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0-3083 
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$ uO>y 
223-23$ 9c* 
/^uf e-c$3 1 Oc »n ets\ 
'/S/0-08 
84, Count Rumford's Inquiry concerning 
lated in the cylinder might from time to time be measured, a 
small round hole, (see d } e , fig. 3.) 0.37 of an inch only in dia- 
meter, and 4.2 inches in depth, for the purpose of introducing 
a small cylindrical mercurial thermometer, was made in it, on 
one side, in a direction perpendicular to the axis of the cylinder, 
and ending in the middle of the solid part of the metal which 
formed the bottom of its bore. 
The solid contents of this hollow cylinder, exclusive of the 
cylindrical neck by which it remained united to the cannon, 
were 385 f cubic inches, English measure; and it weighed 
113.131b. avoirdupois: as I found, on weighing it at the end 
of the course of experiments made with it, and after it had 
been separated from the cannon with which, during the expe- 
riments, it remained connected,* 
Experiment No. 1. 
This experiment was made in order to ascertain how much 
heat was actually generated by friction, when, a blunt steel 
borer being so forcibly shoved (by means of a strong screw) 
against the bottom of the bore of the cylinder, that the pressure 
* For fear I should be suspected of prodigality in the prosecution, of my philoso- 
phical researches, I think it necessary to inform the Society, that the cannon 1 made 
use of in this experiment was not sacrificed to it. The short hollow cylinder which 
was formed at the end of it, was turned out of a cylindrical mass of metal, about 2 feet 
in length, projecting beyond the muzzle of the gun, called in the German language 
the verlorner kopf, (the head of the cannon to be thrown away,) and which is 
represented in fig. 1 . 
This additional projection, which is cut off before the gun is bored, is always cast 
with it, in order that, by means of the pressure of its weight on the metal in the lower 
part of the mould, during the time it is cooling, the gun may be the more compact- 
in the neighbourhood of the muzzle; where, without this precaution, the metal would 
fee apt to be porous, or full of honeycombs. 
