ESSEX COUNTY. 
257 
after annealing the bar, and cooling it off in dry ashes. In attempting to carry the torsion 
beyond this extent, the bar was twisted off at the jaws of the vice, in which the operation was 
performed. 
Having thus proved that this iron is not under any circumstances cold short, I caused the 
bar 11 inches wide, and 0 • 6 inch thick, to be heated to a fair working red heat, and in that 
state bent flatwise over the corner of an anvil, and a right angle exterior and interior to be 
formed f of an inch from the end. The exterior angle remained perfectly sound. On the 
interior, a thin scale only of metal appeared to be corrugated and partly detached from the rest 
of the mass, owing, probably, to a defect in welding; but not the least sign of a tendency to 
fracture was discovered. Another portion of the same bar was heated as before, and three 
inches of it bent over and hammered flat upon the face of the adjacent part. 
Complaints are made by workmen, that much of the iron which they employ will not sus¬ 
tain either of the two preceding operations. They were, however, borne by the iron under 
trial, without evincing any weakness or undue distortion of parts. 
A third test of the quality of this iron, when hot, was afforded by heating about three inches 
near the end of the bar, and driving a steel punch 0 ‘ 8 of an inch in diameter, quite through 
it. This was done without splitting or cracking at the edges, as is too often the case in making 
screw-nuts. Machinists are well aware of the importance of a good material for the forma¬ 
tion of screws and nuts. 
The foregoing trials having, as it was conceived, fully established the freedom of this iron 
from the defects known either as hot shortness or cold shortness, and its softness and mallea¬ 
bility being amply tested by the cutting and hammering incident to these experiments, the 
next step was to determine the absolute force of cohesion, together with the extensibility, when 
subjected to longitudinal strain, and the interior structure of the metal under various circum¬ 
stances, including that of welding in the ordinary way. 
For this purpose, five bars were drawn out and prepared from the specimens already 
described, numbered I., II., III., IV. and V., each about 9 or 10 inches long, 1 inch wide and 
O'2 inch thick. 
No. I., after being reduced to a nearly uniform size throughout its length, was annealed at a red heat, 
and allowed to cool slowly in the air. 
No. II. was hammer-hardened, or beaten with moderate force, throughout its length, until it had been 
for several minutes black, the hammer being occasionally moistened during the process. 
No. III. was forged out and hammered till it was only visibly red in daylight, being left at about the 
temperature at which workmen cease their operations on many of the articles which they produce. 
No. IV., after being brought to an uniform size, was upset for about three inches in the middle, and was 
then annealed and cooled slowly. 
No. V. was drawn out, cut in two in the middle, and welded together; this sample was only 6i inches 
long. 
Geol. 2d Dist. 
33 
