Chap. XIX". The Four- coulter d Plough. 301 



end, of each Coulter-hole is not perpendicular, but 

 oblique, and determines the Obliquity of the Stand- 

 ing of the Coulter, which is wedged tight up to it 

 by the Poll-wedge f, Fig. 1. as all Coulters are. 



Fig. 17* Is a Coulter ; a b is its Length, being 

 Two Feet Eight Inches, before it is worn \ e d is its 

 Edge, Sixteen Inches long •, d c is the Length of its 

 Handle, Sixteen Inches •, this is made thus long, at 

 fir ft, to ftand above the Plough, that it may be driven 

 down lower, according as the Point wears fhorter ; 

 this Handle is One Inch and Seven Eighths broad, 

 and Seven Eighths of an Inch thick, equally thro' 

 its whole Length: Its Breadth and Thicknefs might 

 be defcribed by a rectangled Parallelogram. 



In all Ploughs this firft Coulter is, or ought to be, 

 placed in the Beam in manner following ; viz. its 

 Back to bear againfl the Back of th^ Coulter-hole, its 

 right Side above to bear againfl the upper Edge of the 

 Coulter-hole, and its left Sice to bear againfl the 

 lower Edge of the Coulter-hole j fo that always Three 

 Wedges at leafc will be neceftary to hold the Coulter; 

 the Poll-wedge before it, as at /, in Fig. 1. another 

 "Wedge on the left Side of it aJDOve, and a Third on 

 the right Side underneath: The Coulter-hole muft 

 be fo made, that the Coulter (landing thus acrofs the 

 Hole, its Point may incline fo much towards the Left, 

 as to be about Two Inches and an half farther to the 

 Left (a) than the Point of the Share, if it were driven 

 down as low as it ; but it never ought to be fo low 

 in any Plough : As to its bearing forwards, the Point 

 of the Coulter mould never be before the Middle 

 of the Point of the Share : What Angle the Coulter 

 would make with the Bottom of the Share, may be 

 feen by the Poilure it ftands in, in Fig. 1. If it 

 fhould be let much more obliquely, it would have a 



(a) I find that fomeumes it is neeefTary in fome of thefe 

 Ploughs for the Point of this Coulter to Hand yet farther on the 

 Left of the Share's Point. 



greater 



