182 
BURSTING OF HEAVY GUNS. 
Two longitudinal cracks in the second gun run from point of rupture; 
one starts at top, takes a spiral direction, and ends at “ down,” nearly 
opposite the vent; the other runs longitudinally for about 2 ft. The 
general direction of cracks in both cases corresponds, but the second 
gun has suffered decidedly more than the first, (e) There is no appear¬ 
ance of jamming or seizure on the slot of the bore of the first gun, but 
grooves widened for 18 ins. from point of rupture. The second gun 
agrees generally with this for the length corresponding to the portion 
left of the first gun; at 10 ft. ins., however, commences a series 
of violent abrasions, which continue for about 3J ft., ending with a 
tremendous scoop, where steel is scraped off, and the muzzle part of the 
tube for about 2 ft. 5 ins. broken off entire. 
In the first gun are three pieces of barrel about the bottom of the 
circle, at about 6 ft. from the bottom of the bore, showing marks in¬ 
dicating that the projectile was passing over them when rupture took 
place; and at from 9 ft. 7 ins., 10 ft. 6 ins., and 11 ft. and 11 ft. 9 ins. 
are four or five marks of striking from the projectile. No portion of 
the steel tube is recovered beyond 12 ft. 2 ins. from the bottom of the 
bore. The most striking marks begin about where the steel barrel 
becomes its minimum thickness, and run on from there—that is, at about 
10 ft. 6 ins. from the bottom of the bore. Here, then, is all the corres¬ 
pondence that could be reasonably looked for. 
Next, as to resemblance in the fracture of the exterior coils. Figs. 1 and 
2 give the horizontal projection of the guns, looking down on them, and 
Figs. 3 and 4 give the guns turned over so as to show the under sides. 
The parts shaded flat in 1 and 3 are deficient, owing to the fragments 
having gone overboard. Figs. 2 and 4 appear to be broken into smaller 
pieces, but if the fragments corresponding to those lost in 1 and 8 be 
shaded and left for after consideration, the comparison of the action of 
the two guns can be better made, and a close resemblance may be traced 
in the manner of breaking up. To commence at the breech, the second 
gun's C coil is cracked in a longitudinal line (shown in Fig. 4), also there 
is a ring fracture running round nearly the entire circumference in front 
of the trunnions, which fractures are not found on the first gun, but 
there is on that a ring fracture within a foot of the same place, running 
completely round the “ 1 B coil.” There is, then, a measure of similarity 
in the guns having parted in a ring fracture near the same place—that 
is, nearly at the place where the B and C coils hook on to each other. 
In one case the C coil has yielded and the B has stood; in the other 
the B has yielded and the C has stood. In this, of course, is a distinct 
difference. The C coil ought to be the stronger; still, if from any cause 
it should be the weaker of the two, the same strain on a gun which 
might ordinarily tear the B coil might then find relief in tearing the C 
in preference. There is, of course, the alternative suggestion that the 
pressure took place further forward in the first gun than in the second 
one. This, indeed, is the main point on which Sir William Palliser 
argues that the first gun was not burst from the same cause as the 
second. The effect on the breech portion of the second gun was 
undoubtedly greater, as shown by the longitudinal cracks, and the 
position of the ring fracture was .further back. Admitting these features. 
