66 
MINUTES OF PROCEEDINGS OF 
particular attention was given to the centering of the shot after the studs 
had been applied. 
“The result of these experiments was that steel projectiles of 8*58 inches 
fired from this gun have fairly passed through iron plates of 4*7 inch 
thickness. 
“ The practice was extremely accurate. The point aimed at was struck 
with certainty at 233 yards. After obtaining these perfectly satisfactory 
results, the trial of endurance was proceeded with. The charge was 33 lbs. 
of pellet powder, and for economy sake cast-iron shot were used. The gun 
(B) burst at the 109th round; the projectile did not reach the butt, and was 
itself picked up in pieces. 
“ The fragments of the shot and of the burst gun were examined with 
care. It resulted from this examination that the gun in all probability 
burst from the effects of the previous breaking up of the shot, and that the 
fragments of the projectile produced a stoppage in the bore.* 
9. “Although the marks on the fragments of the shot and of the gun 
were such that it might be concluded that the bursting of the gun was 
caused by the breaking up of the projectile in the bore, these marks did not 
altogether explain the result, or account for the previous movement of the 
projectile in the bore. 
“Their character was not so distinct as that of the markings of the first 
gun; and this circumstance gave room for the advancing of opinions by 
certain parties in respect to the accident, which have not been confirmed by 
facts. Some persons conceived doubts as to the resistance of large steel 
guns in general, quite apart from the fact that they were themselves 
convinced by the examination of both the burst guns that the metal em¬ 
ployed was of exceptional quality—of great tenacity, the steel homogeneous, 
and the forging perfectly uniform. 
“Others attributed the bursting of the gun to the system of grooving, 
but facts afford no confirmation to this opinion. 
10. “To set at rest these questions and these doubts, and to arrive at 
some final conclusions respecting guns of large calibre, it was determined to 
try four guns. 
(1) “Two guns (C, JD), of 8*58 inches, one, a rayures par alleles, the other 
rifled on the Trench system, that is to say, with simple grooves contracted 
at the seat of the sliot.f 
“The object in view in trying these guns was to determine their endurance 
under the fire of steel projectiles which cannot break in the bore. The 
experiment was calculated at the same time to illustrate the influence of 
the system of rifling on the resistance on the piece. 
* “ Y avaient jyroduit un obturation .” The official reader is referred for details to the Journal 
of the Commission, No. 9 for 25 March, 1864*. 
f Thd French translation is here as elsewhere somewhat obscure: “a rayures normales par 
rapjoort a la surface de fame avec aretes de sortie ou de cloture des rayures .” 
