IN BEAMS SUBJECTED TO TEANSVEESE STEAIN. 
467 
Summary of Experiments on Transverse Strength. Compound Sections. 
Length of bearing 48 inches. 
Number and form of section. 
Total 
depth. 
Depth of 
metal in 
flanges. 
Distance 
between 
flanges. 
Breadth of 
flanges. 
Breadth of 
middle rib. 
Total 
breadth. 
Sectional 
area. 
Breaking 
weight. 
No. 15. 
in. 
1- 97 
2- 00 
2-01 
2-08 
2*07 
2*07 
2-06 
in. 
•99 
1-00 
1-01 
Ml 
1*06 
1*02 
1-04 
in. 
•98 
1-00 
1-00 
•97 . 
1-01 
1-03 
1-02 
in. 
1-44 
1-50 
1-54 
1-54 
1*50 
1-57 
1-56 
in. 
•55 
•47 
•48 
•53 
•52 
•47 
•53 
in. 
1-99 
1- 97 
2- 02 
2-07 
2-02 
• 2-04 
2-09 
sq. in. 
2-51 
2-47 
2-52 
2-81 
2-67 
2-57 
2-71 
lbs. 
3310 
.3560 
3735 
3910 
4528 
4563 
4423 
Mean 
2*04 
1-03 
1-00 
1-53 1 -50 
2-03 
2-60 
4004 
Number and form of section. 
Total 
depth. 
Depth of 
centre rib. 
Breadth of 
flanges. 
Breadth of 
centre rib. 
Total 
breadth. 
Sectional 
area. 
Breaking 
weight. 
No. 16. 
in. 
1-97 
1- 96 
2- 05 
2-04 
2-06 
2-05 
2-05 
in. 
•30 
•48 
•55 
•31 
•50 
•50 
•32 
in. 
•98 
1-00 
MO 
1-02 
D06 
1-02 
1-04 
in. 
1-00 
•96 
•92 
1-00 
•98 
1-02 
1-00 
in. 
1-98 
1- 96 
2- 02 
2-02 
2-04 
2-04 
2-04 
sq. in. 
2-43 
2-42 
2^76 
2-39 
2-67 
2-60 
2-63 
00 00 00 GO O 00 GO 
Mean 
2-02 
•51 
1-03 
•98 
2-02 
2-59 
2569 
The neutral axis ha\ing been shown in my former paper to be in the centre of gravity 
of the section, we are enabled to test the accuracy of the existing theory, by comparing 
the resistance at the outer fibres or particles of each of the forms of beam, calculated 
upon that theoiy, with the actual tensile strength of the metal obtained by direct expe- 
riment. 
In any bar or beam, supported at the ends and loaded in the centre, — 
Let /"represent the ultimate tension*, 
I the length, 
W the weight applied in the centre, 
d the depth, 
and X any variable distance from the neutral axis. 
fx . 
Then will be the tension at the distance x, and according to the principle of Leibnitz, 
the sum of all these resistances at the moment of rupture will be 
* In those materials in which the resistance to compression is less than that of tension, f must be taken 
to represent the ultimate resistance to compression. 
3 p 2 
