Chap. XX. Of the Drill- Boxes. 333 



the Wood at e 9 which prevents its Turning in the 

 Spindle. 



This Crank, by its other End, patting thro' the 

 Two Legs of the Fork E, and equally diftant from 

 the Top and Bottom of it, turns the Spindle by the 

 Motion of the Wheel which is fixed on the other 

 End of the wooden Spindle. If this Crank were to 

 turn the Spindle by a fmgkPin, inftead of this Fork, 

 the Sttd could never be delivered out equally to the 

 Ground •, for as foon as the Pin began to defcend, 

 and decline from being perpendicular to the Horizon, 

 it would, by its own Weight falling down, turn the 

 Spindle half round in a Moment, and there remain 

 with its other End downwards perpendicular to the 

 Horizon under the Spindle, until the Crank reached 

 it there, and fo no Seed would be turned out by one 

 Semicircle of the Wheel, and a double Proportion 

 would be turned out to the Land that was meafured 

 by the other Semicircle •, but the hinder Leg of the 

 Fork, bearing againft the hinder Part of the Crank, 

 prevents this Inconvenience. 



The Line / g is Part of the Surface of a Board, 

 thro' which the wooden Spindle paiTes, and by which 

 it is held in its Place j as (hall be fhewn hereafter. 



The Axis of this wooden Spindle ought to fall 

 into a Line with the Axis of this Brafs Spindle; but, 

 unlefs Care be taken to prevent it, the wooden Spindle 

 will fo much wear the Hole thro' which it paiTes, and 

 be worn by it, as to have Room in the Hole to de- 

 viate from this Exa&nefs, and may defcend fo low, 

 that the Crank may come out of the Ends of the 

 Fork ; and for this Reafon it is, that the Fork is 

 made fo long as it is-, but when this wooden Spindle 

 does, by the Contrivances hereafter fhewn, keep its 

 Axis in a Line with the Axis of the Brafs Spindle, 

 or very nearly fo, then the Legs of the Fork need be 

 no longer than half an Inch 5 and in that Cafe, the 

 Joint of the Crank, which is perpendicular to the 



Spindle, 



