Magnetic navigational compass
Compás magnético de navegación
- Date
- c. 1100 · confidence high
- Place
- Guangzhou / Kaifeng, Song China
- Credited to
- Shen Kuo (description, 1088); Guangzhou sailors (use, 1119)
- People
- 👤 Shen Kuo1031–1095
- Field
- Movement
⚠️ Disputed: the sources disagree.
What it is
A magnetised needle floating on water that points south, described by Shen Kuo and used on board ship according to Zhu Yu (1119). The first orientation instrument independent of the sky.
It is debated whether Europe received it from China via the Islamic world or rediscovered it independently; its near-simultaneous appearance (1190), a century after Chinese use began, supports transmission.
What it led to
- navigation under overcast skies and reliable oceanic routes
- transmission to Islamic and European sailors (Alexander Neckam, 1190)
- bearing-based cartography and portolan charts
Built on
- Thermoremanent magnetisation (south-pointing fish)1044
- Magnetic declination described by Shen Kuo1088
- Han magnetic divination spoon (sinan)
- lodestone (magnetite)
Made possible
- Portolan chartc. 1290
- Dry compass with wind rosec. 1300
- Caravelc. 1440
- Compensating compass deviation in iron ships (Airy)1839
- Liquid-filled marine compass1862
- Dry compass with wind rose
- Portolan chart