When the thickness of armor-plating increased, gun-makers tried to overcome the resistance by giving greater energy to the shot. As this required large charges of powder and very long guns, muzzle-loaders became impracticable on shipboard, and were supplanted by breech-loaders. From this stage guns developed greatly in power until, in 1882, those designed for the _Benbow_ were to weigh 110 tons, to be 43 feet long and 16¾ inches in calibre, and with 900 pounds of powder and an 1800-pound projectile were to develop 54,000 foot-tons, or an energy sufficient to penetrate thirty-five inches of unbacked wrought-iron at one thousand yards. The guns for the latest English ships, the _Trafalgar_ and the _Nile_, weigh 67 tons, are 36 feet 1 inch in length and 13½ inches in calibre, and with a 520-pound charge and a 1250-pound projectile are expected to develop 29,500 foot-tons, or an energy sufficient to penetrate an iron target twenty-two and a half inches thick at a thousand yards. These results apparently show a retrogression in power, but a comparison of the _Inflexible’s_ and _Trafalgar’s_ batteries proves that the more modern gun of the latter weighs 13 tons less, is 2½ inches smaller in calibre, fires a shot 450 pounds lighter, and yet develops an energy greater by 3000 foot-tons. This gain is mainly due to the improvements made with powder and projectiles. In 1883 a 403-pound Whitworth steel shell penetrated a wrought-iron target eighteen inches thick backed by thirty-seven inches of well-packed wet sand, one and a half inches of steel, various balks of timber, and sixteen feet more of sand. When the projectile was recovered after this stratified flight it was found to be practically uninjured. On the Continent, where breech-loaders were favored earlier than in England or with ourselves, the heaviest rifles afloat are the 75-ton, 16.54-inch calibre, French, and the 106 tons, 17-inch Italian guns. These are, however, not the largest pieces designed, for there is an 120-ton Krupp gun, and the French have projected one which will weigh 124 tons, be 18.11 inches in calibre, and fire a 2465-pound projectile—over a ton—with a powder charge of 575 pounds. A comparison of the Krupp 120-ton gun with the 110-ton Armstrong shows that the former is more powerful; that its projectile is much heavier, and the initial velocity and pressure are smaller. The results at the recent test were as follows: Armstrong. Krupp. Charge 850 pounds 847 pounds. Shot 1800 ” 2315 ” Velocity 2150 feet 1900 feet. Pressure 19.9 tons 18.8 tons. Energy 57,679 foot-tons 67,928 foot-tons.