Modern seismograph

Advancements were made in developing the first modern seismograph to measure earthquake strength, using a horizontal pendulum system. This development marked the beginning of modern seismology and led to the establishment of seismograph chains worldwide.
 John Milne England 1880 Modern seismograph

Advancements were made in developing the first modern seismograph to measure earthquake strength, using a horizontal pendulum system. This development marked the beginning of modern seismology and led to the establishment of seismograph chains worldwide.