343 Of the Wheat-Drill. Chap. XXI. 



both in the Plate and in the Sheat. Thefe thus rivet- 

 ed on do form the Trunk at the Back of the Sheat. 

 The whole Breadth of this Plate is an Inch and 

 Three quarters ; but Three-eighths of an Inch being 

 riveted on to the Sheat, there remains but an Inch 

 and Three-eighths for the Trunk. The Length of 

 the Plate is the fame with the Depth of the Sheat 

 and Share, except that it fhould not reach to the Bot- 

 tom of the Share, by about the Thicknefs of a Barley- 

 corn, to the end that it may not bear againft the 

 Ground, as the Share doth. The Notch at the Bot- 

 tom of the Plate is that which anfwers the Notch in 

 the Tail of the Share : The Corner of the Plate at 

 a we make a little roundifh, that it may not wear 

 againft the Ground. 



This Plate thus riveted on the Sheat, and another of 

 the fame Form on the other Side oppofite to it, com- 

 pofe the Trunk, which is Fig. 6. ad is the Edge a b of 

 the Plate Fig. 5. b c is the like Edge of the oppofite 

 Side of the Trunk. A is the Back of the Sheat, 

 which, together with the Tail of the Share when in its 

 Place, makes the Fore- part or Length of the Trunk. 

 The Thicknefs of this Back of the Sheat is the Width 

 of the Trunk ; and from this Back of the Sheat to 

 the faid Edges of the Plates, may be call'd the Depth 

 of the Trunk. The upper Ends of thefe Two Plates 

 a and b we fpread open a quarter of an Inch wider, 

 for half an Inch down, than the reft of the Trunk, 

 for the more free Reception of the Seed from the 

 Hole of the Funnel : We like wife take care, that the 

 Two lower hinder Concerns of the Trunk do not in- 

 cline to one another, to make the Trunk narrower 

 than the Back of the Sheat, left the Earth mould be 

 held in by them, and fill the Bottom of the Trunk. 



Fig. 7. is one of the hinder Sheats, and appears, 

 in part, at c in Fig. 1 . It is faftened into one of the 

 Beams by its Tenon, which, being driven into a Mor- 

 tife, is pinntl in by a Pin palling thro' the Beam, and 



thq 



