地动仪 dìdòngyí seismograph Definitions Defs Origin Strokes Stroke Words Sentences Sents 候风地动仪 hòufēngdìdòngyí Houfeng Didong Yi The world's first seismograph, invented by the astronomer [[张衡|張衡|zhang1 heng2]] in 132 AD during the Eastern Han dynasty.
