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Minister of Marine, it must be attributed to the fact that the maximum 
pressure of the gas upon the unit of surface of this piece with a charge of 
44 lbs. of pellet powder and spherical balls, is sensibly less than in the gun of 
8'58 inches with the charge of 27*5 lbs. of common powder. 
14. “The practice at the 4*7-inch armour plates has given this result: 
That spherical steel shot (of 200 lbs.) projected by a charge of 44 lbs. of 
pellet powder are capable of penetrating such a cuirass at a distance of 934 
yards, but the accuracy of fire was much less than that of the rifled 8*58 
inch gun. The target was formed by two plates superposed, presenting a 
mark of 12ft. lOins. in width by 6 ft. high: out of eighteen shots only 
three struck it. 
15. “ Recapitulating the result of the experiments we arrive at the 
following conclusions 
(1) “ That Krupp's cast steel cannon are of very great resistance. 
(2) “ That rifled guns possess very important advantages over smooth-bored 
guns of the same weight firing also spherical projectiles of the same weight, 
as regards their effect on/ armour plates. 
“This superiority of rifled cannon over smooth-bores rests on the fact 
that their accuracy is much greater, and that elongated shot of.a given 
weight produce more effect on iron plates than spherical shot of the same 
weight. 
(3) “That rifled cannon of steel, of large calibre, muzzle-loading, and 
in which the escape of gas by windage is allowed, are not well adapted for 
settling the question proposed, in a manner which shall be quite satisfactory; 
inasmuch as they are subject to a rapid wear of the metal, for which reason 
we cannot assign with certainty a longer duration than 250 rounds for a 
cannon of this description. 
16 “Such being the state of the case, it was no longer difficult to 
determine what course to take to throw more light on the question of the 
proper guns to oppose to a fleet of armoured vessels. 
“ It was necessary, 
(1) “ To give the preference to rifled guns over smooth-bored. 
(2) “To set on foot fresh experiments with the former in order to find 
means of remedying the very serious inconvenience resulting from the liability 
of the metal in the bore to wear. 
17. “To this effect two series of experiments have been taken in hand. 
The first was concerned with muzzle-loading guns firing projectiles with 
expanding bottoms of copper (culots), .These are intended to close the space 
between the projectile and the bore and thus prevent the escape of gas. 
The second series had reference to breech-loading guns. 
“The projectiles with expanding bottoms of copper were tried in two 
guns. 
