586 
ROTATION FOR STABILITY OF 
Therefore 
A + C 
C 725 
2971 
3696 
y = 
2^ “ 5942 * 
log a = 
3-4729027 
— 3-5677320 
= 
1-9051707, 
a = 
0-80385, 
log y = 
2-8603380 
and 
Now, 
— 3-7739326 
= 1-0864054, 
y = 0 - 12201 , 
a — y = 0-68184. 
_ weight of the displaced air 
weight of the shell 
and the density of cast-iron is 7*207 times the density of water, while 
the density of air at 15*5° 0. or 60° F., the height of the barometer 
being 30 ins., is of the density of water; therefore 
P _ _ 
<j 4 
f * SIS 
(>-S) 
x 7*207 
27 
19 x 7-207 X 816 
log 27 = 1*4313638 
1- 2787536 
0-8577545 
2- 9116902 
log 19 = 
loo- 7-207 = 
log 816 = 
logt = 
(T 
1-4313638 
— 5-0481983 
= 4-3831655, 
c = 0 00024164, 
cr 
and therefore ^ is a fraction small enough for the squares and higher 
powers to be neglected; and therefore 
7T% 4 
4 a 2 /q 2 - (a — y) 
