German geophysicist Weixie Er (E.wiechert, 1861-1928) has designed and manufactured a pendulum swing mechanical seismograph, has been widely used in the world's seismic stations. This seismograph Taiwan Meteorological Agency after the war, was presented mainland scientists. This seismograph weighs seventeen tons, present, except Goettingen, Germany, the Nanjing baseline seismic probably unique in this seismograph is still running today. It is the world's largest and most important remaining seismograph. It consists of two parts: all observations horizontal direction, perpendicular to the observation direction. Wei Xieer seismograph is purely mechanical seismographs recorded seismic waves inverted pendulum. By mechanical cylinder to the recorder (recording fume), they recorded seismic waveform with a period of 1.4 seconds. Two seismometers appearance cylindrical middle have a huge "pendulum." The left side of a slender seismograph "hook", the hook is the "stylus", with spinning reels and down, "hook" in the black paper leaving a thin white line road. Why black paper will leave a character asks line? "This was originally a white rolls, is after a smoky kerosene lamp after special treatment to become black." 维歇尔 seismographs have a balance of the pendulum, as long as the ground occurred a little "shake" The pendulum will exercise the power it produces will also spread "stylus", thereby complete record of the entire seismic waves.