Saed News: In the year 132 AD, a Chinese scientist named Zhang Heng built a device that could detect earthquakes without the need for electricity; even earthquakes occurring hundreds of kilometers away.
According to the History Service of Saed News, in the year 132 AD, a device called “Houfeng Didong Yi” (meaning “Instrument for Measuring Seasonal Winds and Earth Movements”) was invented, which is recognized as the world’s first seismoscope.
Structure and Function of the Device
This device was shaped like a large bronze vessel surrounded by eight dragon heads, each holding a bronze ball in its mouth. Below each dragon head was a bronze frog with its mouth open. Inside the vessel, a suspended pendulum was placed which, when an earthquake occurred, would move and cause one of the dragons to release its ball into the frog’s mouth. The sound of the ball hitting the frog alerted people to the earthquake and also indicated its direction.
Proof of the Device’s Effectiveness
According to historical reports, in 134 AD, this device detected an earthquake in the Longxi region of Gansu province, about 500 kilometers away from the then-capital, Luoyang. While residents of the capital felt no tremors, the device indicated that an earthquake had occurred to the west. A few days later, a messenger from the west confirmed the earthquake’s occurrence.
Mystery of the Internal Mechanism
Although there are descriptions of the device’s appearance and general operation, its exact internal mechanism remains unknown. Some theories suggest that the central pendulum’s movement activated levers that caused the release of the ball from a dragon’s mouth. However, no original version of the device survives, and modern reconstructions have been based on historical descriptions.
Historical Significance
Zhang Heng’s invention not only demonstrates the scientific advancements of ancient China in seismology but also had a profound impact on the development of future technologies in this field. This device is an example of the fusion of art, science, and engineering in ancient Chinese civilization.
