362 Of the Wheat-Drill. Chap. XXI. 



to the laft-mentioned pricked Line : Thefe Four 

 pricked Lines are the lower Edges of this Hole, 

 contiguous to the Seed-box. The Two Lines e f 

 and g h are the upper Edges of the Sides of the 

 Hole, which, being farther afunder than the lower 

 Edges, make the reverfe Bevel of this Hole ; which 

 may be determined by this, that the Surface between 

 thefe Two upper and lower Edges, being Planes, are 

 inclined to one another downwards, in an Angle of 

 about One hundred and Thirty Degrees. The Two 

 Lines e bzndfg, at right Angles with the Two laft- 

 mentioned Lines, make the upper Edges of the Ends 

 of this Hole j and, being nearer together, than the 

 pricked Lines under them, the plane Surfaces, be- 

 twixt thefe Two Lines and thofe Two pricked Lines, 

 friew the Bevel of the Ends of thefe, which are in- 

 clined to each other upwards in an Angle of about 

 Sixty-five Degrees. 



This double Bevel effectually prevents the Seed 

 from arching in the Hole, before it gets into the 

 Mortife of the Seed-box ; and alfo, the Two upper 

 Edges of the Ends of the Hole being nearer together 

 than the lower, there is the more Wood left between 

 thefe Edges and the Screws, which hold the Box to 

 the Bottom, whereby the Board is lefs apt to fplit. 



Then the Box being fcrewed on to the Bottom, and 

 thruft again into its Place, the Spindle, palTing thro* 

 both the Hopper and the Box, keeps the Bottom in 

 its Place : Then D, in Fig. 1 3. is the imaginary Plane 

 of the Top or Mouth of the Hopper, being a rect- 

 angled Parallelogram, and parallel to the Bottom, 

 to which the fore End is perpendicular, and a rectan- 

 gled Parallelogram of the fame Breadth. 



Fig. 15. fhews the fore Side of the whole hinder 

 Hopper, with its Two Cavities, and all its Accoutre- 

 ments, except the Wheels ; the Two Ends A and B 

 being exactly alike, having each of them its Seed-box 

 at the Bottom, in the fame manner as in the one has 

 been dcfcribed. The Bar D holds together the upper 



Parts 



