1Bottom of Water, is the exceſſe of their Gravity, above the
Gravity of the Water; and on the contrary, the exceſs of the
Waters Gravity above the Gravity of thoſe, is the Cauſe that others
do not deſcend, rather that they riſe from the Bottom, and aſcend
to the Surface. This was ſubtilly demonſtrated by Archimedes in
his Book Of the NATATION of BODIES: Conferred afterwards
by a very grave Author, but, if I erre not inviſibly, as below for
defence of him, I ſhall endeavour to prove.
Gravity of the Water; and on the contrary, the exceſs of the
Waters Gravity above the Gravity of thoſe, is the Cauſe that others
do not deſcend, rather that they riſe from the Bottom, and aſcend
to the Surface. This was ſubtilly demonſtrated by Archimedes in
his Book Of the NATATION of BODIES: Conferred afterwards
by a very grave Author, but, if I erre not inviſibly, as below for
defence of him, I ſhall endeavour to prove.
merſion of
ids in the
ter.
ids in the
ter.
I, with a different Method, and by other meanes, will endeavour
to demonſtrate the ſame, reducing the Cauſes of ſuch Effects to
more intrinſecall and immediate Principles, in which alſo are
vered the Cauſes of ſome admirable and almoſt incredible
dents, as that would be, that a very little quantity of Water, ſhould
be able, with its ſmall weight, to raiſe and ſuſtain a Solid Body, an
hundred or a thouſand times heavier than it.
to demonſtrate the ſame, reducing the Cauſes of ſuch Effects to
more intrinſecall and immediate Principles, in which alſo are
vered the Cauſes of ſome admirable and almoſt incredible
dents, as that would be, that a very little quantity of Water, ſhould
be able, with its ſmall weight, to raiſe and ſuſtain a Solid Body, an
hundred or a thouſand times heavier than it.
And becauſe demonſtrative Order ſo requires, I ſhall define
tain Termes, and afterwards explain ſome Propoſitions, of which,
as of things true and obvious, I may make uſe of to my preſent
poſe.
tain Termes, and afterwards explain ſome Propoſitions, of which,
as of things true and obvious, I may make uſe of to my preſent
poſe.
DEFINITION I.
I then call equally Grave in ſpecie, thoſe Matters
of which equall Maſſes weigh equally.
of which equall Maſſes weigh equally.
As if for example, two Balls, one of Wax, and the other of ſome
Wood of equall Maſſe, were alſo equall in Weight, we ſay, that
ſuch Wood, and the Wax are in ſpecie equally grave.
Wood of equall Maſſe, were alſo equall in Weight, we ſay, that
ſuch Wood, and the Wax are in ſpecie equally grave.
DEFINITION II.
But equally grave in Abſolute Gravity, we call two
Sollids, weighing equally, though of Maſs they be
unequall.
Sollids, weighing equally, though of Maſs they be
unequall.
As for example, a Maſs of Lead, and another of Wood, that
weigh each ten pounds, I call equall in Abſolute Gravity, though
the Maſs of the Wood be much greater then that of the Lead.
weigh each ten pounds, I call equall in Abſolute Gravity, though
the Maſs of the Wood be much greater then that of the Lead.
And, conſequently, leſs Grave in ſpecie.
DEFINITION III.
I call a Matter more Grave in ſpecie than another, of
which a Maſs, equall to a Maſs of the other, ſhall
weigh more.
which a Maſs, equall to a Maſs of the other, ſhall
weigh more.