The _Cocyte_ and _Mitraille_ belong to a new class, or rather they represent a type which, after disappearing for a season of doubt and denial, has had its value so much recognized that three Continental nations are giving it earnest study. A late French Minister of Marine asked within a year for money to construct fifty of these gun-boats, but was then refused the grant, a decision for which Admiral Sir George Elliot thinks England ought to be very grateful. This distinguished officer believes in the value of the type, and hopes that the Admiralty “will take note of the threat thus made” before the theory is allowed to prevail that adequate security can be given to the British coasts by sea-going cruisers, submarine mines, shore batteries, and torpedo-boats. The boats present a small target, and give good armor protection to guns which, when the vessels are inshore or reinforced by land batteries, have sufficient power to keep battle-ships at a distance. They are very handy, have good speed, and are economical, because for the same money they can, as flotillas, bring into the action four times the gun-power possible in the large battle-ships. In France this type is divided into two classes—the _Achéron_, _Cocyte_, _Phlegéton_, and _Styx_, of 1639 tons, belonging to the first, and the _Fusée_, _Grenade_, _Mitraille_, and _Flamme_, of 1045 tons, to the second. The iron and steel hulls are extensively subdivided into water-tight compartments, and are protected by complete belts of steel armor at the water-line, and by arched steel-armored decks. The superstructures above the protective decks have water-line belts of cellulose. The armament consists of one heavy gun mounted in a barbette tower, and of a strong secondary battery of machine guns and torpedoes.