the Force of fired Gunpowder . 
259 
Experiments.! 
Diameter of the 
Cylinder at the 
Fracture. 
Area of a trans- 
verse section of 
the Cylinder at 
the Fracture. 
Weight required to break 
it. lbs. avoirdupois. 
Inch. 
Inch. 
1 . 
50 
5°9,*9 
123.18 
2. 
60 
_i 
l82. 
1000 
353 . 68 
3 - 
66 
1000 
292, 3 
220.75 
4 - 
76 
1000 
2 20, 7 
277.01 
Number of Experiments = 4.) 
Mean 
Weight required to break 
1 inch of this iron, 
lbs. avoirdupois. 
62737 . 
64366. 
64526. 
61063. 
252692. 
63173- 
If now we take the strength of the iron of which the barrel 
was composed as here determined by actual experiments, and 
compute the force required to burst the barrel, it will be found 
equal to the pressure of a weight of 410624^ lbs. instead of 
436800 as before determined. For it is the resistance or force of 
cohesion of 1 inch of this iron to 63173^5., as that of 64- 
inches (the area of the fracture of the barrel) to 4106244- lbs. 
And this weight turned into atmospheres, in the manner above 
described, gives 54750 atmospheres for the measure of the force 
which must have been exerted by the elastic fluid in bursting the 
barrel. But this force, enormous as it may appear, must still 
fall short of the real initial force of the elastic fluid generated in 
the combustion of gunpowder, before it has begun to expand ; 
for it is more than probable that the barrel was in fact burst 
before the generated elastic fluid had exerted all its force, or 
that this fluid would have been able to have burst a barrel still 
stronger than that used in the experiment. — But I wave these 
speculations in order to hasten to more interesting and more 
satisfactory investigations. Passing over in silence a consider- 
mdccxcvii. M m 
