TEMPO.CO, Jakarta – Seismograph is a device that is installed in the ground to detect earthquakes, as quoted from the United States Geological Survey. The device is equipped with data recordings or seismograms.
Quoting from the Michigan Technological University website, the first seismographs were made by experts astronomy and the Chinese mathematician Zhang Heng in 132 AD. At that time, Heng called the device an earthquake measuring device.
Heng’s seismograph is in the form of a bronze jar with an ornament of 8 dragons with a ball in its mouth. When there is a shock the ball will fall and make a loud sound signaling an earthquake will occur.
The modern horizontal seismograph was created in 1880 by the British geologist John Milne. Citing The Inventors, the tool made by Milne is more sophisticated for detecting shocks using a long pendulum mounted on a record needle.
When there is a shock, the needle will stroke a pattern that detects the direction and intensity earthquake. The physicist Sir James Alfred Ewing made improvements to the pendulum so that it could record vibration waves for a long time. Improvements made by Ewing replace the pendulum support shaft with elastic wire to avoid friction. That is so that the pattern that is etched is more accurate.
NAUFAL RIDHWAN ALY