384 Of the Turnep-DrilL Chap. XXIL 



The Harrow is pinned on to the Beam by the Iron 

 Pin, Fig. 9. paffing thro' the Hole of the Leg at g $ 

 and thro' the Beam, and alfo thro' the other Leg on 

 the other Side of the Beam, where the Screw at the 

 End of the Pin has a Nut fcrew'd on it. This Pin 

 is round from its Head ail the Way thro' the firft 

 Harrow-leg^ and thro' the Beam \ but all that Part 

 of the Pin, which is in that Leg againft which the 

 Nut is fcrew'd, mud be fquare •, whereby that Part 

 being bigger than the round Part of the Pin, and 

 than the Hole in the lafb-mention'd Leg, cannot turn 

 in the Hole of that Leg ; for if it did, the Nut would 

 be foon unfcrew'd by the Motion of the Harrow ; but 

 the Pin muft have room to turn in the other Leg, and 

 in the Beam. This fquare Part of the Pin is {^n 

 at a, Fig. 9. The whole Length of the Pin, from 

 its Plead to the End or the fquare Part at a, where the 

 Screw begins, is of the Thicknefs of the Two Legs, 

 and of the Breadth of the Beam. 



We fometimes let the Legs of the Harrow Two 

 Inches wider afunder, by making them each an Inch 

 thicker at their fore Ends in their Infide, and ready- 

 ing Five or Six Inches behind their Iron Pin : Thefe 

 thicker Parts, bearing againft the Beam, keep the 

 hinder Part of each Harrow-leg an Inch diftantfrom 

 the Sides of the Beam, whereby the Harrow-legs are 

 Six Inches afunder, inftead of Four, by means of 

 thefe added ThickneiTes. 



When a Drill is taken up to be turn'd, the Perfon 

 that does -it, takes hold of the Harrow-head, and lifts 

 it up: The Legs of the Harrow, bearing againft the 

 crois Piece, fupport the whole Weight of the Drill. 



W T hen the Harrow does not go deep enough, wc 

 tie a Stone upon the Middle of the Harrow-head, by 

 a String that palles thro' the rloles at h. All the Wood 

 of this Plough and Harrow is Afli, except the 

 Limbers. 



The 



