446 
MR. HODGKINSON’S EXPERIMENTAL RESEARCHES 
Table IX. (Continued.) 
Description of Pillar. 
Deflection. 
Weight 
producing 
the de- 
flection. 
Breaking 
weight, or 
that with 
which it 
sunk. 
Value of x from for- 
mula 
W 
D 3-55 _ d 3-55’ 
where W= the break- 
ing weight, D, d the 
external and internal 
diameter ; and the 
length of the cylinder 
= 7 feet 6| inches. 
Ratio of the 
thicknesses 
of the ring 
of metal on 
opposite 
sides at 
place of 
fracture. 
inches. 
Hollow uniform cylinder. 
External diameter 2’04 
Internal diameter bymea- ] 
sure J 
Internal diameter by cal- 1 ^ 
culation J 
Mean... 1’46 
Length of cylinder 7 ft. 4-J inches. 
Weight of cylinder 7 ft. 6f inches 
= 35§lbs. 
inch. 
•04 
•05 
•07 
•08 
•10 
■12 
•15 
•17 
•20 
•26 
•37 
•52 
lbs. 
3589 
7387 
11091 
14703 
17391 
20011 
23481 
25105 
26729 
28353 
29977 
31601 
lbs. 
32413 
3573-8 
1 : 1 
6 . 
Hollow uniform cylinder. 
External diameter 2'01 
Internal diameter bymea- 1 J.33Q 
sure j 
Internal diameter by cal- 1 , 
culation f 
Mean... 1*368 
Length of cylinders 7 ft. 6;} ins. 
Weight of cylinder 37f lbs. 
Hollow uniform cylinder, same 
as No. 3. of Table VIII. 
External diameter 2'01 
Internal diameter by mea- 1 
sure J 
Internal diameter by cal- 1 
culation j 
•03 
•05 
•07 
•08 
•00 
•14 
•20 
•27 
•38 
•53 
3589 
5819 
12091 
18667 
unloaded 
21857 
25105 
26729 
28353 
29977 
30789 
3290-3 
7:10 
bent 
bent 
•10 
•01 
•14 
•25 
4251 
5819 
21857 
unloaded 
25917 
27541 
28353 
3214-8 
5: 11 
Mean... 1'415 
Length of cylinder 7 ft. 4f inches. 
Weight of cylinder 7 ft. 6£ inches 
= 36-albs. 
Hollow uniform cylinder. 
External diameter l - 99 
Internal, both by measure 1 ^.3 j 
and calculation J 
Length of cylinder 7 ft. 5-8 ins. 
Weight of cylinder 7 ft 6f inches, 
before reduction 39 lbs. 
bent 
• 02 ? 
•20 
•26 
•33 
•45 
•55 
•90 
1456 
3355 
15605 
17755 
19905 
22055 
24205 
26731 
27067 
2988-3 
6:7 
Remarks. 
This column was not reduced in thick- 
ness as above ; it was a good cast- 
ing, of equal thickness on all sides. 
A wedge broke out at the place of 
fracture which was 4f inches from 
the middle, and showed that the 
ver sin, or depth of the part in a 
state of tension, was 1*72 inch; 
.•. depth of compressed part = 2 04 
— 1-72 = -32 inch. See W. (Plate 
XV., No. 8, D). 
This cylinder had a slight bubble in 
the place of fracture, which it was 
conceived had little influence on 
the strength. The ends of the cy- 
linder were not reduced. 
This cylinder was the same as that iu 
Experiment 3. of the last Table. It 
was rendered quite straight, and its 
ends were firmly bedded against the 
crushing surfaces. Previous to this 
experiment, however, the cylinder 
was reduced to half the thickness 
near to the ends, and to three quar- 
ters of the thickness half way be- 
tween the middle and the ends. 
In the former cases, where the cy- 
linder was reduced, the fracture took 
place only in the middle, but in this, 
the pillar broke both in the middle 
and at the two reduced places half 
way between the middle and the 
ends. It was broken too at the re- 
duced part near to one end, and the 
other end was split. Casting mo- 
derately sound ; the thicker side of 
the casting was the compressed one 
in this instance. 
This cylinder was reduced in the man- 
ner of the preceding ones. It bent 
upwards of an inch, and then broke ; 
first at a small flaw near the middle, 
then at the reduced part half way 
between the middle and one end. 
A piece broke off at the neutral line ; 
it was nearly straight across in a 
line with the inner diameter. Depth 
of compression = '36 inch. 
