Part 70

The Hole in C must be something larger than in the Cut, because the Setting-screw must be so, being best to be of Brass, which is less apt to rust than Iron, of which Metal it was formerly made; but Brass, being weaker, requires the more of it to equal the Strength of Iron.

The Wreath, Fig. 14. is not necessary, because the Slider, Fig. 15. is sufficient without it; but then care must be taken, that the Edges of its Claws A B, which rub against the Cylinder of E, in Fig. 9. be taken off, to prevent their cutting it. This Slider is sometimes made of Brass, and sometimes of Iron.

Thus the Workman will have the Sides and Ends of the Turnep-mortise, which make the Whole of it, whereby he may make it exactly in soft Wood.

Fig. 7. called the inner Cylinder, being put into the Cylinder A, of the Steel Tongue, Fig. 4. whereby the Holes for the Axis of the Tongue, being the lower from the Top of the Mortise, do not only secure the Edges of the Mortise from breaking out, but also give room for the Flanches B, C, in Fig. 9. to be made to reach as far forwards as the Axis of the Tongue, and farther: Hereby the Hole, in the Bottom of the Hopper, may be as wide at the fore End, as at the pricked Line at the Letter B.

The Notches in the Spindle, Fig. 5. seem to appear deeper than is usual for Turnep-seed; but I remember I have drilled Furze-seed with a Turnep-drill without altering the Notches. As for the Shape of these Notches, they are so fully described in Fig. 6. and Fig. 8. of Plate 3. that I can add nothing to that Description; only that those being for the Wheat-drill, the Size of Notches for the Turnep-drill must be lesser in some proportion to the lesser Size of the Seed.

For making the Wheat-drill do the same as for the Turnep-drill. The Fig. 3. in Plate 2. is one Side of the Mortise, by which must be made Two in Pastboard. Fig. 10. in Plate 2. and Fig. 9. in Plate 3. are the Two Ends of it.

The Cover that prevents the Wheat from falling down on the hinder Side of the Spindle, is one intire Piece of Brass, which is marked B in Fig. 3. of Plate 3. but the Shape of it, with its Hole whereby it is held in by a Screw, is only seen in the Side, Fig. 3. of Plate 2. and there described by pricked Lines; and by pricking through them, the Shape of the End of the Cover may be taken, which Cover is of the same Shape from End to End.

The Joyner who cannot by these Additions, and the Explanations of the Plates, make these Drills in Wood, doth not deserve the Name of a Workman.

When he has once made them whole, he can easily make them in Halves like Fig. 8. in Plate 2.

By these Halves the Founder will make his Moulds proper for casting them in the best Brass. But in these Halves for Casting, there must be no other Holes, but the great Holes, and the Hole for the Setting-screw.

The great Hole in the Mould must be largest at E, in Fig. 9. Plate 2. and lesser in the Inside in Fig. 8. for as it must be of a conical Shape for making the Core, if it should be cast bigger within, when the Whitesmith bores it (as he must) to an exact Cylinder, the End E would be in Danger of bursting by the Force of the Boring, as it is much thinner than in the Mortise. And besides this, if there should be any little Flaw in the Edges of the Hole within the Mortise (which the Founder must avoid as much as possible), it may perhaps be bored out by means of the Hole’s being less there. The Hole must be something less in the Mould than its proper Size, even where it is largest; else it may happen, that in boring it to a true Cylinder it may become too big. And I believe, in the Cooling of the Brass, the Hole grows bigger as the Spindle grows less.

For the Hole of the Setting-screw, lay on upon the dark Part of Fig. 8. one of the Pastboard-sides; and from the black Line p q, draw a Line coincident to it as on the Brass, for making the half Hole A by; and the other Half of it on the opposite Half-side.

These Pastboards will be very useful to the Whitesmith, for directing him to find the Places where the Holes for the Axis of the Tongue, and those for screwing the Two Halves of the Mortise together, are to be made. I advise against boring the great Hole with a Tool (a Bit) with more than Four Edges; for it would be apt to tear the Brass.

The great Hole of the Turnep-drill is bored with Tools like those wherewith a Gun is bored. But the Wheat-drill is bored with a Screw-stock, whose Edges are made sharp for that Purpose, and may be set wider or narrower at Pleasure: It is put into the Hole along with an half-round Piece of Wood, the lower End of the Stock being set fast in a Vice: The whole Seed-box (for it must always be screwed together before it is bored), being put on the End of the Stock (made taper a little way for entering), is turned round it by a long wooden Spanner, which hath a Notch in the middle of it, to receive the whole Seed-box, in order to bore it by turning it round upon the Stock.

The Brass ought to be of the best Sort, which will be easy to file, and yet not mix with baser Metal.

The Seed-boxes may be cast whole by these Moulds; but I prefer those that are screwed together, for several Reasons, which I have not time now to write.

There is a Turnep Seed-box come to my Hands that was made by Pretenders; I wish it is the only one made in the same manner; for it is useless; the Notches in the Spindle are much shorter than the Breadth of the Mortise; at each End of the Notches is a deep Chanel (as deep as the Bottom of the Notches) quite round the Spindle, instead of a Mark, which should be but just visible for cutting the Notches; and instead of a tender Steel Spring, there is a strong Piece of Iron without Elasticity. By means of this Iron, the Machine grinds the Seed, instead of drilling it.

What I shall here add concerning the Wheat-drill, is some Alterations in Fig. 21. of Plate 4. viz. The fore Share and Sheat must be left out for drilling Wheat, up more middle Rows being used. And the Two Beams B B in the Plough, Fig. 1. must be set to make Chanels Ten Inches asunder. And the double Hopper, Fig. 15. must be set nearer together, so as the Seed may fall into the middle of the Funnels of the Beams.

Tho’ there is no Necessity of Marking-wheels for guiding the Drill-horse upon Ridges; yet they are very useful for holding the Drill steady, and to prevent its tottering, which without the Marking-wheels, and the fore Hopper, it is apt to do, when the Shares stand so near together as Ten Inches; and on a narrow Ridge one of the hinder Wheels might run off to the Furrow, and draw the Shares after it, if the Drill were not kept steady by the Marking-wheels, and by their Hopper, which takes hold of the single Standard by Fig. 22. as is seen in Fig. 21. in Plate 4. But there should not be so much room in it on each Side of the Standard, left the Plough by that means should have too much room to totter, now the Shares are so near together.

The Marking-wheels must be set at the Distance of the Breadth of Two Ridges, which, as we now make them, is about Nine Feet and an half from Wheel to Wheel.

The Brass Box may be taken out of the fore Hopper: And tho’ that Hopper be of no Use to the double Row, except as is abovesaid; yet if there should be Occasion to press the Marking-wheels deeper into the Ground for keeping the Plough the more steady in its Course, it may be usefully filled with Earth, or other Matter, sufficient for that Purpose. And besides, it may serve to plant Three Rows of St. Foin, when the fore Share and Sheat are put in, and the Beams and hinder Hopper set a Foot or Eighteen Inches wider, and the Marking-wheels at their due Distance, as is directed in the Essay. Thus the same Drill may plant Wheat and St. Foin.

A Drill for the double Rows might be made with a single hinder Hopper, instead of the double one. And there is a Contrivance to supply the Use of the fore Hopper for keeping the Plough steady, and more easy to make than that Hopper; but this cannot be described by Words without Cuts.

The Lime wherewith the brined Wheat is dried, receiving some of the Salts from the Brine, will stick in the Notches of the Spindle; yet never makes any Stoppage to their Delivery of the Seed; but every Year we clean the Notches from the Lime with a Chissel, and, if it were done oftener, it would not be amiss.

There is an Accident that may possibly happen, but never to a careful Driller; viz. a large Clod may some way be thrown into a Funnel of the Beam of the Plough, either by a Wheel, or by the Paddle that cleanses the Sheats from the Dirt that sticks to them when the Earth is wet. This may stop the Wheat from falling out of the Funnel into the Trunk; and then, so far as the Plough, goes thus stopped, the Chanel will have no Seed in it; but the Driller that follows may take it out immediately, which if he should neglect to do for never so little a Distance, he ought to stop the Plough whilst he supplies the Chanel with Seed from his Hand as far as it is empty. When there is any Danger of this, as in very rough cloddy Ground, it is best to take off the Drill-harrow, to the end that the Chanel may lie open for receiving the Seed from the Hand. But if the Ends of the Hopper reach below the Funnels, and they are otherwise defended, as they may be, this Accident can never happen.

When the Drill-harrow is taken off, the best way for taking up the Plough to turn it, is to bore a Hole of about half an Inch Diameter in the End of each Beam behind the Funnels, and fasten a Withe into these Holes; by which Withe the Driller very conveniently takes hold with one Hand, and lifts up the Plough, laying his other Hand on the Hopper to keep it steady. This Method of taking up the Plough hath been often used for the Wheat-drill, and for the Turnep-drill; and in the latter the Hole in the one Beam holds the Withe as well as do the Two Holes in the former.

There are new Editions of some of these Engines, which cannot be fully described without more Plates; but since those already described are found by Experience to be sufficient for the Purposes they were designed for, new Editions of them are not necessary, tho’ convenient in many respects.

Reason will easily make Additions to the Instruments when they are necessary; as when more than one Brass Spindle is to be turned by one or each Wheel for planting Clover amongst Barley after it is come up. ’Tis done by a very light Plough, drawn by a Man: It plants Four Rows at once Eight Inches asunder: The Shares are very short and narrow, and so are the Sheats and Trunks. ’Tis not difficult to put on a Crank at the other End of the Brass Spindle, in the same manner that the Handle that winds up a Jack is put on, and to fasten it at the Hole at I in Fig. 5. of Plate 2. This Crank must, at its first turning, before it turns up towards the Letter H, of the same Fig. be long enough to reach to within an Inch of the Fork of the Second Spindle. Thus each Wheel may turn several Spindles, and then this Drill may plant many Rows of Seeds at once.

When you plant Rows nearer together than Eight Inches, it is best that the Plough have Two Ranks of Shares and Hoppers, else the Earth may be driven before the Shares; but with Two Racks of them, they will not be more apt to drive the Earth before them in making Rows at Four Inches asunder, than at Eight, when there is only a single Rank of Shares.