Chap. XXI. Of the ft> heat-Drill. 3 6 r 



Top, that they may not turn in the Wood ; and 

 their Heads muft either be let into the Wood, even 

 with the Surface, or ejfe the Sides B C of the Hop^ 

 per muft be cut for thefe Heads of the Screws to pafs 

 in under them. 



This bottom Board, which holds the brafs Seed*- 

 box, is Four Inches broad, and full half an Inch 

 ;hick, and at each End a quarter of an Inch longer 

 than the Seed-box : This Piece is firft thruft in Aid- 

 ing upon the Two added Pieces of Board, until its 

 fore End comes under the fore Side of the Hopper, 

 and its hinder End under the hinder Side •, then fet- 

 ting the Hopper with its Bottom upwards, the Spindle 

 being thro' the Seed-box, and Holes of the Hopper, 

 we hold the Seed-box hard upon the Bottom, at equal 

 Piftance from each End of it, whilft the Holes are 

 bored thro' the Bottom, by the Holes at each End of 

 the Seed-box ; and then the Screws, being put thro', 

 fcrew on the Box-, and when that is done, we make 

 a Mark upon the bottom Board, with the Compafifes, 

 pn each Side of the Brafs Box, beginning from the 

 Ends of the Axis of the Tongue, reaching as far 

 backwards as is the Length of the Mortife : Thefe 

 Two Lines or Marks are a Direction for cutting the 

 Hole in the Bottom of the Hopper, thro' which the 

 Seed defcends into the Seed-box •, then we pull out 

 the Spindle, then draw out the Bottom, take off the 

 Seed-box, and cut the Hole in the Bottom in the 

 manner I will now defcribe in Fig. 14. where the Two 

 pricked Lines a b and c d are the lower Edges of the 

 Hole, and the fame with the Two Lines mentioned 

 to be marked by the Sides of the Seed-box. The 

 pricked Line a d 9 being at right Angles with the Two 

 former, is the lower Edge of the fore End of the 

 Jiole, and exactly over the Axis of the Tongue, and 

 parallel to it. The pricked Line b c is the lower Edge 

 of the hinder End of the Hole, which is juft over 

 ;he hinder End of the Mortife, and parallel and equal 



to 



