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.