Zhang Heng's seismoscope detected distant earthquakes in 132 AD China

March 23, 2026General

Source: Ancient Inventions Similar to Advanced Modern Technology by Universe Inside You

In 132 CE, Chinese polymath Zhang Heng unveiled a bronze seismometer! 🐉 8 dragon heads held metal balls — seismic waves could trigger one to drop, revealing the quake's direction. Zhang's invention was an impressive feat of ancient engineering, though historical records about its real-world performance remain debated among scholars. 🌍

Key facts

Invented by Chinese polymath Zhang Heng in 132 AD during Han Dynasty
Large bronze vessel with eight dragon heads aligned to cardinal and diagonal directions
Bronze toads positioned beneath each dragon head with open mouths
Metal balls rested in each dragon's mouth
Internal mechanism used suspended pendulum or balanced mass to detect seismic vibrations
When earthquake occurred, corresponding dragon head opened and dropped ball into toad below
Direction of fallen ball indicated earthquake location
Initially met with skepticism from Imperial Court officials
Validated when device detected distant earthquake to the west; messengers confirmed event occurred hundreds of miles away

Sources

The world's first seismometer used a toad to catch an earthquakenewscientist.com

Featuring bronze toads and dragons, a legendary tremor detector was made by polymath Zhang Heng in AD 132 – but did it really work? The evidence is shaky.

Zhang Heng - Wikipediaen.wikipedia.org

To indicate the direction of a distant earthquake, Zhang's device dropped a bronze ball from one of eight tubed projections shaped as dragon heads; the ball ...

Zhang Heng's dragon seismoscope · Creation.comcreation.com

This seismoscope, designed to detect when an earthquake had occurred and from what direction, was invented by Zhang Heng (AD 78–139). He was a ...

Was this story useful?

← All stories