r, in which
that mouth or open end is immersed, there is wont to remain (as is commonly
known to those acquainted with this Experiment) a Cylinder of Quicksilver
suspended in the Tube, about 28, 29, or 30. inches high; measuring from the
surface of the Stagnant Quicksilver perpendicularly; (but more or less,
within such limits, according as the Weight or Pressure of the Air
incumbent on the External Stagnant Quicksilver exposed to it, is greater or
less:) leaving the upper part of the Tube void. (Both which Instruments
being the contrivance of the Honourable _Robert Boyle_, they are by him
more particularly described in his _Physico-Mechanical Experiments touching
the Air, Exper._ 17. and 18. and in his _Thermometrical Discourses_,
premised to his _History of Cold_.)

Now, according to both these Instruments, having kept a daily _Register_ of
Observations for more than a whole year (saving when I have been for some
short time absent from home) I find my Notes for that day to be these.

_January._ |_Thermoscope._|_Baroscope._ 1665/6.
Day. Hour. | inches. | inches.
19. 8. Morn. | 14-1/16. | 29-1/2. Hard frost. Close.
4. Even. | 14-3/8. | 29-1/4. Hard frost. Cloudy.
9. Even. | 14-3/4. | 29-3/4. Rain. Wind
20. 8. Morn. | 15-1/4. | 28-3/4. Sunshine. Wind.

So that, there being in the morning (_January_ 19.) a hard frost (which
began the day before about 4. of the Clock in the {168} afternoon (_Jan._
18.) and continued (with us) till about 5. of the Clock in the afternoon of
that day, _Jan_ 19. with some fierceness) and the weather, _Jan._ 19. being
in the morning, close; and cloudy all the day, with little of Sun-shine;
the Liquor in the _Thermoscope_ was very little raised, by 4. of the Clock
afternoon, that is, but 5/16 of an inch (which, had the Sun shone, would,
it's likely, have been near an Inch:) and after that time (or somewhat
before) had there been no considerable change of weather, it would upon the
Sun's setting have fallen (and probably so it did, till about 5. of the
Clock, though I took no Observation in the interim.) But, contrary to what
would have been expected, it was at 9. of the Clock at night, higher by 1/8
of an inch, than it had been at 4. occasioned by the change of weather, the
Frost suddenly breaking, with us, between 5. and 6. of the Clock; about
which time also it began to rain, and continued raining tha