| Boyle, Robert New experiments physico-mechanicall, touching the spring of the air and its effects 1660 |
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245
der 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-
search