China History_of_the_compass

model of han dynasty (206 bc–220 ad) south-indicating ladle or sinan. theorized south-pointing spoons of han dynasty magnetized lodestones.

there disagreement when compass invented. these noteworthy chinese literary references in evidence antiquity:

the magnetic compass first invented device divination chinese han dynasty (since 206 bc). compass used in song dynasty china military navigational orienteering 1040–44, , used maritime navigation 1111 1117.
the earliest chinese literature reference magnetism lies in 4th century bc writings of wang xu (鬼谷子): lodestone attracts iron. book notes people of state of zheng knew position means of south-pointer ; authors suggest refers use of compass.
the first mention of spoon, speculated lodestone, observed pointing in cardinal direction chinese work composed between 70 , 80 ad (lunheng), records when south pointing spoon thrown upon ground, comes rest pointing @ south. within text, author wang chong describes spoon phenomenon has observed. although passage not explicitly mention magnetism, according chen-cheng yih, device described wang chong has been considered earliest form of magnetic compass.
the first clear account of magnetic declination occurs in kuan shih ti li chih meng ( mr. kuan s geomantic instructor ), dating 880. text, chiu thien hsuan nu chhing nang hai chio ching ( blue bag sea angle manual ) around same period, has implicit description of magnetic declination. has been argued knowledge of declination requires use of compass.
a reference magnetized needle mysterious needle appears in 923–926 in chung hua ku chin chu text written ma kao. same passage attributed 4th-century ad writer tshui pao, although postulated former text more authentic. shape of needle compared of tadpole, , may indicate transition between lodestone spoons , iron needles.
the earliest reference specific magnetic direction finder device land navigation recorded in song dynasty book dated 1040–44. there description of iron south-pointing fish floating in bowl of water, aligning south. device recommended means of orientation in obscurity of night. wujing zongyao (武經總要, collection of important military techniques ) stated: when troops encountered gloomy weather or dark nights, , directions of space not distinguished...they made use of [mechanical] south-pointing carriage, or south-pointing fish. achieved heating of metal (especially if steel), known today thermoremanence, , have been capable of producing weak state of magnetization. while chinese achieved magnetic remanence , induction time, in both europe , asia phenomenon attributed supernatural , occult, until 1600 when william gilbert published de magnete.
the first incontestable reference magnetized needle in chinese literature appears in 1088. dream pool essays, written song dynasty polymath scientist shen kuo, contained detailed description of how geomancers magnetized needle rubbing tip lodestone, , hung magnetic needle 1 single strain of silk bit of wax attached center of needle. shen kuo pointed out needle prepared way pointed south, north.
the earliest explicit recorded use of magnetic compass maritime navigation found in zhu yu s book pingchow table talks (萍洲可談; pingzhou ketan) , dates 1111 1117: ship s pilots acquainted configuration of coasts; @ night steer stars , , in daytime sun. in dark weather @ south pointing needle.


diagram of ming dynasty mariner s compass

thus, use of magnetic compass military land navigation occurred sometime before 1044, incontestable evidence use of compass maritime navigational device did not appear until 1117.

the typical chinese navigational compass in form of magnetic needle floating in bowl of water. according needham, chinese in song dynasty , continuing yuan dynasty did make use of dry compass, although type never became used in china wet compass. evidence of found in shilin guangji ( guide through forest of affairs ), published in 1325 chen yuanjing, although compilation had taken place between 1100 , 1250. dry compass in china dry suspension compass, wooden frame crafted in shape of turtle hung upside down board, lodestone sealed in wax, , if rotated, needle @ tail point in northern cardinal direction. although european compass-card in box frame , dry pivot needle adopted in china after use taken japanese pirates in 16th century (who had in turn learned of europeans), chinese design of suspended dry compass persisted in use 18th century. however, according kreutz there single chinese reference dry-mounted needle (built pivoted wooden tortoise) dated between 1150 , 1250, , claims there no clear indication chinese mariners ever used floating needle in bowl until 16th century.

the first recorded use of 48 position mariner s compass on sea navigation noted in customs of cambodia yuan dynasty diplomat zhou daguan, described 1296 voyage wenzhou angkor thom in detail; when ship set sail wenzhou, mariner took needle direction of “ding wei” position, equivalent 22.5 degree sw. after arrived @ baria, mariner took kun shen needle , or 52.5 degree sw. zheng s navigation map, known mao kun map , contains large amount of detail needle records of zheng s expeditions.