'Around 132 A.D. Chinese scientist Chang Heng invented an early form of this earthquake detector'
seismograph
GEOLOGY: Around 132 A.D. Chinese scientist Chang Heng invented an early form of this earthquake detector
Around 132 A.D. Chinese scientist Chang Heng invented an early form of this earthquake detector
Around 132 A.D. Chinese scientist Chang Heng invented an early form of this earthquake detector
GEOLOGY
seismograph
GEOLOGY