ON THE STRENGTH OF PILLARS. 
433 
Table I. (Continued.) 
Length. 
Diameter. 
Mean 
Diameter. 
Deflection 
of middle 
of pillar. 
Corre- 
sponding 
weight. 
Breaking 
weight. 
Mean from 
breaking 
weights. 
Remarks. 
inches. 
20-1666 
inch. 
•785 
inch. 
1-767 
inch. 
lbs. 
lbs. 
7255 
5950 
lbs. 
/Weight 2 lbs. 8-J oz. 
\ Weight 2 lbs. 6 oz. 
20-1666 
•75 
1 6602 * 
15-125 
•50 
•05 
1689 
1801 
1913 
1997 
1801 
15-125 
•50 
•09 
•11 
•31 
•20 
1997 
/ Neutral line well defined. 
[T : C : : 39 : 11. 
[T : C : : 39 : 11 . 
i In this experiment the deflection was taken 
|_ as the pillar was bending. 
15-125 
•50 
•34 
•08 
1857 
1353 
1857 
•50 
•15 
•20 
1689 
1801 
1857 
1904 
15-125 
•77 
10138 
T : C : : 48 : 29. 
T : C : : 53 : 23. 
15-125 
•76 
9746 
7786 
15-125 
•75 
•76 
9223 
T : C : : 49 : 26. 
For the forms of fracture, see g. Plate XV. 
15-125 
•99 
20163 
T : C : : 57 : 42. 
T : C : : 60 : 39. 
15-125 
•99 
19239 
15-125 
•99 
•99 
19855 
19752 
T : C : : 60 : 39. 
For forms of fracture, see i, j, k. Plate XV. 
10-083 
•76 
16683 
1 
10-083 
•76 
} 
16683 
>17506 
/ The two first failed by the ends becoming 
10-083 
•77 
19152 
\ split, by a conical wedge forming at them. 
7-5625 
•51 
6188 
T • C, • • ^1 -90 
7-5625 
•49 
4578 
T : C : : 32 : 17. 
7-5625 
•49 
•497 
5019 
5262 
T : C : : 34 : 15. 
7-5625 
•77 
} -77 
23893 
T : C : : 35 : 42. 
T : C : : 41 : 36. 
7-5625 
•77 
22003 
22948 
These pillars were split at both ends. For frac- 
tures, see l, m. Plate XV. 
3-7812 
•50 
15233 
15107 
'In these two experiments the area com- 
pressed seemed to have been greater than 
the extended area. The ends were split 
by the pressure. For form of fracture, see 
3.7812 
•50 
•50 
14981 
n. Plate XV. 
By the letters T, C are to be understood the versed sines or depths of the neutral 
line on the surfaces submitted to tension or compression ; and the ratio T : C is that 
of those versed sines or depths. The neutral line is not, strictly speaking, a straight 
one, but a curve ; the dimensions are, however, so adapted that it may be considered 
as a straight line. 
The pillars marked with an asterisk were cast after the others, and from the same 
description of iron, but probably a different sample ; some of them were cast in 
green (moist) sand, too, whilst all the rest of the pillars were cast in dry sand. 
In all cases, except otherwise mentioned, the pillars broke nearly in the middle, 
both in this Table and the following one. 
mdcccxl. 3 K 
