Universal Encyclopedia
Who invented the seismograph?
The first earthquake detector was built by the Chinese scholar Zhang Heng in 132 CE: a bronze urn ringed with eight dragon heads, each holding a ball above a toad — a tremor dropped the ball, pointing at the quake. The modern seismograph came from John Milne in Japan, whose pendulums of about 1880 first recorded ground motion faithfully.
Last updated: October 2026
Zhang Heng's device could reportedly detect distant quakes the capital could not feel — court records describe officials dispatching inspectors toward the indicated direction. Milne's instruments, recording shaking on smoked paper, founded seismology as a science: for the first time, earthquakes left a written trace.