Seismologist. After graduating from the Department of Physics of the Imperial University of Tokyo (later, the University of Tokyo) in 1890, he went on to graduate school and majored in seismology and meteorology. As a result of the Nobi Earthquake, the Earthquake Investigation Committee was established in 1892, and he participated in its first meeting as a member. In the following year, his electric seismometer was exhibited at the World’s Columbian Exposition in Chicago. From 1890 to 1892, he studied abroad in Europe, and after returning to Japan, he assumed a professorship at the College of Science of the Imperial University of Tokyo. His achievements include the production of various seismometers, the discovery of seismic belts, the measurement of tsunami, tide levels and microseisms, and seismic measurements of buildings.