THE BOYAL AETILLEEY INSTITUTION. 
303 
«ON THE CHANGE OP POEM ASSUMED BY WEOUGHT-IEON AND OTHEE 
METALS WHEN HEATED AND THEN COOLED BY PAETIAL IMMEESION 
IN WATEB.”* 
By Lieut.-Col. H. CLEBK, K.A., F.R.S. 
Origin of the Experiments, 
A short time ago, when about to shoe a wheel with a hoop-tire, to which 
it was necessary to give a bevel of about fths of an inch, one of the work¬ 
men employed suggested that the bevel could be given by heating the tire 
red-hot and then immersing it one-half its depth in cold water. This was 
tried, and found to answer perfectly, that portion of the tire which was out 
of the water being reduced in diameter. The tire was 3 inches wide, ^-inch 
thick, and 4/ % rf in diameter. 
As this result was curious and not generally known, I considered it 
desirable to institute some further experiments in order to try how far, by 
successive heatings and coolings, this change of form could be augmented, 
and also whether the same effect could be produced on other metals than 
wrought-iron. 
Mode of carrying out the Experiments, 
The experiments were made on cylinders of wrought-iron of different 
dimensions, both hollow and solid; immersed, some to one-lialf of their 
depth, others to two-thirds; also on similar cylinders of cast-iron, steel, zinc, 
tin, and gun-metal. 
The specimens experimented on were all accurately turned in a lathe to 
the required dimensions, which were carefully noted; they were then heated 
to a red heat in a wood-furnace used for heating the tires of wheels. As 
soon as they had acquired the proper heat, they were taken out and immersed 
in water to one-half or two-thirds of their depth (as stated in the experi¬ 
ment). The temperature of the water ranged from 60° to 70° Fahr. 
The specimens were allowed to remain in the water about two minutes, in 
which time the portion in the air had lost all redness, and that in the water 
had become sufficiently cool to handle. These alternate heatings and cook¬ 
ings were repeated till the metal showed signs of cracking or giving way. 
The dimensions were noted after every five heatings. The circumferences 
were measured in preference to the diameters, as the true circular form was 
liable to alter. 
* This paper is reprinted from the “Proceedings of the Boyal Society;” and the Committee 
have to acknowledge the kindness of the President and Council in granting the use of the blocks 
for the wood cuts. 
[VOL. III.] 
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