The first compass
An early form of the compass was invented in China in the 11th century. The familiar mariner's compass was invented in Europe around 1300, from whence later originated the liquid compass and the gyrocompass.
2007-12-13 17:05:41
·
answer #1
·
answered by An ESL Learner 7
·
1⤊
0⤋
China
Due to disagreement as to when the compass was invented, it may be appropriate to list some noteworthy Chinese literary references offered as possible evidence for its antiquity, in chronological order:
A Han Dynasty (206 BC – 220 AD) ladle-and-basin lodestone south-pointing compass.
A Han Dynasty (206 BC – 220 AD) ladle-and-basin lodestone south-pointing compass.
* The earliest Chinese literature reference to magnetism lies in a 4th century BC book called Book of the Devil Valley Master (鬼谷å): "The lodestone makes iron come or it attracts it."
* The first mention of the magnetic attraction of a needle is to be found in a Chinese work composed between 20 and 100 AD (Lun-heng): "A lodestone attracts a needle." In 1948, the scholar Wang Tchen-touo tentatively constructed a 'compass' in the form of south-indicating spoon on the basis of this text. However, it should be noted that "there is no explicit mention of a magnet in the Louen-heng" and that "beforehand it needs to assume some hypotheses to arrive at such a conclusion".
* The earliest reference to a specific magnetic direction finder device is recorded in a Song Dynasty book dated to 1040-44. Here we find a description of an iron "south-pointing fish" floating in a bowl of water, aligning itself to the south. The device is recommended as a means of orientation "in the obscurity of the night." As Li Shu-hua pointed out in 1954, there was no mention of a use for navigation, nor how the fish was magnetized.[6] However, in Needham's publication Science and Civilization in China: Volume 4, Part 1 in 1962, he proved otherwise, as Wang Chenduo had pointed out. The Wujing Zongyao (æ¦ç»æ»è¦, "Collection of the Most Important Military Techniques") of 1044 stated: "When troops encountered gloomy weather or dark nights, and the directions of space could not be distinguished...they made use of the [mechanical] south-pointing carriage, or the south-pointing fish.This was achieved by heating of metal (especially if steel), known today as thermo-remanence, and would have been capable of producing a weak state of magnetization.
* The first incontestable reference to a magnetized needle in Chinese literature appears as early as 1086 AD.The Dream Pool Essays, written by the Song Dynasty polymath scientist Shen Kuo, contained a detailed description of how geomancers magnetized a needle by rubbing its tip with lodestone, and hung the magnetic needle with one single strain of silk with a bit of wax attached to the center of the needle. Shen Kuo pointed out that a needle prepared this way sometimes pointed south, sometimes north.
* The earliest recorded actual use of a magnetized needle for navigational purposes then is to be found in Zhu Yu's book Pingzhou Table Talks (èæ´²å¯è«; Pingzhou Ketan) of AD 1119 (written from 1111 to 1117 AD): The navigator knows the geography, he watches the stars at night, watches the sun at day; when it is dark and cloudy, he watches the compass. This of course would have been aided by Shen Kuo's discovery (while working as the court's head astronomer) of the concept of true north: magnetic declination towards the magnetic north pole away from the polestar.
Thus, the first clear instance of a magnetic direction finder, a compass, appeared ca. 1044. However, it should be pointed out that the compass remained in use by the Chinese in the form of a magnetic needle floating in a bowl of water.
2007-12-15 10:45:05
·
answer #4
·
answered by Jeremiah Zacarias 2
·
2⤊
0⤋