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HOWELL'S vSTEAM VKSSKLvS AND MARINE ENGINES. 39 the front of the boilers. There are in each boiler 241 3inch tubes, each being S feet 4 inches long. The boilers are surface blown at night and blown off from the bottom each morning, and each week one is opened and cleaned, ,so that each boiler receives a cleaning and internal inspection once in six weeks. The oil from the main bearings, guides, etc., is collected in a pit beneath the low-pressure C3'linder, passed through a Perfection purifier, and used over and over again. The coal bunker is between the engine and boiler-rooms, and the coal is discharged from the bunker into buckets suspended from overhead tracks, upon which they may be passed to any part of the fire-room. See's ejector is used for discharging the ashes. The boilers are fitted with heaters for promoting circulation in those portions which lie below the level of the grates. The following additional details will be of interest. The air-pump is 26 inches in diameter by 13 inches stroke. The crank shaft is of wrought iron, built up, 11 inches in diameter, the crank pins being of the same diameter and 12 inches long. Two of the main journals are 16 inches in diameter, the remaining four being 14 inches. Thickness and breadth of low-pressure crank web, 9 1/2 inches; of intermediate, 8 1/2 high-pressure, 6 1/2 There are five thrust collars on each shaft, 1 3/4 inches wide, spaced 4 3/8 inches apart, with an outside diameter of 18 inches inside diameter, 10 3/4 inches. Each condenser has 1,036 tubes, 3/4 of an inch by 16 feet, giving a cooling surface of 3,242 square feet to each condenser. Power.

BOSTON AND GLOUCESTER Line Steamer Cape Ann.— Constructed by the Neafie & Levy Ship and Engine Building Co., Philadelphia, Pa.

Engine of the Whaleback Steamer Christopher Columbus.

This engine was built by Samuel E. Hodge & Co., of Detroit, Mich., for the World's Fair passenger steamer Christopher Columbus, constructed at the yards of the American Steel Barge Company, West Superior, Wis. Engine, 26, 42 and 70 by 40 inches. The high-pressure cylinder is fitted with a piston valve, and the low and intermediate with double ported slide valves, the port openings being ample for a piston speed of 770 feet per minute. None of the cylinders are jacketed, but the high-pressure is fitted with a hard cast-iron liner The valves are all worked from the ordinary, independently adjustable link motion, all joints having liberal wearing surfaces, and the position of the links is controlled by a combined steam and hydraulic reverse gear, and also a worm and screw hand reverse gear. The crank shaft is of the built-up type, 13 inches in diameter, and made in three interchangeable parts, with steel crank pins 12 1/2 inches diameter, 14 inches long. Each crank is provided with a counterbalance of sufficient weight to balance the pin and its hubs.

The New Steamer Cape Ann.

This elegant screw steamer was built by Neafie & Levy, Philadelphia, Pa., for the Boston and Gloucester Steamboat Company, of Boston, to ply between the latter city and