Who invented seismograph?

Roberts Mallet, an Irish engineer and geologist, pioneered seismology in the 1840s-50s and is credited with early seismograph development. He studied earthquake waves and conducted experiments to understand how seismic waves propagate through different materials. While John Milne later developed the modern seismograph, Mallet's foundational work established the scientific study of earthquakes. His research laid groundwork for understanding earthquake behavior and building design.