Chinese earthquake detector,artwork. This device was invented around 132 A.D.,by Zhang Heng. It consists of a copper-domed urn with dragons' heads circling the outside,each containing a bronze ball,and a pendulum hung from its top inside. When the Earth shook,the pendulum would swing,knocking a ball from one of the dragon heads into the open mouth of a bronze toad below. The direction of the earthquake's epicentre could be determined from which ball had been released | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Hks, Gary |
Taille de l’image : | 3780 px × 2953 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |