needs be prefl to a more than ordinary hight, and as a con- 
curring caufe, the fhrinking of the lower parts of the Air 
into lelTer room by cold, muft needs caule a defcent of the 
upper parts of the Atmoffhere to reduce the cavity made by 
this contraftion to an Mqmlihrium. 
6. Why after very great Storms of Windy when she Mercury 
has been very loWy it generally rifes again very fajl. This I 
liave frequently obferved, and once found it rilen an Inch 
and half in lefs than fix hours, after a long continued Storm 
of South- Weft Wind. This feems to be occafioned by the 
fudden accefEon of new Air to fupply the great Evacuation 
which fiich continued Storms make thereof, in thole places 
where they happen ( zs in the third remark^ and by the 
Recoile oftheJ'/V, after the force ceafes that impell'd it; 
andthereafbn why t\\Q Mercury rifes fb fall:, isbecaufethe 
Air being very much rarified beyond its mean denfity, the 
neighbouring Air runs in the more fwiftly to bring it to an 
Equilibrium^ as we fee water runs the fafter for having a 
great declivity. 
7. Why in more Northerly Places the Variations of the Baro- 
fcope are greater than in the more Southerly ; The truth of the 
matter of faQ: is proved from obfervations made at Clermont 
and ?a,ris compared with others, made at Stokholmy as may 
be feen in the Appendix to Mr. Pafcals book before cited. 
The reafbn I conjeOiure to be,that the more Northerly parts 
have uiiially greater Storms of Wind than the more Souther- 
ly, whereby the Mercury fliould fink lower, in that extream ; 
and then the Northerly Winds bringing the Condenfed and 
Ponderous Air from the Neighbourhood of the PoU^ and 
that again being checked by a Southerly Wind, at no great 
diftance^ and fo heaped, muft of neceffity make the ik&r- 
cury in fiich.cafe ftand higher, in the other extrearp» 
8. And Laftly, Why near the Equinoftial as at Barbadoes 
md St. Helena, there is. very little or no Variation of the height 
of the Barometer. This Remark above all others. Confirms 
the Hyfothefis of the Variable Winds being the caule of 
theft 
