Be ois aa ay 4 
. 
Lightis inaninftant. This may be tried in far greater diltances, allbwing | 
| greater Lights and Sounds. » nko su OM en ee 
~~ lis generally knowniatid obferved) that Light ahd the object of Sight, | 210. 
| move {fwifter than Sound; for wefee the flath of'a piece is (eed {Sdner, 
| thanchenoifeisheard. And inhewing Wood, ifone {ome diftance’ off, He’ 
7 fhall fecthe Arm lifted up fora fecond ftroke, before he hearthe noife of the | 
firft ; and thegreatet the diftance,the greater is the preventién: As we feci 
} Thander,whichis far off, where the Lightning precedeth the crack a good {pace. + 
‘ Colours, when they reprefent themfelves tothe Fye,faderiornér melt} 211. 
| not by degrees, butappear ftill in the fame ftrength ; but Sounds melt, and 
vanifh, by little and little’ The caufe is, forthat Colours participate nothing 
with the motion of the Air, but Sounds do. Anditisa plain argunent that 
} Sound participatcth of fome Local Motion of the Air, (as acaufe Sine gud 
| non) in that it perifheth fo fuddenly : For inevery Se@ion, or Impulfion of 
‘| the Air, the Air doth fuddenly reftore and reunite ir felf, which the Water 
| alfodoth, butnothing fofwifly, = ae : 
N the Tryals of the Paflage, or not Paffage of Sounds, you muft take heed. | Experiments 
I you miftakenotthe paffing by the fidesot aBody, for the paffing thorow |"° nal 
aBody; aid therefore you muft make the Intercepting Body very clofe ; | pafzge and 
for Sound will pafs thorow a {mall chinck. Me Ot PTE 
Where Sound paffeth thorow a hard, or clofe Body (as thorow Water, of ae = 
| thorow a Wall, thorow Metal, asin Hawks Bells ftopped, &c.) the hard ie 
or clofe Body, muftbe but thin and fmall; for elfe it deadeth and extinguifh- 
éth the Sound utterly. And therefore, in the Experiment of Speaking in | 
Air under W ater, the voice muft not be very deep within the Water,for then 
the Sound pierceth not. So if you fpeak on the further fide of a clofe Wall, 
ifthe Wall bevery thick,you fhallnot be heard ; andifthere were an Hogs- } 
head: empty;* whereof the fides were fome two footthick, and the Bung- 
hole ftopped. “I conceive, the refounding found bythe Commudication of 
the outward Air withthe Ar within, would belittle or none, but onely you 
‘fhall hear the noife of the outward Knock, asif the Veflel were full. 
itis certain,that in the paflage of Sounds thorow hard Bodies, the Spirit | 313. 
or Pneumatical part of thehard Body it felf dothco-operate ; but much 
‘better, when the fides of that hard Body are ftruck, than when the percufli- 
Jon isonely within, withouttouch of the fides. Take therefore a Hawks-Bell, 
| the holes {topped up, andhang it by athred within a Bottle-Glafs, and {top 
the Mouth of the Glafs very clofe with Wax,and then fhake the Glafs,and fee. 
whether the Bell give any Gund at all, or how weak? But note,that you muft 
inftead of Thredtakea Wire, or elfe let the Glafs haveagreat Belly, left 
} when you fhake the Bell, itdafh upon the fidésof theGlafs. 
}  iktisplain thataverylong anddownright arch for the Sound to pafs, 
will extineuifh the Sound quite, fo that that Sound, which would be heard 
ees Wall, will noe beheard over aChurch; northat Sound, which will | 
boheard, if you ftand fome diftance from the WVall, will be heard if you 
ftand clofe under the VVall. ain | 
_« So'tand Foraminous Bodies inthe firft'creation of the Sound, will dead 
ity for the ftrikingagainft Cloth or Fur,will make little found, as hath been 
| faid: But in the paflage of the found, they will admit itbetcer than harder. 
odies,as we fee, that Curtainsand Hangings will not ftay the found much; 
| bur Glafs windows, if they be very clofe, will check a found more, than the 
|like thickiefsof Cloth. VVe fee alfo intherumbling of the Belly, how } 
ly the'Sound pafleththorow theGuts and Skin. eo: : 
IA meses | 
ie a 
