420 
MR. HODGKINSON’S EXPERIMENTAL RESEARCHES 
short cylinder one inch in diameter, since the crushing force is as the area of the sec- 
tion, as I have shown*. 
Transverse Strength of the same Iron {Low Moor , No. 3.). 
56. To determine this, the results from two square bars placed upon horizontal 
supports, four feet six inches asunder, and broken by weights suspended from the 
middle, are given below. 
First Experiment. Depth of bar 1-002 inches. 
Breadth of bar 1-004 inches. 
Second Experiment. Depth of bar 1-005 inches. 
Breadth of bar -996 inches. 
Weight. 
Deflection. 
Deflection. 
Load removed. 
W eight. 
Deflection. 
Deflection. 
Load removed. 
lbs. 
inch. 
inch. 
lbs. 
inch. 
inch. 
28 
•069 
• 002 ? 
28 
•060 
56 
•145 
•006 
56 
•141 
•005 
112 
•307 
•020 
112 
•321 
•030 
224 
•677 
•07 
224 
•725 
336 
1-143 
•17 
336 
1-230 
392 
1-413 
•26 
392 
1-550 
448 
1-742 
•38 
448 
1-910 
461 
broke. 
473 
broke. 
The weights were increased toward the last by about 7 lbs. at a time. The modulus 
of elasticity in lbs. per square inch, obtained from the deflection caused by 1 12 lbs. is, 
From the first experiment 14,251,950") 
From the second experiment 13,585,530 J 
13,918,740 Mean. 
Specific Gravity of the same Iron. 
57. This, from the results of six experiments, is as below : 
7122 from cylinders three-fourths of an inch diameter. 
7135 from cylinders three-fourths of an inch diameter. 
7034 from cylinders three-fourths of an inch diameter. 
7090 from cylinders half an inch diameter. 
6977 from cylinders half an inch diameter. 
6952 from a hollow cylinder. 
Mean 7052. 
Pillars of Wrought Iron , Steel, and Timber. 
58. The experiments upon these, which are given in Tables XII. and XIII., are 
similar in their objects to those upon cast iron, but much more limited in their 
extent. They were made, indeed, principally to confirm views which presented 
themselves during the experiments upon cast-iron pillars. 
* Transactions of the British Association, vol. vi. before alluded to. 
