BURSTING OR HEAVY GUNS. 
179 
With an 85-lb. charge the pressure 
at 6i ft. from bottom of bore should 
not exceed 5J tons, and Captain Noble 
believed that if the projectile were 
immovably fixed with its base there, 
and the charge fired, the gun would 
resist the strain. A shell in motion 
suddenly checked would throw a great 
strain on the gun (Answer No. 484), 
but he considered the wad wholly 
inadequate so to check it. 
The diagram here shown is Captain 
Noble ; s. It is intended to suggest 
the process of fracture. He con¬ 
sidered that certain splinters show 
marks of having been tilted in the 
form of a cone whose base was 
towards the muzzle, and of having* 
in this position been grazed by the 
passage of a projectile over their 
hinder ends. This he could only 
account for on the supposition of a 
charge opening them in front of a 
projectile—that is, on the supposi¬ 
tion that the gun was double loaded. 
Many of us thought that wedging 
was the probable cause of the accident 
before we received the report of the 
Committee. The gas-check unques¬ 
tionably increases the danger of such 
an occurrence; for it prevents the 
imprisoned gas from rushing in any 
considerable quantity past the pro¬ 
jectile, and so finding a safety valve. 
The idea that an air-space formed 
by the projectile slipping in the bore 
was the cause of the explosion was 
dismissed soon, but it constituted 
the third subject to be investigated 
by the Committee of which General 
Gordon is President. 
The opinion in favour of wedging 
which deserves most attention is that 
of Sir William Palliser. He urges 
that in crushing a wad at the very 
high velocity at which the projectile 
is moving, a sufficient resistance may 
be offered to jam the shot, and so to 
burst the gun, and that he has made 
experiments proving that this result 
