or a displacement of about 700 cubic feet, corresponding to a maximum draught of 3.7 feet. The mean speed is 4 knots, or 4½ miles per hour, a great velocity being unnecessary, owing to the small distance to cross in a port often obstructed by the general movement of vessels taking place therein.
The engine is from 16 to 18 horse-power. Its frame is inclined perpendicularly to the direction of the screw-shaft, the extremity of which is supported near the screw by a strengthened cross-stay serving as a pillow-block. The cylinder is 8 inches in diameter, and the piston has a stroke of 6 inches, causing the screw (which is 3¼ feet diameter) to make 200 revolutions per minute. The screw, although it has a wide surface of thrust, gives, nevertheless, a recoil of about 30 per cent., because of its location between the hulls and its oblique action on the shaft.
The steam is furnished by a tubular boiler having an internal fireplace and a heating surface of sixteen square meters, the draught being effected by the exhaust of the engine. This boiler, which is tested up to 14 pounds, is fed by a steam pump, or by a pump actuated by the engine. The feed pumps take water successively from one or the other of the reservoirs in the hulls. The reservoirs are filled in the morning, and their level is ascertained by two small and ingenious Decondun indicators, the dials of which are placed against the walls of the engine-room.
Taken altogether, these little boats are well arranged and quite handsome; and, since they were put into service in June, 1880, they have proved a great convenience to the hard-working and active population for which they were built.
OPENING OF A NEW ENGLISH DOCK.
In July last, Admiral the Duke of Edinburgh, with the Naval Reserve Squadron under his command, arrived in the Firth of Forth and anchored in Leith Roads. His Royal Highness performed the ceremony of opening the new dock at Leith, which has been named after him. The "Edinburgh" Dock at Leith, which was commenced in 1874, consists of a center basin 500 ft. long and 650 ft. wide, and two basins 1,000 ft. long and 200 ft. wide, separated by a jetty having a width of 250 ft. The total amount of masonry in the wet docks is 100,000 cubic yards. The north and south quays are each 1,500 ft. long, and the two sides of the jetty 1,000 ft. long each, having a total quayage in connection with the dock of 6,775 ft. The walls are 15 ft. thick at the base, narrowing in two tiers to 8 ft. The new dock will cost altogether about £300,000. Leith now possesses five docks and a total quayage of three miles 808 yards, 1,234 yards of which is the old portion. These works have been constructed, at a cost of nearly one million sterling, by the Leith Dock Commissioners, whose chairman, Mr. James Currie, presented an address to the Duke of Edinburgh, on board the flag-ship H.M.S. Hercules, giving an account of their affairs. The other docks at Leith are named the "Old Dock," the "Queen's Dock," the "Victoria," the "Albert," and the "Prince of Wales Dock." The opening ceremony was arranged to consist of the steamer Berlin, with his Royal Highness and the Dock Commissioners on board, accompanied by Sir Donald Currie, M.P., and other gentlemen, passing through the entrance from the Albert Dock to the new dock, across which a blue ribbon had been stretched. At the moment when the ribbon snapped asunder, under the bow of the Berlin, the Duke of Edinburgh, stepping forward on the upper deck of the steamer, said, "I have now the gratification of declaring this dock open, and calling it the Edinburgh Dock." On this announcement being made, a signal was conveyed to a battery of guns, posted on the sea wall of the new dock, from which a party of the Royal Artillery fired a Royal salute. The steamer, having gone round the new dock, was brought up at the quay at the west. His Royal Highness the Duke of Edinburgh, with Prince Henry of Prussia, the officers of the fleet, and the Commissioners, disembarked and proceeded to the saloon in the new dock, where luncheon in honor of the occasion was given by the Leith Dock Commissioners.--Illustrated London News, Aug. 6.
OPENING OF A NEW ENGLISH DOCK.