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in the bar almost immediately, so that in the further 
progress of the trial there is no difference between bars 
which were originally either cold or warm. 
If low temperatures have any influence in rendering iron 
weaker or more brittle, the only way in which the amount 
of such influence can be realised is by a sudden impact, 
and the striker’s hammer was the readiest appliance for the 
purpose. In the following experiments great care was 
taken that the blows should be as nearly as possible of the 
same force in each trial, and as the experiments were all 
carefully conducted, and are vouched for by the parties 
named, they may be fairly relied on as representing truly 
the facts of the case. 
(1) William Bouch, Esq., C.E., Engineer of the Stockton 
and Darlington Railway, made the following experiment 
December 29th, 1870, the temperature at the time being 
about 26°, but it had been as low as 19° over night. 
A bar of round iron, l^in. diameter, of best quality, was 
taken from the yard, being then coated with ice ; it had 
been exposed to a week’s hard frost. It was held over the 
edge of a smith’s anvil, and one blow from a 121b. hammer 
by the striker, broke apiece, 4in., long short off, the fragment 
flying twelve yards along the floor of the workshop. The 
same bar was then put into the mouth of a furnace, but not 
in contact with any flame, for a short time, to unfreeze it. 
The heat received into the bar was so moderate that a 
smith could grasp it with his hand. It was then allowed 
to lie on the floor for some time, until it had quite cooled 
down to the temperature of the workshop. It was now 
placed on the anvil, and the same striker as in the flrst 
experiment, with the same hammer, gave fourteen blows 
without causing the slightest fracture, the bar being merely 
bent about two inches. Mr. Bouch adds that he has, in his 
experience, met with many cases nearly as convincing as 
the above. 
