What’s even model of Chang's seismograph? So far, justly a few 196 words in After the Han Dynasty, which seal to Chang’s seismograph and his in history as a code. 

The overhang-swing of principle

Chang's Seismograph construction thinking has been enlightened by chandelier of period of Han at archaeology work.

There one thinking difference with upright stick thinking in every country’s Seismograph model being noted by FenRui. “May or not be quake is occur with look up see chandelier to know”. Because of a lofty overhang chandelier very sensitive to ground plane motion and it is shaking repeatedly by action of inertia force during a quake happen. In 19 century, a“zhong you du zhu”of ancient Chinese seismographic phrase was translated “one stick in the middle and it is hanged” by the ancestor Ernt of modern seismology .

How seismography had been invented by changheng with made use of an overhang-swing of principle on BC 1800.The evidence of chandelier to show it existed in period of Han by archeology work.

To be Chang's seismography, overhang-object with four features: first, while quake is occurring, that is moving. Second, it very sensitive and third it's so often shaking that easy to notice. Fourth , according of After the Han Dynasty:“ quake is occurring then jar is shaking ”then jar is shaking ,a head of dragon device will be operating and spiting a ball, a shaped clam device is holding a ball with mouth. Base on these descriptions, we conclude that overhang-object to observe ground level motion. Skilful arranged two objects that one is“ji ”   another one is “guan”。The latter is greatest important a part of latch of ancient for recreate it. “du zhu” is greatest important a spare part of structure in inner design. In historical records of it take place resonance by earthquake wave effluences to all of “du zhu ” begin work. Then indicate a head of dragon device would spit a ball during that way of place where is happen to quake and except other sevens. How did the Chang’s seismography do that?

Just only a Chinese phrase which “shi guan fa ji” in historical records. Refer to this phrase the eight part of heave was created within “du zhu” by FengRui but their power of movement too lightly to shake with “du zhu”. Although heave parts can trigger a head of dragon device and it would be spit a ball. One cause of eight touching-point has 45°to each other . In addition to an factor of inertia of “du zhu” we couldn’t get a effect as “ yi long fa ji qi shou bu dong” in Chinese phrase .(Just only one a head of dragon device is operating without other sevens when the earthquake to happen.

FengRui restudies a few key words in historical records and something comes into his notice “shi guan fa ji, ji guan qiao zhi, jie yin zai zunzhong”.( “ trigger and latch section 、skilful arranged latch and trigger 、latch and trigger part both of hidden in jar.”) what’s even real mean “ ji guan ”? He pay an attention to “shi” 、“fa”、 “ji” and“guan” are meaning verb and noun separately .

In other word, “ji” and “guan” is different two objects.

It does very easy understand to “ji” and what does even mean “guan?”Thus, a lot of works has been done by FengRui and finally get an answer of “guan” which is a latch in ancient. In order to solve to short of power of movement problem in objects, a small spare parts of trigger usually was adopted to increase movement energy by ancestor. The spare part of trigger called “guan”.

In fact, one greatest secret is a sensitive spare part of trigger - “guan” and that’s why Chang’s seismography exactly forecast earthquake. A spare part of trigger -“guan” is in the under of spare part of “du zhu” very small a cone platform. When earthquake wave from where place is take happen quake, A spare part of trigger and spare part of “du zhu” meeting in passage. At the end of passage, there is a structure of lever named “ji” which is jointed a head of dragon device.  

Reborn in the world

Historical records by proved. Well known Chang’s seismography is famous for the LongXi quake on BC 134 years.FengRui is refers to After the Han Dynasty, that center of quake located near at nowadays Gansu tianshui. It is far way 600km Luoyang. The Luoyang quake level is 3 to 4 N……  With so precise date tested, recreated Chang’s seismography is works at successful when quake coming. Farther, workers are test recreated seismography in real quake conditions and get a successful.

Fengrui proves to world that the earliest seismography is not a legend and absolutely exist even works. It’s not exaggeration to say that Chang’s seismography is answer to challenge in domestic and abroad ,also it fund a missing loop to reborn with changheng and his seismography.