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Although there is tantalizing evidence that the Mesoamerican Olmecs were familiar with magnetism and even developed a compass in the 2nd millennium BC,[1] at present the honor of inventing the compass belongs to the Chinese. The earliest recorded use of lodestone as a direction finder was in a 4th century BC Chinese book: Book of the Devil Valley Master (鬼谷子). The compass is considered one of the Four Great Inventions of Ancient China.

Dream Pool Essay written by Song Dynasty scholar Shen Kua in AD 1086 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 Kua pointed out that a needle prepared this way sometimes pointed south, sometimes north.



The earliest recorded use of a compass in navigation lies in Zhu Yu's book Pingzhou Ke Tan (Pingzhou Table Talks) of AD 1117.

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

A pilot's compass handbook titled Shun Feng Xiang Song (Fair Winds for Escort) in the Oxford Bodleian Library contains great details about the use of compass in navigation.

Navigational mariner's compass
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Navigational mariner's compass

After this point there is much debate on what happened to the compass. Theories include its travel to the Middle East via the Silk Road, and then to Europe, direct transfer of the compass from China then Europe and then later from Europe to the Middle East, as well as independent creation of the compass in Europe and then its transfer thereafter to the Middle East. The latter 2 are supported by evidence of the Arabic word for "Compass" (al-konbas) possibly being a derivation of the old Italian word for compass. Other evidence for this includes the earlier mentioning of the compass in European works rather than Arabic. The first European mention of the directional compass occurs in Alexander Neckam's De naturis rerum (On the Natures of Things), probably written in Paris in 1190. As for the Arab world, Yemeni Sultan al-Ashraf appears to be the earliest confimed mention of the compass in 1290, though some authors assert an earlier recording, as early as 1242 for Arabic, and 1231 for Persian.

In China it seems that the convention was that the compass spoon (they used a spoon instead of a needle) pointed south. Since the European convention has always been the opposite it has been suggested that independent invention may be more likely than cultural diffusion from China in this case.

Prior to the introduction of the compass, direction at sea was primarily determined by the position of celestial bodies. Navigation was supplemented in some places by the use of soundings. Difficulties arose where the sea was too deep for soundings and conditions were continually overcast or foggy. Thus the compass was not of the same utility everywhere. For example, the Arabs could generally rely on clear skies in navigating the Persian Gulf and the Indian Ocean (as well as the predictable nature of the monsoons). This may explain in part their relatively late adoption of the compass. Mariners in the relatively shallow Baltic made extensive use of soundings.

In the Mediterranean, however, the practice from ancient times had been to curtail sea travel between October and April, due in part to the lack of dependable clear skies during the Mediterranean winter (and much of the sea is too deep for soundings). With improvements in dead reckoning methods, and the development of better charts, this changed during the second half of the 13th century. By around 1290 the sailing season could start in late January or February, and end in December. The additional few months were of considerable economic importance; it enabled Venetian convoys, for instance, to make two round trips a year to the eastern Mediterranean, instead of one.

Around the time Europeans learned of the compass, traffic between the Mediterranean and northern Europe increased, and one factor may be that the compass made traversal of the Bay of Biscay safer and easier.


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