Additional Information In lieu of an abstract, here is a brief excerpt of the content: Many of the texts that formed this interpretive tradition were read either in the original or in translation by European settlers in the Americas. One might think that Americans supporting political independence from their respective European metropolises would discard the figure of Columbus as a relic of the Old World, as a symbol of the monarchical political system they sought to end in their land. But instead they adopted Columbus as a symbol of their newly independent nations.
Latitude Roughly, the latitude of a place on Earth is its angular distance north or south of the equator. The height of Polaris in degrees above the horizon is the latitude of the observer, within a degree or so.
Longitude Similar to latitude, the longitude of a place on Earth is the angular distance east or west of the prime meridian or Greenwich meridian. For most of history, mariners struggled to determine longitude.
Longitude can be calculated if the precise time of a sighting is known. Lacking that, one can use a sextant to take a lunar distance also called the lunar observation, or "lunar" for short that, with a nautical almanaccan be used to calculate the time at zero longitude see Greenwich Mean Time.
A mariner with a chronometer could check its reading using a lunar determination of Greenwich time. Rhumb Line In navigation, a rhumb line or loxodrome is a line crossing all meridians of longitude at the same angle, i. That is, upon taking an initial bearing, one proceeds along the same bearing, without changing the direction as measured relative to true or magnetic north.
Modern technique[ edit ] Most modern navigation relies primarily on positions determined electronically by receivers collecting information from satellites. Most other modern techniques rely on crossing lines of position or LOP.
If the navigator draws two lines of position, and they intersect he must be at that position. There are some methods seldom used today such as "dipping a light" to calculate the geographic range from observer to lighthouse Methods of navigation have changed through history.
Modern navigation methods Description Application Dead reckoning or DR, in which one advances a prior position using the ship's course and speed. The new position is called a DR position.
It is generally accepted that only course and speed determine the DR position. Correcting the DR position for leewaycurrent effects, and steering error result in an estimated position or EP. An inertial navigator develops an extremely accurate EP. Pilotage involves navigating in restricted waters with frequent determination of position relative to geographic and hydrographic features.
Celestial navigation involves reducing celestial measurements to lines of position using tables, spherical trigonometryand almanacs.
Used primarily as a backup to satellite and other electronic systems in the open ocean. Radio navigation uses radio waves to determine position by either radio direction finding systems or hyperbolic systems, such as DeccaOmega and LORAN-C.
Losing ground to GPS.
Radar navigation uses radar to determine the distance from or bearing of objects whose position is known.Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another. The field of navigation includes four general categories: land navigation, marine navigation, aeronautic navigation, and space navigation.
JSTOR is a digital library of academic journals, books, and primary sources. PRIMO, the largest independent national magazine for and about Italian Americans, provides quality journalism on Italian American history, heritage, and achievements. PRIMO discusses topics of importance to Italian Americans with articles on Italian art, language, travel, food and wine.
Piratical Dates of Importance (updated 30 June ). This time line is a work in progress. It incorporates events important to piratical history, but . John II (Portuguese: João II; [ʒuˈɐ̃w̃]; 3 March – 25 October ), called the Perfect Prince (Portuguese: o Príncipe Perfeito), was King of Portugal from until his death in , and also for a brief time in He is known for re-establishing the power of the Portuguese monarchy, reinvigorating the Portuguese economy, and renewing his .
A Short Caucasian Bibliography. viz. a comprehensive, illustrated & regularly updated. BIBLIOGRAPHY OF WORKS. relating to the. wider Caucasus region — Its .