OF BODIES.Chap.XXVIir; 



' 



be heard fome miles off, if one lay their eare to the ground j 

 and more fenfibly if one make a little hole in the earth, and pat 

 ones eare into the mouth of it; but moft of all if one fet a Drum 

 Jrnooth upon the ground, and lay ones eare to the upper edge of 

 it ; for the lower membrane of the Drum isihakedby the mo- 

 tion of the earth, and them mult iplyeth that found bythehol- 

 lovv figure of the Drum in the conveying it to the upper mem- 

 brane, upon which your care leaneth. Not much unlike the 

 tympane or drum of the eare ; which being fhaked by outward 

 motion, cau/eth a fecond motion on the infide of it correfpon- 

 dent to this firfi ; and this having a free paflage to the braine, 

 itriketh it immediately and lo informeth it how things move 

 without; which is all the myftery of hearing. 



If any thing doe breake or fk>p this motion , before it make 

 our eare,it is not heard. And accordingly we fee that the found Where the mo. 

 of bells or artillery is heard much further if it have the conduct ' 



of waters, then through the pure ayre : becaufe in fiich bodies 

 the great continuity of them maxeth that one pa* cannot 

 fhake alone, and upon their fuperficies, there is no notable un- 

 evennefTe, nor no denfe thing in the way to checke the motion 

 (as in the ayre,hils, buildings, trees, and ftich like;) fbthat the 

 fame making goetha great way. Andtoconfirmc that this is 

 the truereafon, I have feverall times ob(crvcd,that landing by 

 a river fide, I have heard the found of a ring ofbells,,mucn more 

 di/tinctJy and lowd,then if I went fbme diftance from the water, 

 though neerer to the tteeple from whence the found came. 



And it is not only the motion of the ayre, that maketh found 

 in our eares : but any motion that hath accefTe to them in fiich 

 a manner as to fliaKe the quivering membranous tympane 

 within them, will reprefent unto us thofe motions which are 

 without, and fo make fuch a found there as if it were conveyed other motions 

 onelybytheayre. Which is plainelyfeen, when a man lying a comminj to 

 good way under water, rtiall there heare the fame founds.as are 8 



made above in the ayre ; but in a more clumfie manner ; accor- 

 ding as the water, by being thicker^and more corpulent is more 

 unwieldy in its motions. And this I have tried often ; flaying 

 under water as long as the neceflity of breathing would permit 

 mc.Which meweth that the ayre being fmartly moved, moveth 

 the water gjfo, by mcanes of its ccntinwty with it -, vad that li- 



Aa quid 



