lA.Iingtm^ of that important propofitbn, toothbg the mo- 
tion made in a Cycloid. 
'Tht fecondoix\itm^ would haveconfiftcd of tte Motioo of 
Vquids 5 where he would not only have dcmonftrated all the 
fbmomenaoi the Celerity of L^quorSj of the Force of thdr 
PrefTurc, of the Direciionand Figure they take 10 their Jets^ 
Courfe, and Equal Poife \ but alfo comprehended the whole 
ScitnctoiTneumaUques, ffince Air is ^ liquid 5 ) the force of 
Springs, Rarefaftion and CondeDfationj and the ftrangeViV 
olence of Gun-powder kindled, and all the ilew Expcrinieiits 
oitht Vacuum J and the reafon of all thofe furprifiog EIFcds 
obfervcd io them. 
The r^/W would have treated of the motion o^ Vibration,, 
Where he would have defcribed a Pe^dukmh^vrng all its vh. 
brations fynchronous, together with a demonftratioOj that all 
Vibrations of a cord extended do laft equally long ^ that the 
Vibrations of two cords of an equal thicknefs and tenfioo are ia 
areciprocal proportion of the Length of the cordsj whereas 
in Pendulums they are only in a fub-duplicate proportion 5 that 
in equal cords the Vibrations are in a fub-duplicare proporti- 
on of the forces or weights that make them teofe 5 that the 
Vibrations are likewife id a fub-duplicaf is proportion of the 
thickncfs of the cords equally long and equally tenfe. And 
fo he would have demonftrated by the Caufes,what ever hath 
becnobferved by Experience in Sounds and in the Harmony 
of tenfe Bodies* 
The fourth would have difcourfed of the Motion of Dndu- 
lation^ taking for an Example thofe Circles that are made on 
the furface of the water upon the throwing in of a (tone. 
Where alfo would have been confidered fome Circles like the 
formeTj fuch as may be formed in the Air^ and even in (ome 
other more (ubtile Bodies, which manifeft experiments evince 
to be fpred every-wliere. And of fuch Circles he would ha ve 
cxaminedjhow they may be formed, how their motion is com- 
niUDicated, what are the lines of their diredlion, with what 
force they may aft near or far off, how they may refled and 
ffefra(3:. Further, fuppofing that Sound hath for its vehicle 
^hiskindof momnm the Air, he- would have explaiged all 
