( «o ) 
inner Shell than in the outer Shell, by an Height c- 
qual to a little more than Part of the Height of 
the Barrel above the Water to be rais’d .* And in 
forcing, it is higher in the outer Shell than in the inner 
by a little more than -ri- of the Height of the Pillar of 
Water to be forc’d. And therefore if the Water is 
not required to be rais’d above 64 Feet, the Barrel 
fhould move fb as to make the Middle of its Stroke 
at the Height of 30 Feet, or at the middle of the 
way from the Water to be rais’d, to the Delivery at 
top. 
The 7th Figure drawn by a larger Scale, reprefents 
the three Cylinders, which are here made of Copper 
in their juft Proportions: And for the fake of thofe 
that would confider this matter fully, I have here gi- 
ven their Lengths, Diameters within and without, and 
Thicknefs. - ’ ' 
Outer Cylinder 
or Barrel, Di D2. 
Middle or hang- 
ing Cylinder, in 
which the Stroke 
is made Cl C2 cc. 
Inner Cylinder or 
lug clofed at top 
y a Cap, and mo- 
ving up and down 
with the Barrel to 
which it is joyn’d 
at bottom, dddd. 
Length 
Diameter 
within. 
Thicknefs 
Diameter 
without 
> 
> 
Inches 
-30 
- ^,74 
- 0,10 
- 6,94 
Inches Inches 
—29,0 ■ — — 31,2 
6,35 
<5,03 
0,13 
6,51 
6,29 
Here B B reprefents part of the Elbow of Fig, 
or of the forcing Pipe of Fig, 6 . But as the Spaces 
between the Cylinders are fo fmall, as not to be vi- 
fible even in a large Draught made by a Scale; I 
have here given three more Draughts of the three 
Cy- 
