When a Drill has only one Rank of Shares, we screw on the Harrow by its Legs, to the Inside of the Two outside Sheats, as near as we can to their fore Shoulders, leaving sufficient room for the Harrow to rise and sink, in the same manner as when it is drawn by the Beams. [Illustration: _Plate IV_ _Page. 378_ _B. Cole Sculps._] CHAP. XXII. _Of the Turnep-Drill._ _Plate_ 5. shews the whole Mounting of a Turnep-drill. _Fig._ 1. is a Plough, but little differing from the Drill-plough last mentioned. A, A, are the Two Limbers, differing in nothing from the other, except that they are lighter, not being above Two Inches Diameter, behind the Bar: They are drawn in the same manner as the other. Their Bar B is distant from the Plank Three Inches, being shoulder’d at each End, with a very thin flat Tenon, passing thro’ each Limber, and pinn’d on their Outsides, as at _a a_. We do not pin in this Bar thro’ the Limbers, lest the Holes should make these very small Limbers the weaker in that Part. C, the Plank, Two Feet and an Inch long, Five Inches broad, and an Inch and a quarter thick. D, D, the Two double Standards, or Two Pair of Standards, placed into the Plank with Shoulders above, and Tenons pinn’d underneath the Plank, and are Thirteen Inches high above it: These serve for a Pair of Marking-wheels, when Turneps are drill’d on the Level, to keep the Rows all parallel, and at what Distance you please, by setting them according to the Rule already laid down. Sometimes we place the double Standards into the Plank of the Wheat-drill, in the same manner that these are placed. We take off the inner Edge of each Standard at the Top, as at _b b_ and _b b_, for the more easy Admission of the Spindle of the Marking-wheels into the Forks: This Spindle is kept in its Place by Two of the same sort of Wreaths, and placed in the same manner as those describ’d for the fore Hopper of the Wheat-drill. Such Marking-wheels are necessary for drilling upon the Level; but not for drilling upon Ridges. E is the Beam, Two Feet Two Inches and an half long, Four Inches broad, and Two Inches thick: It is thus broad, that the Screws which hold on the cross Piece F, may be farther asunder: The Screws must be placed as near as may be to the Outsides of the Beam, and at equal Distance from each Side of the cross Piece; by which means the Standards are kept the firmer from Turning.