3 c o . The Four-coulter -d Plough, Chap . XIX. 



The chief, and mod indefpenfably neceiTary thing 

 to be obierved, is, to /place the Four Coulters in fuch 

 a manner, that the Four imaginary Planes defcribed 

 by the Edges of the Four Coulters, as the Plough 

 /noves forwards, be all of them parallel to each other, 

 or very nearly fo - 9 for if any one of them mould be 

 much inclined to, or recede from, either of the other 

 three, they could not enter the Ground together. In 

 order to place them thus, the Coulter-holes mull be 

 made through the Beam, in the manner as they are 

 ihewn in Fig. 3. viz. the Second Coulter-hole is Two 

 Inches and an half more on the Right than the Firf]:, 

 the Third, Two and an half more on the right Hand 

 than the Second, and the Fourth, Two Inches and 

 an half more on the right Hand than the Third, con- 

 formable to the Four Incifions or Cuts they are to 

 make in a Ten-inch Furrow : And becaufe no fingie 

 Beam is broad enough to hold the Four Coulter-holes 

 at this Diftance, we are forced to add the Piece fhewn 

 in Fig, 16. The Second Hole is made Part in the 

 Beam, and Part in this Piece; the Third and Fourth 

 are made wholly in this Piece, in which a, if, c, are 

 the Ends of the Three Screws, which faften the Piece 

 to the right Side of the Beam by their Nuts. 



The Diftance of Two Inches and an half, by 

 which each of the Three added Coulters (land more 

 to the right Hand than* that immediately behind it, 

 mud be reckoned from the Middle of one Hole to 

 the Middle of the other. 



The Fore-part of every Hole muft incline a little 

 towards the Left ; fo that the Backs of the Coulters 

 may not bear againft the left Side of the Incifions 

 made by the Edges. 



Each Hole, being a Mortife, is one Inch and a 

 quarter wide, with its Two oppofite Sides parallel 

 from Top to Bottom ; each of theft Mortifes, or 

 Holes, *are long at Top Three Inches and an half, and 

 at Bottom Three Inches; the Back-part, or Hinder- 

 end a 



