or OLASS, ANT) THE EESISTANCE OF GLASS VESSELS TO COLLAPSE. 
243 
Table X. — Kesults of Experiments on the Eesistance of Glass Globes to External 
Pressure. 
Number of 
experi- 
ment. 
D. 
k. 
P 
by expe- 
ment. 
P 
by formula 
(9). 
Proportional 
error by 
formula. 
I. 
5-03 
•014 
292 
292 
0 
II. 
3-08 
•018 
410 
408 
1 
TuTJ 
III. 
4-93 
•022 
470 
580 
4-1 
-r 4 
IV. 
3-6 
•020 
475 
340 
1 
4 
V. 
8-22 
•010 
35 
35 
0 
VI. 
8-2 
•012 
42 
44-8 
VII. 
8-2 
•013 
60 
61-3 
VIIT. 
4-0 
•024 
900* 
1370 
IX. 
4-0 
•023 
900* 
1450 
X. 
6-0 
•039 
1000* 
1218 
. . » 
XXIII. 
3-02 
•0123 
21 2t 
238 
+i 
The lengths of the cyhnclers of Experiments XI., XII., and XIII. are the same, and 
their diameters are nearly equal to one another. The same observation applies to the 
cylinders of Experiments XIV. and XV., and also to Experiments XVI. and XVII. In 
order, therefore, to reduce the pressures p to uniformity of diameter, we may assume, 
for such small differences, that D varies as i. These reductions being made, we may 
obtain the following Table : — 
Table XI. — Peduction of the Results of Experiments on Glass Cylinders 
to uniformity of Diameter, &c. 
Number of 
experiment. 
D. 
Diameter, 
in inches. 
L. 
Length, 
in inches. 
V- 
P reduced to unity 
of thickness. 
p D L. 
11, 12, 13. 
3 
14 
24-81 
1042 
14, 13. 
4-05 
7 
40-63 
1151 
16, 17. 
4-05 
13-8 
22-67 
1260 
18. 
3-98 
14 
22-33 
1240 
Mean value of p L D = 
^ 1173 
Here the contiaued product of the pressure, diameter, and length is shown to be very 
nearly a constant quantity, the thickness of the glass being the same, that is for k—'O!. 
Hence we have 
- 01 “ 
( 11 .) 
Now the mean value ofp D L is 1173, as shovra in Table XI., and a=l‘4, as deter- 
* Eemained unbroken. 
t Green glass. 
