The steel partially protected cruiser _Charleston_ is, except in details of internal accommodations, a duplicate of the _Naniwa-Kan_, which was in turn a progressive development of the type-making _Esmeralda_, inasmuch as she has greater speed, more powerful armament, and superior protection to stability. The plans of the _Charleston_ were bought abroad simply because they could not be made here; and notwithstanding the twopenny-ha’penny criticisms this action evoked, its wisdom has been justified. The _Charleston_ has neither poop nor forecastle, and the unhampered ends give in action perfect freedom of fire for two 10-inch guns, which are mounted in low, thin-plated barbettes, situated on the ship’s middle line, at a distance of sixty feet from the bow and stern respectively. These pieces are without armor protection, except that offered against machine-gun fire by a two-inch segmental shield. Between these heavy guns a high waist stretches amidships, in which six 6-inch breech-loaders are mounted on sponsons or in projecting turrets. The secondary battery includes two 6-pounder rapid-fire guns, eight machine guns, and four above-water torpedo-tubes. The 10-inch guns must always be brought back to the fore-and-aft line for reloading, and their ammunition is passed through steel tubes which extend below the protective deck. The engines are double-compound, situated in separate compartments, and in the _Naniwa-Kan_ the type developed 7650 horse-power and 18.9 knots. In the twin-screw cruiser _Baltimore_ a longitudinal water-tight bulkhead joins the double bottom, which runs under the engine and boilers to a protective deck that extends the whole length of the ship, and is three inches thick on the flat top and four inches thick on the sloping sides. The machinery consists of a pair of triple-expansion compound engines which are to develop 18 knots and 7500 horse-power with natural, and 19½ knots and 10,750 horse-power with forced, draft. There are two separate engine-rooms and two boiler-rooms, and the normal coal capacity of 600 tons will be sufficient for 1800 knots. Additional space is provided for 300 tons more, and with this total there ought to be an endurance of 8000 miles at 11 knots, and of 14,000 miles, or 75 days’ steaming, at 8 knots. No sails except storm-sails will be provided. The _Baltimore_ is to have a poop and forecastle, on which four 8-inch guns with direct fore-and-aft fire will be mounted. On the main deck six 6-inch guns will be carried in broadside, and the secondary battery and torpedo-tubes are effective and well disposed.