large craft in which persons and goods may be conveyed on water. In the U.S. Navy the term boat refers to any vessel that is small enough to be hoisted aboard a ship, and ship is used for any larger vessel; all submarines, no matter what size, are designated as boats, and ship-sized vessels are often referred to colloquially as boats (e.g. steamboats).

Seagoing vessels large enough to be called ships were used in ancient times by the Egyptians, Cretans, Greeks, Phoenicians, Romans, and Chinese. Ancient ships were propelled by oars or by sails or by both. They were of different types for different functions. Heavy, slow ships with round bottoms were used to transport grain, while slim-keeled ships such as the trireme were used for warfare (see galley ). In the Middle Ages Viking ships, propelled by both oars and sails, carried Leif Eriksson to America; their structure is well known from such evidences as the Gokstad ship (unearthed in 1880), which is 80 ft (24.4 m) long, 16 ft 6 in. (5 m) wide, and 6 ft 10 in. (2.1 m) deep.

The introduction of the mariner's compass, the sternpost rudder, and the lateen sail made possible the transoceanic voyages of the Portuguese who rounded Africa and of Columbus and other explorers of the New World, giving new impetus to the building and navigation of ships. Many sturdy and refined types of wooden sailing vessels up to three hundred feet in length were developed. Men-of-war included the ship of the line, the frigate, and the corvette. Differing especially in such details as number and position of masts, with sails either square-rigged or fore-and-aft, ships were differentiated into such types as brig, clipper, and schooner. Building wooden ships became an important industry, especially in Britain and the United States.

The success of Fulton's Clermont on the Hudson River (1807) prepared the way for the superseding of sailing ships by steamships (see steamship ), and later in the 19th cent. steel began to replace wood as material for shipbuilding. Steel ships can be made much larger than wooden ships. The steam engine was followed by the steam turbine, which actuated the propeller directly or through gear mechanisms. Both methods of power production underwent many improvements through the years before the diesel engine came (1902–3) into maritime use. In some ships, diesel engines are now used to generate electricity, which is used to power propeller motors. In the 1950s nuclear power was introduced in military vessels and icebreakers; modern nuclear submarines can travel submerged for months at a time (see nuclear energy ).

Modern freight ships are equipped with powerful machines for handling cargo; and, although jet transportation led to the demise of the great ocean liners, cruise ships continue to be built, providing the luxuries of the finest hotels. The pivotal vessels of modern warfare are the aircraft carrier and the submarine ; other warships important in recent times include the battleship, cruiser, and destroyer.

See H. B. Mason, Encyclopedia of Ships and Shipping (1977); G. Blackburn, The Illustrated Encyclopedia of Ships, Boats, and Vessels (1982); K. J. Rawson and E. C. Tupper, Basic Ship Theory (1983); A. Kludas, Great Passenger Ships of the World (5 vol., 1986–87); Jane's Fighting Ships (pub. annually since 1897).

The Columbia Encyclopedia, Sixth Edition Copyright© 2004, Columbia University Press. Licensed from Lernout & Hauspie Speech Products N.V. All rights reserved.

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