China's first seismograph
Seismograph is an instrument for recording earthquakes. It was invented by scientist Zhang Heng in 132 ad. The seismograph is made of copper. It looks like a big wine jar. There is a pillar in the middle. The pillar is next to eight mechanisms. The eight mechanisms are connected with eight dragons outside. Eight heads face eight directions. There is a copper ball in the dragon's mouth, and there is a toad with open mouth squatting under each tap. If there is an earthquake somewhere, the pillar in the middle will fall in that direction, touch the mechanism, and the dragon's mouth in that direction will open, and the copper ball will fall into the clam's mouth with a bang.
The seismograph invented by Zhang Heng is the first seismograph in the world to record earthquakes. In 1880, more than 1700 years later, such instruments appeared in Europe. Related content: the world's earliest seismograph - seismograph