200 Years in 24 Hours

Observatory Chronograph – the Seismograph

A seismograph is a measuring instrument equipped with a ground motion sensor. Recordings of seismic waves served to note the disturbances sustained by high-precision clocks during earthquakes and to correct them accordingly.

The Quervain-Piccard seismograph dates from 1930. It operated until 1980 and was able to detect earthquakes on the other side of the planet.