Compass | Navigator’s Equipment

 Compass | Navigator’s Equipment

 

Like numerous inventions used extensively in the West, the compass was first developed in China, in the 1st century B.C. A ladle- shaped lodestone could be used to determine north, and south- pointing compasses were made in such a shape from attraction. The heavier or spoon end of the ladle would swing to the north on a position face, while the handle or pointer of the ladle would swing to the south. As early as A.D. 1086 the Chinese were manufacturing magnetized blade or iron needles that would be mounted on pivots or floated in water to reduce disunion and to indicate north – south direction. A Chinese compass with a pivot was described in the Sung dynasty (1127 – 1279), in the shape of a turtle. The Chinese first used compasses not as an aid to travel but as a device to determine directions when aligning the construction of structures and roads. 

Yet the Chinese did use the compass for navigation well before the Europeans. Records indicate that Chinese aviators used compasses as early as the 12th century to determine direction when clouds obscured the Sun or the stars. The fact that a compass varies from true north because the magnetic North Pole is slightly displaced from the true North Pole (a difference called declination) was known to the Chinese in the 1200s and 1300s, and they produced maps representing the degrees of declination in that period. European shipmen began to fete declination in the 15th century. 

    The first European jotting about the compass was Alexander Neckam (1157 – 1217). In 1187 he described both floating and swirled compasses. By the 1300s, European mariners used compasses mounted on a “ rose ” showing the directions; a fastened magnetic needle on the rose would allow the whole card with the directions to turn, giving an easy reading for the Sailor.