But when Two different Sorts of Seed are planted, suppose a Row of St. Foin betwixt every Row of Barley, the Rows of which being Eight Inches asunder, and the Barley drill’d by the fore Hopper into the Chanels made by the five Shares, and the St. Foin drill’d from the hinder Hopper into the Chanels made by Six Shares, the Marking-wheels must be at no greater Distance than those above-mention’d, where there are only Five Shares; because one of the Six, which are for the St. Foin, must always return in the same Chanel, going twice therein; for One Row of Barley would be missing, in case the parting Space should be made by this Sixth Share; and that parting Space would have no Barley in it. Therefore it is a Rule, that whensoever Two Sorts of Seeds are drill’d, the Rows of one Sort betwixt the Rows of the other there must be an odd Share in the Drill, which must go twice in one Chanel, and the Distance of the Marking-wheels must be accounted from that Rank of Shares which are the fewest: It must also be contriv’d in this Case, that each outermost Seed-box must deliver but half the Quantity of Seed that each of the inner Seed-boxes do; because the outer ones going twice in a Place, their Chanels would otherwise have a Quantity of Seed double to the rest.
In a Drill that has Two Spindles, we place the Marking-wheels on the foremost, which upon their Account is the longest; but if we should use the Wheels of the hinder Spindle as Marking-wheels, then that must be the longest, and so the fore Wheels (their Semidiameters being much longer than the Semidiameters of the hinder Wheels, and their Spindles shorter) would strike against the hinder Spindle, unless it were set farther back than is convenient.
When Ground is harrow’d the last time before it is to be drill’d, we contrive that the Harrows may not go directly towards the same Point that the Drill is to go, lest the Track of the Marking-wheel should be exactly parallel with the Track of the Harrow-tines, which might make it difficult to distinguish the Track of the Wheel from that of the Harrow-tine.
He that has not a great Quantity of Ground to plant with St. Foin, and does not plant it betwixt Rows of Corn, will have occasion for no other Drill than this Wheat-drill, describ’d in [Fig. 21.] He may plant his Rows at Fifteen Inches asunder, by the hinder Hopper, and its Shares, without removing them, the fore Hopper being taken off; or else you may plant Three Rows at Sixteen Inches asunder, by setting the Beams, and their Seed-boxes and Hoppers, at Thirty-two Inches asunder instead of Fifteen, equidistant from the fore Share: and then the Marking-wheels, which are those of the fore Spindle, must be Eight Feet asunder; to wit, double to the Spaces of the Three Shares, which are Three times Sixteen Inches (or Four Feet); or you may set the Two hinder Beams, &c. at what Distance you please, setting the Marking-wheels to correspond with them; but then the Harrow must be alter’d, and both its Legs and Tines must change their Places in the Head, the Legs for guiding it exactly, and the Tines to follow in all the Three Rows, which will require a third Tine to be added in the Middle, between the other Two. But without any other Alteration than that of taking off the fore Hopper, and that of lessening the Seed-passages of the hinder Hopper by the Setting-screws; my Man planted me several Acres of St. Foin with my Wheat-drill Two Years ago, the Rows being all Fourteen Inches asunder: It is now an extraordinary good Crop.
In case the Shares, being only Three, should in fine Ground go so deep as to endanger the Burying of the Seed, the best Remedy to prevent this fatal Misfortune is, to place a triangular Piece of Wood, like those in [Figures 25. and 26.] the first of which shews one Side thereof, with the Nail by which it is to be nail’d into the lower Part of the Trunk, with, its most acute Angle uppermost; the other in [Fig. 26.] shews the same, and its Back-side a b, that is to be nail’d to the Back of the Shear, being of the same Breadth with it; its Bottom b c being the Breadth of the Plates, on their Inside, the Angle c coming out backwards, just as far as the Plates: The Depth of this Piece from a to c is uncertain, because the Plates of some Trunks are broader than of others. The Use of this Piece is, to fill up the lower Part of the Trunk; so that the Seed, dropping upon the oblique Side of this Piece of Wood, may by it be turn’d into the Chanel, after so much Mould is fallen in it, as will sufficiently lessen its Depth, whereby the Danger of burying the Seed is avoided: And such a Piece of Wood placed into each Trunk, I think, is preferable to Ground-wrists, which are commonly used for this Purpose; because the Ground-wrists leave the Chanels too wide and open.
But when only the Two hinder Sheats are used for St. Foin, we can make their Chanels the shallower, by sinking the Limbers by their Chain, so much as that, the Plough bearing most upon the fore Share, the hinder Shares will go the shallower.
When we drill hilly Ground, both up and down, we cover the hinder Parts of all the Trunks, from their Tops, to within Two or Three Inches of the Ground, to prevent the Seed’s falling out far behind the Trunk, in going up Hill; and this we do either by a Piece of Leather nail’d to each Side of a Sheat, the Middle of the Leather bearing against the hinder Part of the Plates (or Trunk); or sometimes, instead of Leather, we use Tin.
Every Trunk being thus inclos’d behind, we can drill up and down an hill of a moderate Ascent; but when it is very steep, we never drill any thing but St. Foin on it, and that by a Drill made for the Purpose, so very light, that a Man may carry it up the Hill on his Back, and draw it down after him: This Drill has Five or Six Sheats in one Row (with the Harrow behind them). Their Shares being extremely short, the Standards which draw the Hopper must be set perpendicular to the Horizon, when the Drill is coming down, rather than to the Surface of the Side of the Hill: The Funnels must also correspond with the Standards.
Some, instead of these Sheats, make use of hollow wooden Harrow-tines, thro’ which the Seed descends: But these I do not approve of; because where the Ground is hard, and not fine, they rise up, and make no Chanels for the Seed; and then it lying uncover’d will be malted.