(-58) 
drawn up fo Invijlbly^ that the Air and Sky feem'd very clear 
ail day long. This I account a great change between afcend- 
ing and defcending Dews and Vapors ( v/hich import Leviry 
and Weight,) and betv/een thick Air and clear Air; which 
changes do fometimes continue in the Alternative courfe of 
day and night, for a week or fortnight together i and yet tlie 
Barojcope holding the fame. 
♦ 
j.l. Sometimes ( I fay not of ten ) the Barofcope^^itMiviot 
to other very great changes of the Air. As lately ( December 
i8. } an extraordinary bright and clear day i and thenext 
following quite darkned, fome-Rain and Snow falling; but the 
Mercury the fame : fo in high winds and calms the fame. 
14. I do conceive, thatfbchas convQvkmwda Sub dio,2.nA 
walk much abroad, may find many particulars much more 
cxadtly, then I, who have no leifure for it, can undertake. 
To inftance in one of many, December. 16. lafl, was a clear 
cold day, very fliarp and flrong £f?y? wind, the A/^rr/!^?;)/ very 
near ^o. inches high, about three in the afternoon, I faw a 
large black cloud, drawing near us from the Eajl and South- 
Eajf^ with the Eaji^wind. The Mercury changed not that day 
not the day following j the Stars and moft of the sky were 
very bright and clear till Nine of the Clock ; and thenfud- 
denly all the sky was darkned, yet no change of weather hnp*- 
penedi D^rfw^^r 1 7. the froft held, and 'twas a clear day, till 
about two of the clock in the afternoon ; and then many thick 
clouds appeared low in the Wefii yet no change of the wea- 
ther here ; the Wind, Froft, and Quick-filver, the fame, 
December 1 8. thQ Mercury fell almoft^of an inch, and the sky 
and Air fo clear and bright and cold with an Eaft-rpwd^ that I 
wondred Vv^hat could caufe the Mercury to clefcend. I Ex^ 
pedted, it fliould have afcended, as ufually it does in fuch 
clear skys. CafuaHy I fent my fervant abroad, andhedil^ 
covered thereniote Hills, about zo, miles off, cover d with 
fnow 
