escape, when the piston with the tup falls, striking the object placed on the hammer. The blows may be so regulated as just to crack an egg or to strike with a force of tons. In modern steam-hammers the force of the blow is increased by the pressure of the steam above the piston, and by automatic valve-mechanisms the blows can be repeated with great rapidity. The largest steam-hammer ever built is that built for the Bethlehem Iron-Works in 1891. The piston with tup weighs 125 tons, the cylinder has a diameter of 76 inches, and the length of the stroke is 16½ feet. Such large hammers are no longer used, as the work is done better and cheaper by large hydraulic presses. The Bethlehem steam-hammer has been superseded by a 14,000-ton hydraulic press.
STEAM-HAMMER
Steam′ship, a vessel moved by steam. A half-successful experiment was made by Papin to use steam to propel a boat as early as 1707, but it was not until the perfecting of the steam-engine by Watt that any advance was made in steam-navigation. Early inventors of steamboats were William Henry, 1783, and John Fitch, 1785-96, in the United States and William Symmington and Henry Bell in Great Britain, but the first steam-vessel to make a voyage of any considerable length was the Clermont, made by Robert Fulton in 1807. She was 133 feet long, and made the voyage of 150 miles from New York to Albany in 32 hours. In the same year Col. John Stevens built at New York the Phœnix, which was taken around to Delaware River by sea because Fulton had a monopoly of steam-navigation on the Hudson. This was the first steamboat to make a sea-voyage. The first passenger steamboat in operation in Europe was the Comet on the Clyde in 1812, although a successful boat had been on the Clyde Canal as early as 1802. The first steamship to cross the ocean was the Savannah, a ship of 350 tons, which made the voyage from Savannah, Ga., to Liverpool and thence to St. Petersburg in 1819. Both sails and steam were used. The voyage to Liverpool was made in 25 days. The first vessels to cross the Atlantic using steam the whole distance were the Great Western and the Sirius, which reached New York on the same day, April 23, 1838. Since then the transatlantic steamship-service from New York has been continuous. All the earlier steamships were propelled by wheels at the side or at the ends. The screw-propeller was introduced by Smith and Ericsson about 1840 (see Screw-Propeller), and since then all ocean-steamers and many inland steamers use it. Iron and steel have superseded wood for large ships, and steamships have continued to grow in size, power of engines and speed. The voyage from New York to England is now made in four days and fifteen hours by the fastest ship or in seven days by the slow steamers. The largest and fastest steamers on the ocean to-day are the Deutschland, length 686 feet, displacement 23,000 tons, average speed 23.36 knots per hour, H. P. of engines 35,000; Oceanic, length 704 feet, displacement 28,000 tons, average speed 20.48 knots per hour, H. P. of engines 28,000; Lusitania, 790 feet long, 32,000 tons' displacement and average speed 25.05 knots an hour; and Mauretania, 790 feet long, 32,000 tons' displacement and average speed 24.86 knots an hour.
STEAMSHIP LUSITANIA
Each of the last two steamers has 70,000 horse-power. The White Star Line is building two Atlantic liners of 42,000 tons' burden each and over 900 feet in length. The Mauretania and Lusitania are quadruple-screw turbines and are not merely floating hotels or palaces but cities at sea. The average daily coal-consumption of the
