C€s Into which the Air is cbntrafled, are reciprocal to 
.their refpeftive Preffures, and for that while the Inftru- 
ment is out of the Water the PrefTiire / anfwer'd to the 
Space (? therefore, F.-f- a:f::C: Space which 
the Air takes up in the Inftrumeot under Water ; there- 
fore, -d — ' ^ — that Part of the Tube which is Dof- 
' F ^ 
fefsM by Alr ^ a/? (fuppofing the Tube's Area 2=^ ^ J. 
Therefore f c — ¥ d — a d^'^ a n ~'r a a n. Therefore 
F -1- — X /izry PutF 2^-, there- 
fore it /t -^2 ^ ^ = — —therefore a :fiLZL^-A. 
Then fuppofe the Atmofpbere's Gravity lefs fo much as 
to fink the $ ri- Inch — i.4of Water,and therefore putting 
9 — F — 1.4, and in the laft Equation a inftead of and 
:^ inftead of^jYou have cc = V-L_:„__?_„ . — ^.Xhus 
I find ^—2.72? 
>and therefore a, — .22, which. 22 X 
gives .44 Cubic Inches, and fuppofing a Cube-Inch — 
25 J Grains ) .44X 255 ^^^^ 1 1 1 Grains-weight of Water 
that was gotten up into the Tube in the I'^^Cafe niore than 
in the a^, and therefore theBarofcope requires an Addition 
of 1 1 1 Grains on its Top to fink it with the Levelof the 
Water in the 2^ Cafe more than in the i^'. this upon 
•the finking of the 5 in the conimoo Baroscope only 
• Inch; Now I Grain in this new, Baroicope is nearly as 
• difcernable as -hTnch in the CoiTsnon; aud ihereiorb this 
new Barofcope is more exact than the Common m 
Times. Iiiiniii2 Put 
