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but runneth in Silence,if it be of any depth But the very Stream upon Shal- 

 lowest Gmvell,or Pebble 5 will be heard. And Waters, when they beat up- 

 on the Shore, or are ftraitned, ( as in the falls of Bridges • ) Or are .darned 

 againft themfelves,by Winds, give a Roaring Noifc. Any peece of Timber, or, 

 I Hard body, being thruft forwards by another Body Contiguous, without 

 j knocking, giveth no Noife. And fo Bodies in weighing , one upon another, 

 : though the upper Body prefs the lower Body down , make no Noife. So the 

 Motion in the Minute parts of any Solid Body , ( which is the Principal 

 Caufe ot Violent Motion, though unobferved 5 )palfeth without S ound- 7 For 

 I that Sound , that is heard fometimes, is produced only by the Breaking of 

 j the Air 5 And not by the Impulfion of the Parts. So it is manifeft ; That 

 I where the Anteriour Body giveth way, as fait as the Pofteriour cometh 

 j on, it ma£eth no Noife, be the Motion never fo great, or fwift. 



Air open, and at large, maketh no Noife, except it be fharply percuffed • 

 j As in the Sound of a String , where Air is percuffed by a hard and ftiff 

 Body •, And with a fhsrp loofe : For if the String be not drained , it ma- 

 keth no Noiie. But where the Air is pent, and ftraitned, there Breath, or 

 other Biowing,(which carry but a gentle Percuffion,)[uffice to create Sound: 

 As in Pipes, and vpind-wfiruments. But then you muft note, that in Recor- 

 ders, which go with a gentle Breath, the Concave of the Pip, were it not for 

 the Fipple, that ftraitneth the Air ,(much more then the Simple Concave ) 

 would yeeld no Sound. For, as for other Wind-Infiruments, they require a 

 forcible Breathy As T rumpets, Cornets, Hunters Horns, &c. Which appea- 

 reth by the blown-Cheeks of him that windeth them. Organs alfo are 

 blown with a ftrong wind, by the Bellows. And note again, that 

 fome kind of Wwd-Injlruments , are blown at a fmall Hole in the fide, 

 which ftraitneth the Breath at the firft entrance The rather , in refpeel: of 

 their Traverfe,md Stop above the Hole, which performeth the Tipples Part*, 

 As it is feen is Flutes, 2nd Fifes, which will not give Sound , by a blaft at the 

 end,as Recorders, &c. do. Likewife in all whirling, you contract the 

 Mouth-, And to make it more fharp,Men fometimes ufe their Finger. 



But in Open Air, if you throw a Stone, or a Dart, they give no Sound : No 

 more do Bullets, except they happen to be a little hollowed in the Cafting • 

 Which Hollownefs penneth the Air: Nor yet Arrowes , except they be 

 ruffled in their Feathers, which likewife penneth the Air. As for Small 

 Whiflks, or Shpheards Oaten Pipes ; they give a Sound, becaufe of their ex- 

 treme Slendernefs, whereby the Air is more pent, than in a wider Pipe. 

 Again the Voices of Men , and Living Creatures , pafs through the throat, 

 which penneth the Breath. As for the $ewes Harf, it is a (harp Percuffion } 

 And befides, hath the vantage of penning the Air in the Mouth. 



Solid Bodies,^ they be very foftly Percuffed, give no Sound -As when a Man 

 treadeth very foftly upon Boards. So Chefis or Doors in fair weather, when 

 they open eafily, give no Sounds And Cart-Wheeles fqueak not when they are 

 liquourcd. 



The Flame ofT apers,ov Candle ^though it be a fwift Motion, and breaketh 

 the Air, yet paileth without Sound. Air in 0^w,though(no doubt)it doth 

 (as it were/ooyl,and dilate it felf,and is repercufled-,yet it is without Noife. 



Flame percuffed by Air, giveth a Noife As in blowing of the Fire by Bel- 

 lowes ; Greater, than if the Bellowes mould blow upon the Air it felf. 

 And fo likewife Flame Percufjing the Air fronglyias when Flame fuddenly 

 taketh and openeth, )giveth a Noife • So great Flames, whiles the one im- 

 pelleth the other ,give a bellowing Sound. 



There 



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