ESSEX COUNTY. 
259 
Table of Experiments on the Tenacity of the Iron. 
No. of tha bar. 
ei 
o 
o 
« 
w 
V 
a 
‘S 
0) 
04 
0) 
O 
6 
Z 
Area of section before 
trial in square in¬ 
ches. 
Breaking weight in 
lbs. avoirdupois. 
Strength in lbs. per I 
square inch. | 
OBSERVATIONS. 
I. 
Completely 
annealed. 
1 
2 
3 
4 
5 
6 
0.1890 
0.1929 
0.1954 
0.1986 
0.2036 
0.2057 
10175 
10288 
10345.5 
10374 
10972.5 
11029.5 
53820 
53336 
52945 
52235 
53941 
53614 
Length before trial, 10 inches; after, 13-5; total elon¬ 
gation, 35 per cent. Specific gravity after trial, 
7‘685, 7'676, 7-668; mean, 7-676. After the 4th 
fracture, the area of section was 0-1064 inch, in¬ 
stead of 0 • 1986 as at first; diminution 46 per cent. 
Mean strength of this bar, 53311; greatest diffe¬ 
rence, 1706 lbs. = 3-2 per cent, of the mean. 
II. 
Hammer- 
hardened. 
1 
2 
3 
0.1980 
0,2019 
0.2000 
12967.5 
13053 
13399.75 
65492 
64650 
66998 
Length before trial, 9-125 finches ; after, 11 inches; 
total elongation, 20-5 per cent. Specific gravity 
after trial, 7-769, 7-756, 7-779; mean, 7-768. 
Mean strength, 65713; greatest difierence, 2348 lbs. 
= 3-5 per cent, of the mean. 
III. 
Hammered till 
nearly black. 
1 
2 
3 
4 
0.1983 
0.2151 
0.2163 
0.2213 
11970 
12454.5 
12768 
12910.5 
60363 
57919 
59029 
58339 
Length before trial, 9-5 inches; after, 12-25; total 
elongation, 28-94 per cent. Specific gravity, 7-760, 
7-7TO, 7-662 ; mean, 7-750. After the 2d fracture, 
the area of section at the point of fracture was 
0-1176; diminution, 45-2porcent. Mean strength, 
58912; greatest difference, 2444 lbs. = 4-15 per 
cent of the mean. 
IV. 
Upset in the 
centre and 
annealed. 
1 
2 
3 
4 
5 
0.2086 
0.2233 
0.2316 
0.2282 
0.2354 
13110 
13623 
13737 
15162 . 
15561 
62847 
61007 
59313 
66441 
66104 
Length before trial, 9; after, 11-2; total elongation, 
24-46 per cent, of original length. Specific gravity 
after trial, 7-813, 7-731, 7-754, 7-634; mean, 
7-733. Mean strength, 63142 ; greatest difference, 
7128 lbs. = 11 -2 per cent, of the mean. The last 
two results belong to the upset portion of the bar ; 
the thickest part of the upsetting remained, how¬ 
ever, unbroken. 
V. 
Welded toge¬ 
ther near 
the middle, 
hammered 
till nearly 
black. 
1 
0.1845 
10773 
39585 
Broke outside of welding. The strength is about the 
same as in No. III. 
