ON THE STRENGTH OF PILLARS. 
443 
Table VIII. (Continued.) 
No. of Experiment.! 
Description of Pillar. 
Deflection. 
Weight 
producing 
the de- 
flection. 
Breaking 
weight, or 
that with 
which it 
sunk. 
Value of jc from for- 
mula 
«- w , 
D 376 — d 3 76 
where W = the break- 
ing weight, and D, d 
the external and 
internal diameters. 
Remarks. 
7. 
inches. 
Hollow uniform cylinder. 
External diameter 2-24 
Internaldiam. bymeasure 1 ' 5 8 
inch. 
■ 01 ? 
•02 
•05 
•09 
•17 
•21 
lbs. 
2141 
4325 
6341 
11169 
13129 
13521 
lbs. 
13913 
lbs. 
917-62 
After bearing 6341 lbs. the pillar was unloaded 
and returned to -00 deflection. This pillar 
was reduced to half its thickness near to the 
ends, and to three-fourths half way between 
the middle and each end ; but it did not fail 
through this, and sunk by flexure, the curva- 
ture being greatest in the middle, as in other 
cases. 
8 . 
Hollow uniform cylinder. 
External diameter 2 - 49 
Internaldiam. bymeasure l - 89 
Internal diameter by cal- 1 , „„ 
culation J 
bent. 
■ 01 ? 
•02 
•04 
•00 
•19 
•40 
•52 
3355 
4123 
6139 
10171 
unloaded. 
16115 
18623 
19239 
19855 
996-24 
This pillar was reduced in the same way as the 
last. When broken, which took place eight 
inches from the middle and not at the "re- 
duced parts, it showed that the ver sin, or 
depth of tension, was to that of compression 
as 19 : 6 nearly. The casting w'as very good, 
and the core in the middle. 
Mean... 1-89 
Weight of pillar 48f lbs. 
9. 
Hollow uniform cylinder. 
External diameter 2-47 
Internaldiam. by measure 1 ■ 99 
Internal diameter by cal- 1 
culation J ‘ 
• 01 ? 
•02 
•23 
•32 
•62 
3211 
8553 
17391 
18029 
18667 
19003 
1123-5 
Variation of thickness of metal at place of frac- 
ture 7 : 9. 
Mean... 1-98 
Weight of pillar 41 lbs. 
10 . 
Hollow uniform cylinder. 
External diameter 2-46 
Internal diameter by mea- 1 ^.g- 
bent. 
• 01 ? 
•02 
direction 
altered. 
•04 
•09 
•14 
•28 
•40 
•49 
•65 
2141 
4581 
7241 
9103 
12445 
14359 
16487 
17551 
18083 
18615 
19147 
989-95 
It broke at a part rather unsound, 13J inches 
from the middle. The thicknesses of the metal 
on opposite sides, at the place of fracture, were 
as 3 : 4. 
Internal diameter by cal- 1 . . 
culation J 
Mean... 1-855 
Weight of pillar 49 lbs. 
11 . 
Hollow uniform cylinder. 
External diameter 2-73 
Internaldiam. by measure 2-14 
Internal diameter by cal- 1 9 . 9n 
culation J 
bent. 
• 01 ? 
direction 
altered. 
•03 
•05 
•40 
•70 
3603 
8185 
12105 
16025 
21219 
22787 
23963 
949-48 
Whenbroken, the cylinder was somew hat thinner 
on one side than the other, and the thin side 
was that which was compressed ; as was the 
case in most of the instances where the cy- 
linders were not equal in thickness at both 
ends. 
Mean... 2*17 
Weight of pillar 48 lbs. 
12 . 
Hollow uniform cylinder. 
External diameter 2- 74 
Internal diameter by mea- 1 2-14 
•02 
•05 
•07 
•08 
•14 
•37 
•62 
110 
3603 
8185 
12105 
16025 
21219 
25139 
26707 
27491 
27883 
1059-5 
This broke three inches from the middle, and a 
crack showing the neutral line gave the ver 
sin of the part submitted to tension = 1-76 
inches. Variation of thickness of metal at 
place of fracture 2 : 3 nearly. 
Internal diameter by cal- 1 g.y- 
culation / 
Mean... 2-155 
Weight of pillar 511 lbs. 
13. 
Hollow uniform cylinder. 
External diameter 3 - 01 
Internaldiam. by measure 2-45 
Internal diameter by cal- 1 „ r . 
culation } 2-51 
•07 
•14 
•23 
•30 
•44 
•75 
16115 
18667 
21219 
22787 
24355 
25923 
26707 
819-46 
This casting was allowed to break, and the 
thicknesses of the metal at opposite sides of 
the place of fracture were as 9 : 15. The thin 
side was the compressed one. The depth or 
ver sin of compression was to that of exten- 
sion as 1 : 5. 
Mean... 2-48 
Weight of pillar 501 lbs. 
3 l 2 
