- . ( 2 34> 
equiponderant ; but if the new Medium be heavier, the greater 
Body, as being lighter in Specif will loofe more of its weight, 
than the leffer and more compadt; but if the new Mediujrikz 
lighter than the firft, then the bigger Body will outweigh the 
leifer : And this difparity, arifing from the change of Medium's, 
will be fo much the greater, by how much the greater inequality 
of bulk there is between the Bodies formerly equiponderant. 
3. That, laying thefe two together, I confider'd* that 5 t would 
be all one* as to theeffedt to be produced, whether the Bo- 
dies were weighed in Medium's of differing gravity, or in the 
fame Medium^ in cafe its (Jpecific\P) gravity were confidsrably 
alter’d: And confequently, that fmee it appear'd by the Ba~ 
rofeope , that the weight of the Air was fometimes heavier, and 
fometimes lighter, the alterations of ir, in point of gravity, 
from the weight, it was off at firft counterpoiiing of the Buble 
of it, would unequally affedt fo large and hollow a Body, as the 
Buble, and fo final! and denfe a one, as a Metallin weight : And 
when the Air by an increafe of gravity ffrould become a heavier 
Medium * than before, it would buoy up the Glafs more than 
the Counterpoife; and if it grew lighter, than it was atfirft, 
would fuffer the former to preponderate: ( The Illuftrations 
and Proof can fcarce be added in few words ; but, if it be de- 
ffred, I may, God permitting, fend yon them at my next lea- 
fure : ) And though our Englifh Air be about a thoufand times 
lighter, than water, the difference in weight of fo little Air, as 
B but equal in btffk to a Buble, feem’d to give fmall hopes, that 
it would be fenfble upon a Ballance ; yet, by making the Buble 
very large and light* I fuppofed and found the Event, I have 
already related. 
Secondly, The hermetically feal’d: Glafs-buble, I employed*,, 
was of tne bignefs of a fomewhat large Orange, and weigh’d 
about 1 . drachme and 10. grains. But I thought it very poffible, 
if I had been better furniffft with conveniencies (wherein I af- 
terwards found, I was not miftaken ) to make (amongmany, 
that might be expedited to mifearry) fome, that might be pre- 
ferable to this, either for capacity or lightnes, or both; efpe- 
cially if care be taken* that they be not feal’d up, whilft they 
are too hot. For, though one would think, that it were advan- 
tagious 
