a to f is the Point, long about Three Inches and an half, flat underneath, and round at Top: It should be of hard Steel underneath. From f to c is the Edge of the Fin, which should be well steeled; the Length of it is uncertain, but it should never make a less Angle at f than it appears to make in this Fig. The Socket is a Mortise of about a Foot long, at the upper Part, Two Inches deep: The Fore-end of this Mortise must not be perpendicular, but oblique, conformable to the Fore-part of the Sheat which enters it; the upper Edge of which Fore-part must always bear against the Sheat at e in Fig. 4. but if this End of the Socket should not be quite so oblique as the Sheat, it may be help’d, by taking off a little of the Wood at the Point c.

Fig. 6. Shews the Share, with its right Side upwards, in the same Posture as when it plows; whose Side a b should be perfectly strait, but its under Side at c, which is its Neck, should be a little hollow from the Ground, but never more than half an Inch in any Plough, and a Quarter of an Inch in a Four-coulter Plough; so that the Share, when it is first made, standing upon its Bottom, bears upon the level Surface only in Three Places; viz. at the very Point a, at the Tail b, and at the Corner of the Fin d.

Fig. 7. Is the Share, turn’d Bottom upwards; and shews the Concavity of the Fin at a; which must be greatest in a stony rubbly Soil.

Fig. 8. Shews the Share, the right Side upwards, but leaning towards the Left.

In placing of the Share rightly upon the Sheat, consists the well going of a Plough, and is the most difficult Part of a Plough-wright’s Trade, and is very difficult to be shewn. Supposing the Axis of the strait Beam, and the left Side of the Share, to be both horizontal, they must never be parallel to each other; for if they were, the Tail of the Share, bearing against the Side of the Trench, as much as the Point, would cause the Point to incline to the right Hand, and go out of the Ground into the Furrow. If the Point of the Share should be set, so that its Side should make an Angle on the right Side of the Axis of the Beam, this Inconvenience would be much greater; and if its Point should incline much to the Left, and make too large an Angle on that Side with the Axis of the Beam, the Plough would run quite to the left Hand; and if the Holder, to prevent its running out of the Ground, turns the upper Part of his Plough towards the left Hand, the Fin of the Share will rise up, and cut the Furrow diagonally, leaving it half unplow’d; beside, the Plough will rise up at the Tail, and go all upon the Point of the Share: To avoid these Inconveniences, the strait Side of the Share must make an Angle on the left Side of the Beam, but so very acute, that the Tail of the Share may only press less against the Side of the Trench than the Point does. This Angle is shewn by the prick’d Lines at the Bottom of Fig. 1. where the prick’d Line e f is supposed to be the Axis of the Beam let down to the Surface, and the prick’d Line g f parallel to the left Side of the Share; but this Angle will vary as those Two prick’d Lines are produc’d forwards to the Fore-end of a long and a short Beam, keeping the same Subtense: For Plough-wrights always take this Subtense at the Fore-end of a Beam, whether it be a long Beam or short one; and it is the Subtense e g, that determines the Inclination the Point of the Share must have toward the left Hand. Plough-wrights differ much in this Matter; but, by what I can learn by those that make the Ploughs I see perform the best, this Subtense at the Fore-end of an Eight-feet Beam should never be more than one Inch and an half; and by full Experience I find, that whether the Beam be long or short, the Subtense must be the same; for when my Plough-wrights take this Subtense at Eight Feet from the Tail, when they make my Four-coulter Plough, whose Beam is Ten Feet Four Inches long, the Point of the Share will incline too much to the Left, and it will not go well until this Fault be mended, by taking the same Subtense quite at the End of the Beam; which makes the mentioned Angle more acute.

This is the greatest Misfortune incident to a common Two-wheeled Plough, and happens generally by the Fault of the Maker, though sometimes by the Plowman’s setting it so, that the Point of the Share turns too much to the Left. I have seen Land plowed in this manner, where not half of it has been moved, nor better tilled than by Raftering, not only cut diagonally, but also half the Surface hath remained whole, where when the Earth that was thrown on it was removed, the Weeds appeared unhurt on the unplowed Surface. In this Case, they for a Remedy let the Plough to go deeper; and then, if it go deep enough for the Fin to cut off the Furrow at a just Depth, the Point will go below the Staple, which may ruin the Soil, unless it be very deep.

When our English Ploughs go in this manner, they make much worse Work than the Eastern Ploughs, that have no Coulter; for these, contrary to ours, though they always cut their Furrow diagonally, cut it thin on that Side from which it is turned, as our bad Ploughs leave it thin on that Side towards which it is turned. The Earth the Easterns leave by their Diagonal in one Furrow, is taken off by the next; but ours leaving Part of their Furrow behind them, on the Side next to the plowed Part of the Field, come at it no more; but the other can plow cleaner, their Diagonal being contrary to ours, which leaves the Trench deepest on the Side next to the unplowed Part of the Field; but unless the Fin of the Four-coultered Plough go parallel to the Surface of the Earth, it will not plough at all; or will leave Two or Three of its Four Furrows untouched.

Fig. 3. Shews the right-hand Side, and upper Side of the Four-coulter Plough, of which V the Iron Ground-wrist is shewn in Fig. 9. long Two Feet Five Inches, deep at the End b Four Inches, and Three-eighths of an Inch thick, except at the End a, where it is thin enough to bend, so as to fit close to the Share, as at e, in Fig. 6. The Ground-wrist has Four small Holes near its End a, into one of which goes a Nail, to fasten it to the Shear, thro’ the long Hole in the Side of the Socket of the Share, as at a, in Fig. 10. and then it will stand in the Posture shewn by e f, in Fig. 6. From the Outside of the Ground-wrist at f, to the Outside of the Share at b, is Eleven Inches and an half, which is the Width of the lower Part of the Plough-tail at the Ground; the Ground-wrist has several Holes at the upper Side of its broadest End, as at b, in Fig. 9. by which it is nailed to the lower Part of the Drock T, as in Fig. 3. which Drock with its Perforations is shewn in Fig. 11.

Fig. 12. Is the Earth-board, with its Inside upwards; the Notch a b shews the Rising of the Wood, which takes hold of the Edge of the Sheat, to hold it the firmer, to which it is fastened by the Holes c and d; and at the other End it is fastened to the Drock, at the Hole e. All which is seen as it stands mark’d with W, in Fig. 3. But this Pin, with which it is fastened to the Drock, is bigger in the Middle than at each End; which prevents the Earth-board from coming near the Drock: By this Pin, the Earth-board is set at a greater or less Distance from the Drock, as there is Occasion to throw off the Furrow farther from the Plough at some times than at others: It always stands considerably farther out on the right Hand than the Ground-wrist does, which is one Reason that the Drock is made crooked, bending outwards in that Part.

The long Handle X is Fig. 13. long Five Feet Four Inches, broad in the widest Part Four Inches, pinned to the Sheat thro’ the Holes a b, and pinned to the Drock through the Hole c.

The short Handle S is Fig. 14. and is long Three Feet Nine Inches, pinned to the hinder Sheat (being Fig. 15.) by the Hole a, and to the Top of the Fore-sheat above the Beam by the Hole b.

The Handles are made so long, for the more easy guiding of the Plough; but the lazy Ploughman is apt to cut them off shorter, close up to the Plough, to the end that, bearing his whole Weight thereon, he may in a manner ride instead of walking; but if he should thus ride on long Handles, he would tilt up the Fore-end of the Beam, and raise the Share out of the Ground.

The chief, and most indispensably necessary thing to be observed, is, to place the Four Coulters in such a manner, that the Four imaginary Planes described by the Edges of the Four Coulters, as the Plough moves forwards, be all of them parallel to each other, or very nearly so; for if any one of them should be much inclined to, or recede from, either of the other three, they could not enter the Ground together. In order to place them thus, the Coulter-holes must be made through the Beam, in the manner as they are shewn in Fig. 3. viz. the Second Coulter-hole is Two Inches and an half more on the Right than the First, the Third, Two and an half more on the right Hand than the Second, and the Fourth, Two Inches and an half more on the right Hand than the Third, conformable to the Four Incisions or Cuts they are to make in a Ten-inch Furrow: And because no single Beam is broad enough to hold the Four Coulter-holes at this Distance, we are forced to add the Piece shewn in Fig. 16. The Second Hole is made Part in the Beam, and Part in this Piece; the Third and Fourth are made wholly in this Piece, in which a, b, c, are the Ends of the Three Screws, which fasten the Piece to the right Side of the Beam by their Nuts.

The Distance of Two Inches and an half, by which each of the Three added Coulters stand more to the right Hand than that immediately behind it, must be reckoned from the Middle of one Hole to the Middle of the other.

The Fore-part of every Hole must incline a little towards the Left; so that the Backs of the Coulters may not bear against the left Side of the Incisions made by the Edges.