Archimedes Texts

130
as is usual, some little Particles of Air in
the space it deserted, as we ghest by ob
serving, that upon the Application of hot
Bodies to the upper part of the Tube, the
Quick-silver would be a little depress'd.
Lastly, having put both the Tube and the
Vessel it lean'd on into a convenient
Wooden Frame, to keep them from mis
chances: we plac'd that Frame in a Win
dow within my Bed-chamber, that I might
both keep the Mercury from being stirr'd,
and have opportunity to watch from time
to time the Phænomena it was to exhibit.
For the better discovery of which, when
the Quick-silver both in the Tube and
subjacent Vessel was perfectly at rest, we
took notice, by a mark made on the out
side of the Glass, how high the included
Liquor then reach'd.

During several Weeks that the Tube
was kept in that Window (which was very
rarely open'd) I had the opportunity to
observe, that the Quick-silver did some
times faintly imitate the Liquor of a
Weather-glass, subsiding a little in warm,
and rising a little in cold Weather, which
we ascribed to the greater or lesser pressure
of that little Air that remain'd at the top
of the Tube, expanded or condens'd by