Navigation
the art or science of navigating or conducting vessels from one port to another, on the ocean, by the best routes. Navigation more especially means the art of directing and measuring the course of ships, and of determining the position of the ship at any moment, and the direction and distance of her destination. There are two methods of determining the position of a ship at sea; the first by means of the reckoning; that is, from a record which is kept of the course sailed and distances made on each course; the second is by means of observations made on the heavenly bodies, and the aid of spherical trigonometry. The first method gives only approximate results; the second admits of great accuracy. The position of the vessel being known at any moment, the direction and distance of any other point may be determined either by the aid of a chart, or by the application of the principles of trigonometry. To the approximate methods of determining a ship's position it is necessary to add frequent checks by astronomical observations.
The principal objects to be attained by astronomical observations are, to ascer tain the latitude, the longitude, and the variation of the needle, for correcting the dead reckoning.
NAVIGATION LAWS. Very little change has been made in the navigation laws of the United States since their adoption in 1792-1793. The main features of these laws may be summed up as follows: No vessel, unless entirely built in this country and wholly owned and officered by Americans, is considered an American vessel having the right to be protected by the American flag. No foreign vessel is permitted to engage in the American coasting trade, the same extending from Atlantic to Pacific ports American vessels are no longer considered as such if even a part-owner (with a few exceptions) resides abroad for a short time. Transfer of an American vessel to foreigners prohibits it from NAVY ever again sailing under the American flag. If an American vessel makes any repairs in a foreign port, duty must be paid on the value of all such repairs on her return to this country. The repairing of foreign vessels in our ports, with foreign materials, is placed under restriction. A tax of six cents per ton of their burden, called a tonnage tax, is imposed on all vessels (except fishing and pleasure vessels) engaged in trade to ports not in North or Central America and a few other specified places, the maximum aggregate tax in any one year not exceeding 30 cents. Foreign vessels pay the same tax, but if one of the officers of an American vessel is a foreigner, it NAVY manded the sea, but their power waned between 870 and 650 B. c., and Carthage, . cc., and Carthage, a Phœnician colony, gradually surpassed the parent state in sea-power. One of the earliest recorded sea-fights was the battle of Salamis, 480 B. c., when the , 480 B. C., when the Greeks under Themistocles defeated the fleet of Xerxes, which marked the turning point in the last Persian invasion. A Carthaginian vessel wrecked on the coast of Italy supplied the Romans with the model for their navy. The first great naval battle of the Romans was fought 260 B. C. off the Lipari Islands when Duilius defeated a superior Carthaginian fleet under Hannibal.
The galley, the warship of the Greeks, BRITISH SUPER-DREADNOUGHT HOOD is forced to pay an additional tax of 50 cents. Materials for the construction of vessels for foreign trade may be imported free of duty, but the duty must be paid if the vessel engages for more than two months a year in the coasting trade.
American vessels may unload at any port of delivery in the customs district, but foreign vessels can only discharge their cargoes at a port of entry, which is a certain designated port in each customs district in the United States. Exceptions are made when they are laden with coal, salt, or similar merchandise in bulk.
NAVIGATORS' ISLANDS. See SAMOAN ISLANDS.