1der that attracted this weight to obviate
a Vacuum, will ſcarce be ſatisfactory; un
leſs it can be cleerly made out by what li
tle hooks, or other grappling Inſtruments,
the internal Air could take hold of the
Sucker; how ſo litle of it obtain'd the
force to lift up ſo great a weight; and why
alſo, upon the letting in of a litle more
Air into one of our evacuated Veſ
ſels, the attraction is, inſtead of being
ſtrengthen'd, much weaken'd, though,
if there were danger of a Vacuum be
fore, it would remain, notwithſtanding
this ingreſs of a little Air. For that ſtill
there remain'd in the capacity of the ex
hauſted Cylinder ſtore of little rooms,
or ſpaces empty or devoid of Air, may
appear by the great violence wherewith
the air ruſhes in, if any way be open'd to it.
And that 'tis not ſo much the decrement
of the Vacuum within the cavity of the
veſſel that debilitates the attraction, as the
ſpring of the included air (whoſe preſence
makes the decrement) that does it by
reſiſting the preſſure of the external Air,
ſeems probable, partly from the Diſabi
lity of vacuities, whether greater or leſſer,
to reſiſt the preſſure of the Air; and part
ly by ſome of the Phænomena of our Ex-
a Vacuum, will ſcarce be ſatisfactory; un
leſs it can be cleerly made out by what li
tle hooks, or other grappling Inſtruments,
the internal Air could take hold of the
Sucker; how ſo litle of it obtain'd the
force to lift up ſo great a weight; and why
alſo, upon the letting in of a litle more
Air into one of our evacuated Veſ
ſels, the attraction is, inſtead of being
ſtrengthen'd, much weaken'd, though,
if there were danger of a Vacuum be
fore, it would remain, notwithſtanding
this ingreſs of a little Air. For that ſtill
there remain'd in the capacity of the ex
hauſted Cylinder ſtore of little rooms,
or ſpaces empty or devoid of Air, may
appear by the great violence wherewith
the air ruſhes in, if any way be open'd to it.
And that 'tis not ſo much the decrement
of the Vacuum within the cavity of the
veſſel that debilitates the attraction, as the
ſpring of the included air (whoſe preſence
makes the decrement) that does it by
reſiſting the preſſure of the external Air,
ſeems probable, partly from the Diſabi
lity of vacuities, whether greater or leſſer,
to reſiſt the preſſure of the Air; and part
ly by ſome of the Phænomena of our Ex-