open'd a wide door to it, to let in stormy winds; yet I have found
it to continue very high, in a long stormy wind of 3. or 4. daies.

9. Again, generally it is higher in an _East_ and _North_-wind. (_Caeteris
paribus_) than in a _South_ and _West_-wind.

10. I tryed several times, by strong fumes and thick smoaks to alter the
Air in my Closet; but I cannot affirm, that the _Mercury_ yielded any more,
then might be expected from some increase of heat. Such as have exact
_Wheel-Barometers_, may try whether Odors or Fumes do alleviate the Air.

11. In this Closet I have not in all this time found the extreamest changes
of the Quicksilver to amount to more, than to 23/4, or to 2-7/8. inches, at
most.

12. Very often I have found great changes in the Air, without any
perceptible change in the _Barometer_; as in the dewy nights, when the
moisture descends in a great quantity, and the thickness sometimes seems to
hide the Stars from us: In the days foregoing, and following, the Vapors
have been {158} drawn up so _Invisibly_, that the Air and Sky seem'd very
clear all day long. This I account a great change between ascending and
descending Dews and Vapors (which import Levity and Weight,) and between
thick Air and clear Air: which changes do sometimes continue in the
Alternative course of day and night, for a week or fortnight together; and
yet the _Baroscope_ holding the same.

13. Sometimes (I say not often) the _Baroscope_ yields not to other very
great changes of the Air. As lately (_December_ 18.) an extraordinary
bright and clear day; and the next following quite darkened, some Rain and
Snow falling; but the _Mercury_ the same: so in high winds and calms the
same.

14. I do conceive, that such as converse much _Sub dio_, and walk much
abroad, may find many particulars much more exactly, then I, who have no
leisure for it, can undertake. To instance in one of many, _December_ 16.
last, was a clear cold day, very sharp and strong _East_ wind, the
_Mercury_ very near 30. inches high, about three in the afternoon, I saw a
large black cloud, drawing near us from the _East_ and _South-East_, with
the _East-wind_. The _Mercury_ changed not that day nor the day following;
the Stars and most of the sky were very bright and clear till Nine of the
Clock; and then suddenly all the sky was darkned, yet no change of weather
happened; _December_ 17. the frost held, and 'twas a clear day, till about
two of the clock in the afternoo