BURSTING OF HEAVY GUNS. 
181 
place. The 38-ton gun taken from the “ Thunderer ” was loaded in 
the Arsenal in the same way as its fellow which burst on board ship, 
supposing the latter to have failed to fire at the electric discharge; 
that is to say, the second gun was double-loaded in the following 
way:—First, with a 110-lb. battering charge of pebble powder, and a 
688-lb. Palliser projectile and wad; then over that with an 85-lb. 
charge, and 575-lb. common shell and wad; and in this condition it 
was fired, pressure gauges being employed on the base of each pro¬ 
jectile and in the bottom of the bore. 
The gun so fired burst in front of the trunnions, very near the same 
spot as its fellow. A general resemblance, however, might be due to 
the fact that both guns, in common with other Fraser guns of the 
same type, are very strong about the breech; so that any strain 
suddenly brought upon the piece when the projectile was some 
distance forward might so far resemble the action of a charge fired in 
an advanced position that the gun might yield in both cases at its 
weaker part. Evidence, then, is needed to identify the two burst guns 
as exactly as possible in detail. The principal points of the material 
evidence on which the conclusion of the Committee appears to be 
chiefly based are the following :—(1) The indication of great pressure; 
(2) the position of the fracture; (3) certain indications in the form of 
abrasions of a projectile in the bore; (4) evidence furnished by a stud 
picked up in the turret. Let us consider these in detail, and see 
whether a close and convincing correspondence in the case of both 
guns is to be found. 
(1) In the Steel Tube .—An indication of great pressure cannot possibly 
fail to be found in the case of the Arsenal experiments; the question 
is whether in its nature it corresponds to that in the gun burst on 
service:— -(a) The maximum expansion of the powder-chamber in the first 
gun was about 0*033 in.; in the second gun the expansion at 2 ft. 6 ins. 
from the bottom of the bore was *004 in. horizontally and *006 in. 
vertically, (b) The maximum expansion is at 5 ft., where it is *093 in. 
horizontally and *088in. vertically; the tube of the first gun at from 
30 ins. to 54 ins. from the bottom of the bore is in an ordinary state, but 
from 54 ins. to the fracture—at about 72 ins.—it is bell-mouthed, the 
diameter increasing until nearly six-tenths of an inch is reached at the 
edge of the fracture ; the expansion is nearly all in the grooves, which 
are widened in some parts two-tenths of an inch. The second gun is 
incapable of measurement at 72 ins., being broken off short of that point. 
A precise comparison of the above is impossible, because the expansions 
in the first gun are taken with reference to original dimensions, while 
those in the second gun are due to this one round. In both cases there 
is a bell-mouthed or conical enlargement which corresponds as fully as 
could be expected, (c) At a point 69 ins. from the bottom of bore of 
the first gun is a smooth mark for 6 ins. near the lowest portion of the 
circle where the projectile was pressed. The interior of the barrel of 
the second gun cannot be examined as to this at present, being built on 
to a wood spindle, (d) Two longitudinal cracks in the first gun run 
from point of rupture for a foot to the rear, and then transversely. 
