ON THE STRENGTH OF PILLARS 
445 
Table IX. — Hollow Cylinders flat at the Ends. 
Results of Experiments on the Strength of Hollow Cylinders of Cast Iron (Low Moor, 
No. 3.), the ends being turned flat and perpendicular to the sides, and the pressure 
communicated by the approach of parallel surfaces, against which the ends of the 
pillar were firmly bedded. Length of each pillar 7 feet 6f inches, except other- 
wise mentioned. Plate XV. No. 8, A, B, C, and D. 
No. of Experiment. 
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 3-55 
where W = the break- 
ing weight, D, d the 
external and internal 
diameters ; and the 
length of the cylinder 
= 7 feet 6f inches. 
Ratio of the 
thicknesses 
of the ring 
of metal on 
opposite 
sides at 
place of 
fracture. 
Remarks. 
inch. 
lbs. 
lbs. 
lbs. 
i. 
Hollow uniform cylinder, same 
•02 
2813 
When this cylinder was broken, it was 
as in Experiment 1. of the pre- 
•03 
3821 
found that the thinner side was that 
ceding table. 
•00 
unloaded 
which was compressed. This cy- 
inch . 
•05 
4829 
linder was not reduced in its thick- 
External diameter l - 78 
■07 
5837 
ness toward the ends. 
Internal diameter by mea- 1 i .91 
•09 
6845 
The weight of all the cylinders below, 
sure J 
•11 
8861 
whether their lengths are 7 feet 6£ 
Internal diameter by cal- 1 
•17 
10877 
inches, or 7 feet 4f inches, are given 
culation J 
•20 
12001 
for the greater length. 
•30 
14353 
Mean... 1’21 
•42 
15921 
Length of cylinder 7 ft. 4f inches. 
•50 
16705 
Weight (length 7ft. 6§ ins.)311bs. 
•66 
17489 
17840 
2973-7 
1:5 
2. 
Hollow uniform cylinder, same 
•12 
11217 
This cylinder was reduced to half its 
as in No. 2. preceding table. 
•17 
13177 
thickness near to the ends, and to 
External diameter 1‘74 
•32 
15137 
three-fourths of its thickness half 
Internal diameter 1*187 
•48 
15921 
way between the middle and the 
Length of cylinder 7 ft. 4f inches. 
direction 
ends ; hut the weight of the cy- 
Weight of cylinder 7 ft. 6-J inches 
changed. 
linder as set down is for the whole 
= 30f lbs. 
•54 
16313 
before it was reduced. 
16705 
3031-5 
7:11 
The fracture took place in the middle, 
and in another place near to it, hut 
not in the reduced parts. 
3. 
Hollow uniform cylinder. 
bent 
2141 
This cylinder was reduced in the same 
External diameter 1*76 
•03 
2749 
manner as the last, or somewhat 
Internal diameter by mea- 1 
•05 
5437 
more, and the fracture took place 
sure J 
•06 
6333 
at the reduced part, half way be- 
•09 
6677 
tween the middle and one end ; 
•25 
13721 
where the external diameter was 
•36 
15233 
1'60 and the internal 1-18, and the 
•54 
16241 
16745 
2968-7 
1:3 
thickness of the metal on the op- 
posite sides = '09 + - 32 = -41. 
But the thickness of the metal in 
the middle of the pillar was 1'76 
— 1-18 = '58: therefore the re- 
duced part was somewhat less than 
three quarters of the whole. 
4. 
Hollow uniform cylinder. 
•01 
2237 
This pillar was a good sound casting, 
External diameter 1*75 
•05 
4441 
and was not reduced in its thick- 
Internal diameter by mea- 1 
•06 
6569 
ness in the manner of the last two. 
sure J 
•08 
8165 
Internal diameter by cal- 1 
•10 
12445 
culation J 
•12 
13789 
•15 
15133 
Mean... I’ll 
•19 
16477 
Weight of cylinder 32 lbs. 
•25 
17821 
•31 
18493 
•36 
19165 
•42 
19613 
•46 
20061 
•55 
20509 
20957 
3586-9 
1:2 
