Archimedes Texts

131
the heat or cold that affected the ambient
Air. But that which I was chiefly careful
to observe, was this, That oftentimes the
Quick-silver did rise and fall in the Tube,
and that very notably, without conforming
it self to what is usual in Weather-glasses,
whose Air is at the top, nay quite contrary
thereunto: for sometimes I observ'd it in
very cold weather (such as this Winter has
already afforded us good store of) to fall
down much lower then at other times,
when by reason of the absence of both
Frost, Snow, and sharp Winds, the Air was
comparatively much warmer. And I fur
ther observ'd, That sometimes the Quick
silver would for some days together rest
almost at the same height; and at other
times again it would in the compass of the
same day considerably vary its altitude,
though there appear'd no change either in
the Air abroad, or in the temper of the Air
within the Room (wherein was constantly
kept a good Fire) nor in any thing else, to
which either I, or some eminently Learned
Men whom I then acquainted with the
Experiment, could reasonably impute
such a change: Especially considering that
the space wherein the Mercury wandred up
and down, within about five Weeks, a
mounted to full two Inches, of which we