,compass,The compass was in the earths magnetic field using magnets made the north-south refers to polarity(对立) a point to instrument.,What is compass?,compass,The warring states period,The Song dynasty,The Ming dynasty,Main Timeline,Nowadays,polarity SiNa,Early in the warring states period, using magnets to invent the guidebook instrument - polarity SiNa.,guide fish,Through long-term practice and trial and error, northern people discovered the artificially(人为地) magnetization method, and thereby made guide fish and a compass.,Zheng Hes expeditions,Especially during the Ming Dynasty, Zheng He made expeditions to South-east Asia for seven times, which contributes to the extension and development of seafaring and foreign trade in the world.,Simple compass,Marx had put a compass and printing, the invention of gunpowder is called “is bourgeois（资产阶级） development necessary premise.,Complex compass,NowGPShasalsobeenshowntobeanimportantciviliancommunitiesofinterest,andincreasinglywiderangeofapplication.,function,Direction,Feng shui,Influence,sail,culture,capitalism,Our country is the first state of polarity of the magnet refers to find.,The invention of the compass to the world of the Chinese nation, is a great contributions to civilization.,