地球内部过程 Earthquake Epicenter震中 and Focus震源:(中国人发明的地震仪) The scientific study of earthquakes began with the chinese as early as 132 A.D. Chang Heng a chinese astronomer and mathematician, invented an earthquake weathercock /xlt, an instrument consisting of an array of loosely held balls in the mouths of eight dragons facing at angles of 45 from one another. An internal mechanism, activated by even a slight tremor, opened the mouth of a dragon releasing a ball which fell into the open mouth of a toad#s s below, sounding an alarm The direction of the earthquake could be determined by the orientation of the empty-mouthed dragon 环境迪顶学 minoucntalocelogu ,率地球内部过程 Earthquake Epicenter震中 and Focus震源: (中国人发明的地震仪） The scientific study of earthquakes began with the Chinese as early as 132 A.D. Chang Heng, a Chinese astronomer and mathematician, invented an earthquake weathercock风标, an instrument consisting of an array of loosely held balls in the mouths of eight dragons facing at angles of 45° from one another. An internal mechanism, activated by even a slight tremor, opened the mouth of a dragon, releasing a ball which fell into the open mouth of a toad蟾蜍below, sounding an alarm. The direction of the earthquake could be determined by the orientation of the empty-mouthed dragon