In all Ploughs this first Coulter is, or ought to be, placed in the Beam in manner following; viz. its Back to bear against the Back of the Coulter-hole, its right Side above to bear against the upper Edge of the Coulter-hole, and its left Side to bear against the lower Edge of the Coulter-hole; so that always Three Wedges at least will be necessary to hold the Coulter; the Poll-wedge before it, as at i, in [Fig. 1.] another Wedge on the left Side of it above, and a Third on the right Side underneath: The Coulter-hole must be so made, that the Coulter standing thus across the Hole, its Point may incline so much towards the Left, as to be about Two Inches and an half farther to the Left[260] than the Point of the Share, if it were driven down as low as it; but it never ought to be so low in any Plough: As to its bearing forwards, the Point of the Coulter should never be before the Middle of the Point of the Share: What Angle the Coulter would make with the Bottom of the Share, may be seen by the Posture it stands in, in [Fig. 1.] If it should be set much more obliquely, it would have a greater Force to raise up the Poll-wedge, and get loose.
[260]I find that sometimes it is necessary in some of these Ploughs for the Point of this Coulter to stand yet farther on the Left of the Share’s Point.
The Three added Coulters should stand in the same Posture with this already described, in regard to the Inclination of their Points towards the Left: And this is a very great Advantage to them; for by this means, when the Fin is rais’d up, by turning the Handles towards the Left, their Points do not rise out of the Ground on the right Hand, as they would do without this described Inclination towards the Left; but in regard to their Pointing forwards, I find it best, that every one of the Three should be a little more perpendicular than that next behind it. So the Coulter 4 stands the nearest to Perpendicular of any of them. By this means there being more Room betwixt them above than below, they are the more easily freed from the Turf, whenever the Pieces, being covered with a great Quantity of Couch-grass, or the like, rise up betwixt them: which tho’ this seldom happens, makes a Necessity for a Man, or a Boy, to go on the Side with a forked Stick, to push out the Turf and Grass, which might otherwise fill the Spaces betwixt the Coulters, and raise up the Plough out of its Work.
’Tis to be observed, that none of these Coulters ought to descend so low as the Bottom of the Share, except when you plow very shallow: ’Tis always sufficient that they cut through the Turf, let the Plough go never so deep in the Ground.
It is necessary also, that when you plow very shallow, the Fin of the Share be broad enough to cut off the Fourth Piece or Furrow; else that, lying fast, will be apt to raise up the Ground-wrist, and throw out the Plough: But when you plow deep, the Ground-wrist will break off this Fourth Furrow, altho’ the Fin be not broad enough to reach it.
Sometimes the First or left Furrow is apt to come through betwixt the First Coulter and the Sheat, and so falls on the left-hand Side of the Plough: This is no Injury; but yet it is prevented, by letting the Second Coulter stand a little higher than the Third; and then the Second Furrow, holding the First at its Bottom, will carry it over, together with itself, on the right Side by the Earth-board; but yet never set this, or any of the Three added Coulters, so high that they may not cut through the Turf. But as for the first Coulter, tho’ it should cut but an Inch or Two within the Ground, the Share will break off the first Furrow in raising it up.
Remember, as often as the Point of any Coulter is worn too short, that you drive down the Coulter with a large Hammer, carried for that Purpose; and when it is driven low enough, fasten the Wedges again, so as to keep the Coulters in their right Postures, that their Incisions may be all of them equidistant.
[Fig. 18.] Is a Nut, with Two of its opposite Corners turn’d up, by which it is driven round by a Hammer, and has so great a Force, that Three of them, with their Screws properly placed, hold the Piece, [Fig. 16.] as fast to the Plough-beam, as if they both were made of one Piece of Wood; but as often as the Wood shrinks in dry Weather, the Nuts must be screw’d farther on, both here and in all other Places where they are used: particularly, those which hold up the Retch; for if the Sheat should once get loose, there is no Cure but by a new one.
Betwixt this Nut and the Wood, there should be a thin Iron Bolster, about the Thickness of a Shilling, broader than the Nut, to prevent the Nut from eating into the Wood, especially when it is to be often screw’d, as on the Retch of these Ploughs, and most of all on the Hoe-plough; but sometimes we use a Piece of Shoe-leather instead of an Iron Bolster.