Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
August 06, 2010 Compass běi 指南针 zhǐnán zhēn dōngběi xīběi dōng xī dōngnán xīnán nán Click to see how to write direction characters! August 06, 2010 The Invention of the Compass 1. The magnetic compass is an old Chinese invention , probably first made in China during the Qin dynasty (221-206 B.C.). Chinese fortune tellers used lodestones (a mineral composed of an iron oxide which aligns itself in a north-south direction) to construct their fortune telling boards. 2. Eventually someone noticed that the lodestones were better at pointing out real directions, leading to the first compasses. 3. They designed the compass on a square slab which had markings for the cardinal points and the constellations. The pointing needle was a lodestone spoon-shaped device, with a handle that would always point south. 4. Magnetized needles used as direction pointers instead of the spoon-shaped lodestones appeared in the 8th century AD, again in China, and between 850 and 1050 they seem to have become common as navigational devices on ships. 指南针 zhǐ nán zhēn August 06, 2010 NE NW E W SE SW S N W S E August 06, 2010 The magnetic compass is an old Chinese invention, probably first made in China during the Qin dynasty (221-206 B.C.). Chinese fortune tellers usedlodestones (a mineral composed of an iron oxide which aligns itself in a northsouth direction) to construct their fortune telling boards. The first person recorded to have used the compass as a navigational aid was Zheng He (1371-1435), from the Yunnan province in China, who made seven ocean voyages between 1405 and 1433. When Chinese first invented the compass, the needle was a magnetized ladle or spoon that symbolized many things, including the timekeeping Ladle in the skies (successively Doumou, Nandou , and Beidou). The spoon pointed to geographic south, which is why its name is "the south-pointing spoon." Chinese compasses have always pointed to the magnetic north pole, which we call the geographic South Pole. August 06, 2010 Si Nan is China's earliest south-north directionpointing device invented in the Spring and Autumn and Warring States Period. The word "Si" means "pointing to" and "Nan" means "the South". As early as more than 2,000 years ago, the Chinese discovered that a type of mountain stone was magnetic and they called it "magnetic stone". The stone was polished and chiseled into the shape of a dipper, which was placed on a mirror-smooth bronze board carved with patterns indicating directions. When the magnetic dipper on the board stops turning, the handle of the dipper will point to the exact south, with the other end pointing to the exact north. This is Si Nan, the world's earliest direction-pointing device invented by the Chinese. August 06, 2010 "The south-pointing fish" was recorded in the documents of the Northern Song Dynasty. Such direction-pointing device is a thin steel plate cut into the shape of a fish magnetized in the geomagnetic field. The tail of the fish is magnetized in the geological direction of the North Pole, thus the tail has the south magnetic pole and the head of the fish has the north magnetic pole. When put into the water, the floating fish has its head pointing to the south. August 06, 2010 August 06, 2010