Chap. XX. Of the Drill-Boxes, 319 



(for another Spring, or new Seafoning of that) ac 

 jnoft would rectify, if the Maker underftood how 

 to mend his own Work. If time did permit, more 

 fhould be faid on this Point, becaufe 1 find it is the 

 Tons Afini of a Workman. Sometimes it may be 

 prevented, when the Spring is too hollow, and gives 

 too much Play. Screw the Screw, that holds it on 

 the Tongue, down clofer, fo that the lower Part of 

 the Screw's Head prefs againfl the Spring, and there- 

 by force its Middle nearer to the Tongue, until you 

 find its Play leiTened to its juft Diftance. 



The Spring, remaining in this compreiTed State, 

 has loft the weakeft, and retains only the ftrongeft. 

 Part of its elaftic Force. Therefore, if you find it 

 then too ftiff, make it weaker by Filing or Grinding, 

 or elk put another into its Place, which is honeftly 

 worth no more than Two-pence. 



This Holding-fcrew has a pretty broad Head, and 

 is fcrewed in by a Notch, like the Screw-pin of a 

 Gun-lock. 



The Hole in the Spring muff, be fomewhat bigger 

 than the Holding- fere w, becaufe the Spring muft 

 have room to move and play thereon. 



If the Middle of the Spring were againfl: the Mid- 

 dle of that Part of the Tongue, that is betwixt its 

 Axis and the Place of PrefTure, the Diftance of the 

 Spring's Hollownefs would be juft half the Diftance 

 of the Spring's Play, to wit, the One-eighth Part of 

 an Inch •, but as the Spring does not quite reach up 

 to the Axis, and reaches much below the Place of 

 PrefTure, the Hollownefs at the Place where the Set- 

 ting-fcrew bears againfl the Middle of the Spring at 

 D, is considerably nearer to the Place of PrefTure 

 than to the Axis cf the Tongue -, this Hollownefs of 

 the Spring at the Setting-fcrew may be fomething 

 more than the One-eighth Part of an Inch, to give 

 the Spring a Quarter of an Inch. Play : but it feldom 

 has fo much. 



