Click the link for more information. could be used to find latitude and a log line and half-minute glass could help keep track of distance traveled but the problem of finding the longitude remained unsolved until the invention of the chronometer. It is sometimes confused with the sextant, a similar instrument based on a scale of 60°. In technology, angle-measuring device based on a scale of 90°. by the Scottish mathematician John Napier all helped advance navigation.īy the middle of the 18th cent. Click the link for more information.'s work in improving charts at the end of the 16th cent., the works of the Spanish scientist Martín Cortés during the same period, the determining of the earth's circumference, and the introduction of logarithms at the beginning of the 17th cent. From 1537 to 1540 he surveyed and mapped Flanders.
He studied in Louvain, where he had a geographical establishment (1534). , 1512–94, Flemish geographer, mathematician, and cartographer. Vasco da Gama on his first voyage around the Cape of Good Hope in 1497 used an astrolabe. The navigating equipment carried by Columbus probably was simply a compass, a cross-staff, and a table of the sun's declination. Although its origin is ancient and obscure, its invention is frequently ascribed either to Hipparchus or to Apollonius of Perga. , instrument probably used originally for measuring the altitudes of heavenly bodies and for determining their positions and movements. Another device used for finding latitude was the astrolabe astrolabe The altitude could then be read on a scale marked on the staff. To measure the altitude of a heavenly body, the instrument was sighted in that direction, and the cross was moved forward or back until the heavenly body appeared through the upper hole and the horizon through the lower. (66-cm) cross a small hole was bored, and at the end of the staff a sight was fixed. It consisted of two pieces of wood, the cross at right angles to, and sliding on, the staff. The cross-staff was used to find latitude early in the 15th cent. With the development of shipbuilding and the increase in knowledge of astronomy, there was increased use of instruments. Click the link for more information., who built an observatory and formulated tables of the declinations of the sun collected a great amount of nautical information, which he placed in practical form made charts and sponsored expeditions that led to numerous discoveries. Because he fought with extraordinary valor in the Portuguese conquest of Ceuta (1415), he was created duke of Viseu by his father, John I, king of Portugal. there was progress by the Portuguese under the leadership of Prince Henry the Navigator Henry the Navigator,ġ394–1460, prince of Portugal, patron of exploration. Frequently called a pair of compasses, it consists of two metal legs with one end of each attached to a pivot to form a V-shaped device. A tremendous advance in navigation had taken place with the introduction of the compass compass.ġ In mathematics, an instrument for making circles and measuring distances. During this period the study of bodies of water, or hydrography, was given much attention, and harbors and the outlets of rivers were surveyed and buoyed. In England, Queen Elizabeth I did much to establish navigation laws, giving additional powers to Trinity House, a guild that had been created in 1514 for the piloting of ships and the regulation of British navigation. The Pacific islanders navigated from island to island across the open ocean using observations of guide stars and the moon, the winds, waves, and currents, and birds, knowledge of which was passed from generation to generation the Polynesians especially traversed enormous stretches of the Pacific. Click the link for more information. to aid their voyages.
The Vikings and Norsemen, who crossed the Atlantic to Iceland, Greenland, and Newfoundland, are reputed to have used a sunstone sunstone.ġ Crystal mineral thought by some to have been used by the Vikings as an aid to navigation, especially in conditions of low visibility due to clouds or fog when the position of the sun was uncertain. They built large ships and, traveling out of sight of land by day and by night, probably circumnavigated Africa. The Phoenicians were among the most daring of the ancient navigators. In ancient times, mariners navigated by the guidance of the sun and stars and landmarks along the coast. Navigation, science and technology of finding the position and directing the course of vessels and aircraft.
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