Of Winds and Sounds.

^ The aerial Puses are propagated toge -,Jer in great Numbers from different Bodies

'without

ft;

at Time the Pulse passes over 93384 Feet; conse-r ntl y> 951 : 93384 :: I '• 979 Feet == Space pass’d° u gh by a Pulse in one Second of Time.

tyF This then would be the Velocity of the Pulses,{\ij 5re the Particles of Air so very small as that theirLSnitude flxould bear no sensible Proportion to thee tvals between them ; and also if the Medium hadAdmixture of any other Particles but those of pure; Neither of which is the Cafe; for the Particles

Ho

Of

are so gross that they will not pass through the-^ es of Glass any more than Water; and Sir Isaac\f° n supposes them to be of the fame Magnituded the Particles of Water or Salt. If this be so, letDiameter of the Particles, S — Space or IntervalC e We en them ; then will S -f D = Distance of theJlf reg 0 f the Particles. Let N = Number of Particles

ft

ftde

Side of a Cube of Air, then will N S -{- N D =

°f the Cube.

if, Again, let M — Number of Particles of Waterfte o 8>de of an equal Cube, and M D — Side of^ Uuhe of Water ; whence NSstND^MD,if the Density of Air be to that of Water as 1 to

’ We ftall have 1 : A :: N 3 : M 3 ;

N > ltyr i

. . ’ ^ j consequently, M — N A 3 .

Is ^Hnd = md = ND A 3 ,

whence 1 : A 3 ::Wherefore since

A J , and 8 — D X A 3 — 1

, it will be S + Dtherefore D : S

M_.

1 ; whence D ; S X D :: 1 : A S

860, (as we have shewn) then

. S> If therefore A

A ^ ^

Vk" 9 nearly; if we put A — 1000, then A 3 — 10.ib; ® nce D ; S + D :: 1 : 9, or as 1 : iq ; whence theft e > Eter of a Particle of Air will in such Cafe be tofit} C£ nt ® rv al between the Particles as x to 8 or 9. Andthe Motion is instantaneous through the solid Par-ticles

2 35