CENTURY I. t5 



glass, pressing it somewhat hard ; and after you 

 have drawn it some few times about, it will make 

 the water frisk and sprinkle up in a fine dew. This 

 instance doth excellently demonstrate the force of 

 compression in a solid body : for whensoever a solid 

 body, as wood, stone, metal, &c. is pressed, there is 

 an inward tumult in the parts thereof seeking to 

 deliver themselves from the compression : and this 

 is the cause of all violent motion. Wherein it is 

 strange in the highest degree, that this motion hath 

 never been observed, nor inquired ; it being of all 

 motions the most common, and the chief root of all 

 mechanical operations. This motion worketh in 

 round at first, by way of proof and search which 

 way to deliver itself: and then worketh in progress, 

 where it findeth the deliverance easiest. In liquors 

 this motion is visible ; for all liquors strucken make 

 round circles, and withal dash ; but in solids, which 

 break not, it is so subtile, as it is invisible ; but 

 nevertheless bewrayeth itself by many effects ; as in 

 this instance whereof we speak. For the pressure 

 of the finger, furthered by the wetting, because it 

 sticketh so much the better unto the lip of the glass, 

 after some continuance, putteth all the small parts 

 of the glass into work, that they strike the water 

 sharply ; from which percussion that sprinkling 

 cometh. 



10. If you strike or pierce a solid body that is 

 brittle, as glass, or sugar, it breaketh not only where 

 the immediate force is ; but breaketh all about into 



