338 Of the Brill-Boxes. Chap. XX, 



them into the Hole nothing but Air, becaufe the Co^ 

 ver never fuffers any thing elfe to come there from 

 above; and the Seed falls out of the Notches by its 

 own Gravity* juft before it reaches the lower End of 

 the tranfverfe Ax, being the Place where the oppofite 

 Ellipfes are farther! afunder ; and none of it is ever 

 carried fo far back as the hinder Semi- ellipfes \ and 

 therefore nothing can be carried into the Hole from 

 below. 



Thus that Part of the Surface of the Spindle will 

 keep the Hole empty and clear, before ever any 

 Notches are cut *, but when the Notches are made on 

 the Spindle, they have yet a much greater Force to 

 drive and expel whatever would enter the Hole, their 

 Shape being fuch as nothing can enter againft their 

 bevel Ends; but what is at their Ends will be thrown 

 prefently into the Mortife; infomuch that when a 

 Spindle has been too little for the Hole by a Quarter 

 of an Inch, that is, a fixth Part of the Diameter of 

 the Hole, it will perform very well in drilling large 

 Species of Seeds ; and when the Mortife is run empty, 

 nothing at all is found in the Hole, it being thus 

 kept void and clean by the Notches. 



Note, That what is here, and elfe where, faid of 

 the Ellipfe of the one Side of the Mortife, muft be 

 underftood the fame of its oppofite Ellipfe, on the 

 oppofite Side of the Mortife. 



All thefe Advantages accruing from this Bevel of 



the Mortife, I believe that, without it, all Attempts 

 of making a Machine to perform the Work, which this 

 does, would have been vain. 



There is alfo within the Mortife unavoidably an- 

 other Bevel, which is as the Reverfe of the former, 

 and notwithstanding is as ufeful ; and this Bevel is, 

 the Inclination which Part ot" the curvilineal Surface of 

 the Spindle, beginning a little above the fore End of 

 the fhorteft Diameter of the Ellipfes, and defcending 

 down to the Seed-paflage, has to the lower Part of 



the 



s 



