BRITOMART CLASS (sixteen in number). Second-class wooden gun-boats of the old-fashioned type, carrying two 64-pdr. pivot-guns. BLAZER CLASS (twenty-four in number). Second-class iron gun-boats, carrying one 10-inch rifle. These vessels are little more than large launches, having a bow decked over with light plates. The gun is mounted on a platform, which itself is supported on heavy screws; these screws, being revolved by steam-power, permit the gun to be lowered down into the hold when going to sea, or raised for fighting. The in-and-out tackles and ammunition gear are manipulated by a small capstan aft. These boats have double screws, and work up to a speed of 7 knots. The Staunch, which is the model from which these gun-boats were built, is smaller, and has a musket-proof shelter at the gun. The others have none. [Illustration: BLAZER.] DEE CLASS (twelve in number). Second-class iron river gun-boats, of a peculiar design. These vessels have twin screws, and are provided with a rudder at each end, the bow-rudder, with its yoke and chains, being entirely unprotected. The hull proper is very low, the side curving sharply inboard above the water-line, almost in cigar shape, to such a degree that the dead-lights slope at an angle upward of about 40°. The deck-rail springs from the upper part of this curve about two feet inside of the water-line, being waist high amidships and rising fore and aft into a curved forecastle and poop musket-proof firing-cover for the guns. Amidships are a musket-proof pilot-house and engine-room. The battery consists of two 64-pdrs. at each end under cover, and firing from four ports each, two fore and aft and two abeam. [Illustration: DEE.] VESUVIUS. Torpedo-boat. This craft, built for sudden attacks with torpedoes, is built very low in the water. The smoke-stack is bent horizontally, running along the deck. The furnace is intended to burn coke in order to suppress smoke. The steam-discharge pipes open under water. She is rigged for projecting Whitehead torpedoes. (See Torpedoes, Part III.) LIGHTNING CLASS. Fast torpedo launches, (See Torpedoes.) ENGLISH GENERAL-SERVICE FLEET (OLD-TYPE STEAM CRUISERS.)