334 &/ $* Drill- Boxes. Chap. XX. 



Spindle, mud be (hotter, or dfe defcend deeper into 

 the Wood, ft> that its End, which turns the Fork, 

 may be in the Middle betwixt its Bottom and the 

 End of its Legs. 



The Uie of the other End of the Spindle is this : 

 When we have a mind that it mould be turned by the 

 left Wheel inftead of the right, we fcrew in the Fork 

 into the Hole I, and place a (hort Screw in the room 

 Of the Fork, to hold down the Slider. 



Note, It is not abfolutely necefTary, that the hol- 

 low Cylinder, which appears on the Sides of the 

 Seed-box, mould both, or either of them, project 

 farther than the Flanches ; but I think it better that 

 k fliould do fo, at lead, on that Side which is next 

 to the Fork. 



This Cylinder mould be bored as true, and as even, 

 as the Barrel of a Fufil is bored : and the Edges and 

 Surfaces of its Ends mufl: be fmooth, and without 

 Jaggs, to the end that the Wreaths may turn glibly 

 sgainft them. 



The Figure or Shape of all Sorts of Seeds difpofes 

 them, more or lefs, to form an Arch, when they are 

 preffed from above, and confined on all Sides. 



The mod effectual Way to prevent this is, to take 

 care, whenever many Seeds are to defcend together 

 by their own Gravity thro' a narrow Paffage, that 

 fuch Paffage be never narrower downwards than up- 

 wards j but, on the contrary, that it be wider down- 

 wards, on fome or one of its Sides ; in which Cafe^ 

 if the Surfaces of all the Sides of this Paffage be 

 fmooth, it is impofiible, that Seeds mould of them- 

 felves form an Arch therein. 



On this Maxim depends the infallible Performance 

 of a Drill, and from hence are derived the Ufes o! 

 the Bevel of the Mortife : What I mean by the Word 

 Bevel, in general, has been already defined. 



The Bevel of the Mortife of the Seed-box is that 

 Inclination of its Sides, whereby it is wider down- 



wards, 



