Chapter 324 armillary sphere and seismograph

Zhang Heng (78-139 AD), courtesy name Pingzi, was born in Xi'e County, Nanyang County (now Nanyang, Henan Province), and was a famous astronomer in the Eastern Han Dynasty.His most important achievements are writing "Lingxian", making armillary spheres, building seismographs, and researching calendars.In addition, he is also a master of mechanical technology, a talented writer and painter, and has a profound influence on the development of later generations of culture. Zhang Heng's outstanding contribution to the development of astronomy in our country lies in his creation of the armillary sphere.Zhang Heng designed and made the armillary sphere to supplement his astronomical theory - the theory of armillary sky.

The "armillary sphere" created by Zhang Heng is used to demonstrate the "uniform phenomenon" of celestial bodies. It consists of a bracket and a hollow copper ball with a diameter of more than four feet spread all over the surface. It is similar to a modern celestial globe. official. Zhang Heng has also made great achievements in the field of seismology. His masterpiece is the invention of the Houfeng Seismograph, which is astonishing in the past and the present.The Houfeng Seismograph, also known as the Seismograph, was made in the first year of Yangjia (AD 132). It was the first instrument in the world to observe and report earthquakes.The seismograph is made of fine copper, like an oval wine bottle, with a diameter of 8 feet.There are "mountain turtles, birds and beasts" cast outside the instrument, symbolizing the mountains on the ground and the twenty-eight constellations such as the green dragon, white tiger, red bird, and basalt in the sky.There are eight trigrams and seal characters engraved on the eight directions outside the body, expressing the spirit of the eight directions.There are eight dragons attached to the body, each with its head facing in all directions, symbolizing yang; eight toads raise their heads and open their mouths below the dragon's head, symbolizing yin.This constitutes the dialectical relationship between yin and yang, up and down, movement and stillness.There is a tall and thin copper pillar in the body of the instrument, which is called "Duzhu".The capital column is in the upright position in the body of the instrument, and it is designed according to the ancient theory of Tianzhu.There are eight sets of slides beside the pillars. The slides are connected to the faucet through a lever, and the mouth of the faucet contains copper balls.During an earthquake, the inclined column falls to the slideway in the direction of the earthquake, and the lever is pushed to the end to trigger a tooth machine like an engine. The dragon head opens, and the copper ball falls into the mouth of the toad below, saying "when " a sound.The master of ceremonies can report the direction of the earthquake according to the direction of the falling ball.

This instrument is ingeniously conceived and precisely manufactured. According to historical records, "Testing it with facts will make it fit like a god".It can not only detect earthquakes that people can feel at close range, but also earthquakes that occur thousands of miles away!