1ambient Air are in an Æquilibrium as to
preſſure, and the weight of the Water
that keeps them ſeparate is ſcarce conſi
derable. Whereas in ſuch a Tube as we
are ſpeaking of, the Air within is very
much more dilated then that without; and
'tis not ſo much the ſpring or reſiſtance
of the included Air, as the weight of the
Mercurial Cylinder it ſelf that hinders the
Quick-ſilver from aſcending higher; for
if we ſhould ſuppoſe that deſerted part of
the Tube perfectly devoid of Air, yet
would the Quick-ſilver riſe but a little
higher in it, and be far from filling it, in
regard the outward Air would not be
able to impel up ſuch a weight much
higher: whereas it may, by our former
Experiments appear, that if all the Air in
the upper part of a Weather-Glaſs were
away, the Water would be impell'd up to
the very top of it, though the Pipe were
above thirty Foot long.
preſſure, and the weight of the Water
that keeps them ſeparate is ſcarce conſi
derable. Whereas in ſuch a Tube as we
are ſpeaking of, the Air within is very
much more dilated then that without; and
'tis not ſo much the ſpring or reſiſtance
of the included Air, as the weight of the
Mercurial Cylinder it ſelf that hinders the
Quick-ſilver from aſcending higher; for
if we ſhould ſuppoſe that deſerted part of
the Tube perfectly devoid of Air, yet
would the Quick-ſilver riſe but a little
higher in it, and be far from filling it, in
regard the outward Air would not be
able to impel up ſuch a weight much
higher: whereas it may, by our former
Experiments appear, that if all the Air in
the upper part of a Weather-Glaſs were
away, the Water would be impell'd up to
the very top of it, though the Pipe were
above thirty Foot long.
We may next conſider, that this ra
rified Air at the upper part of our Tube
being exactly ſhut up betwixt the Glaſs
and the Quick-ſilver, it was ſcarce ſubject
to any diſcernable alterations, ſave thoſe
it receiv'd from heat and cold.
rified Air at the upper part of our Tube
being exactly ſhut up betwixt the Glaſs
and the Quick-ſilver, it was ſcarce ſubject
to any diſcernable alterations, ſave thoſe
it receiv'd from heat and cold.
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