Opticks 1717 - Up

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fLilling Particle, to generate that iJJ0tic-m. And
if it confifted in ‘PrefGon or Motion, propagated
either in 211 inlfant or in time, it should
bend into the Shadon7, For X-drcfl~l‘zb~~ 0rTLhtion.
c:lnllot be propagated in a Fluid in right Lines
beyond an Obftacle which i-Lops part of the MOtiong
but will bend and fpread eriel’y way iota
the quickent P+Jkdinm which lies beyond ,thei
~>blhcle. Gravity tends downwards, but the
Pldhe of Water arifing frsm Gravity tea&
every my with equal force, and is proplzgated
as readily, and with as nxich force fide-zags as
do\vna:al-ds 9 and through &o&d p&g& asi
tlirough firnit ones. The Waves on the SLirfiux!
of itagnaring .Water, paflkg by the iides of 8
broad ObiMe which itops part of them, bend
aftertmrds and dilare thcmfelves gradually inta
the quiet Water behind the Obitacle. The
Uraves, Pulks or Vibrations of the Air, wherefn
Sounds confift, bend manifeflly, though not
fo much 11~s the Wb’aves of .AVat.er. For a Bell
oi- a Chiori may be heard beyond a Hiil which
intel:&pts the fight of the founding Body, and
Sounds are propagated as readily through crook&
cd Pipes as through iireight ones. But Light
is never linotm to follow crooked PaRages nor
to bend info the Shadow. For the fi%‘dStm~
by the Interpofition of any of the Planets teak
to be .feen. And ,fo, do the Parts of the sill
hy the Interpofition of the MOOKI~ Mer~ttry OP
Veum. The Rays which pafs very neief to the
edges.of any Body, are bent a little by the a&i@
uf the Body, xs we fllew’d above ; bat this
.bending is liot towards but fro13 tljfl SliladQvlr3
7, iad