Dudes around 132ad China were smart....

In 132ad China during the Han Dynasty a man named Zhang Heng invented the seismograph.    A device to show when an earthquake took place and how intense it was.   A mild one dropped one or two bronze balls from the dragon's mouth to the frog's mouth.    A real bad one released more.   Very smart people.

                   This is a remake of the original and sells for around $4000.00.  
                   Has gold balls.   Very nice idem.   If you see one, now you know what it is.
                   A original Bronze one would be priceless, keep an eye out for it.