As found in the Encyclopedia Britannica, 1999 "Sometime in the 12th century, mariners in China and Europe made the discovery, apparently independently, that a piece of lodestone, a naturally occurring magnetic ore, when floated on a stick in water, tends to align itself so as to point in the direction of the polestar. This discovery was presumably quickly followed by a second, that an iron or steel needle touched by a lodestone for long enough also tends to align itself in a north-south direction." and further that the "Chinese were using the magnetic compass around AD 1100, western Europeans by 1187, Arabs by 1220, and Scandinavians by 1300." This apparently is not a thorough investigation into the origins of the compass, but rather a single observation perhaps from the English scholar Alexander Neckam, who wrote of sailors using a magnetic compass to assist navigation in 1190, De Utensilibus (On Instruments).
Some speculate that in 101 BCE Chinese ships reached the east coast of India for the first time with help from the navigational compass pioneered by the Chinese. They had discovered the orientating effect of magnetite, or lodestone as early as the 4th century BCE.
The figure to the right shows a working model of the first instrument known to be a compass. The spoon or ladle is of
magnetic lodestone, and the plate is of bronze (non conducting metal). The circular center represents Heaven, and the square plate represents Earth. The handle of the spoon representing the Great Bear, points south.The plate bears Chinese characters which denote the eight main directions of north, northeast, east, southeast, south, southwest, west, northwest, and symbols from the I Ching oracle books which were correlated with directions. Separately marked are the finer gradations of twenty-four compass points, and along the outermost edge are the twenty-eight lunar character representations. Rather than navigation, these simple direction pointers were likely used for geomancy or Fung Shui, the technique of aligning buildings according to forces of nature.
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| Float Comass |
The bowl of water with edge markings (to the left) shows a simple mariner's compass, with a floating magnetized needle pointing north and south.By the time of the T'ang dynasty (7-8th century CE) , Chinese scholars had devised a way to magnetize iron needles, by rubbing them with magnetite, and then suspending them in water (early 11th century). They also had observed that needles cooled from red heat and held in the north-south orientation (the earth's axis) would become magnetic. These more refined needle compasses could then be floated in water (wet compass), placed upon a pointed shaft (dry compass) or suspended from a silk thread. Consequently, they were much more useful for navigation purposes since they were now much more portable (and smaller).
A further refinement in the box compass (to the right) is from about 1200 CE, and is much more suitable for navigation. It retains markings of the heaven's plate around its circumference, in a simplified form. Compass markings generally had an inner circle with the eight trigrams and an outer circle with 24 directions based on azimuth points.
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| Box Compass |
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Reposted From Computer Smiths
By Hendrick Simoes
Lt. j.g. Jeffrey Fasoli, gunnery officer aboard the guided-missile destroyer USS Mason, demonstrates how to operate an M4 carbine rifle to Chinese sailors aboard the Chinese destroyer Harbin prior to a combined small-arms exercise in the Gulf of Aden on Saturday, Aug. 24, 2013. Rob Aylward/ Courtesy of the U.S. Navy
MANAMA, Bahrain — In what could potentially be a small-scale rehearsal for the large scale RIMPAC 2014 exercise, U.S. and Chinese naval forces conducted a joint weekend counter-piracy exercise in the Gulf of Aden.
During the two-day exercise, the guided-missile destroyer USS Mason and the Chinese destroyer Harbin conducted a series of events that included members of both navies taking part in onboard search-and-seizure drills, live-fire proficiency and aviation operations, the U.S. Navy 5th Fleet said.
One of the exercises involved a combined U.S. and Chinese team boarding a Chinese oiler that was role-playing as a pirated vessel. The scenario included hostages and a mock medical emergency.
The joint exercise comes in the wake of last week’s meeting at the Pentagon between Gen. Chang Wanquan, Chinese minister of national defense, and Defense Secretary Chuck Hagel, where both spoke on the importance of building a military-to-military relationship between the two nations that are often politically at odds. At the meeting, both agreed to enhance cooperation in humanitarian assistance and disaster relief, counterterrorism, anti-piracy and peacekeeping.
China is expected to participate in the U.S.-led RIMPAC 2014 , the largest international maritime exercise that takes place biennially in the Pacific. The first bilateral counter-piracy exercise conducted between the U.S. and Chinese navies occurred near the Horn of Africa with USS Winston S. Churchill and the Chinese frigate Yi Yang, in September 2012, according to the U.S. Navy.
U.S. officials say piracy off the Horn of Africa remains a threat despite “significant progress” stemming from a 2009 United Nations Security Council resolution that joined 80 countries in the effort to combat piracy in the area. Since 2011 there has been a 90 percent reduction in the number of hostage-takings by pirates, and the last successful pirate attack on a merchant vessel occurred in May 2012, according to the State Department.
Reposted From Stars and Stripes
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