[ lOIl] 
be,) comprefs it. As is to be feen ia Ther-mofcopes of alt" 
forts. 
Wh'etber, by ftrengthening the^/r's fpring (in that 
difcouriej he means that oi the former or the latter way, 
I do not well remember. Nor, whether he apply it to 
the increafing, or diminifhing, of its intenfive weight. 
But it may be reafonably accommodated either 
way. 
If the fpring be ftrengthened by comprelEon ; it is 
manifeft that the intenfive gravity mitft be thereby in- 
creafed : becaufe the fame quantity oiJir, and confe- 
qucntly of weight, extenfively taken, is now concra£i:ed 
into a lelTer room, which therefore mufl: be intenfively 
heavyer, (as being the fame weight in a lefFsr bulk:)No'^ 
this may poffibly, as a greater preflure or ftronger fpring, 
force up the Vapours under it with a greater impetus fac- 
cording to the notion I mentioned before J and fo make 
them fiji higher : (unlefs we fhould fuppofe, it may be re- 
iieved,by fliortening the height of t]i^Jtmofphere.)h\xx. not 
loas to make them lighter,- but rather the contrary, as 
preffing them clofer ; much lefs to make them (as the 
phrafe is,) fpecifically lighter then is the Jir it felf 
(though thus compreffed,) and it leaves lefs room to rc^ 
ceivethem between the particles of the compreiTed 
Air , as being now thruft clofer together. 
If the fpring be ftrengthened the other way ; io as by 
heat itufeth to be; this doth rather diminiih its inten- 
five gravity, by thrufting its parts further afunder, and 
fo pofTelling a larger room. Now in cafe this be, by 
a dole Veflel, confined fo as not to expand upward j ic 
will certainly prefs the harder on theftagnant ^ifi^Sil- - 
x^^r under, and make that in the Tube rife higher. But 
in cafe it be unconfined, as in the open Jlir, it may as 
well relieve it felf upward, by making the Atmojphers^ ia 
this part fo much higher. 
Nor is there any neceflity, as to the fubjacent part% 
D d I that c 
