What is used to record the shaking of an earthquake?

A Seismograph is an instrument designed to record earthquake shocks mechanically. Seismology is the study of earthquakes, one proficient in this science is called a seimologist-= like Dr. Richter of scale fame. among the various manufacturers of Seismographs is the Sperry Company, better known for Gyroscopes, gyro-compasses and the like. I believe both the Fordham and Oberlin seismological observation stations use Sperry instruments. Shake, Rattle, and Roll- Three axis models.