The ionosphere, geomagnetism and aurorae were studied. Aleksey Tillo also authored a number of works on geomagnetism and meteorology. Its researchers participated in international projects in the areas of astronomy, geodesy, geomagnetism and meteorology. In addition, he had interests in theology, philosophy, history, mathematics and geomagnetism. Bartels was the first President of the International Association of Geomagnetism and Aeronomy (IAGA). The Dst index is compiled and archived by the World Data Center for Geomagnetism, Kyoto. Scientists constantly measure the strain in rocks, heat flow, microseismicity, and geomagnetism around Parkfield. Applications include geomagnetism, magnetotellurics and seismology. The 165-year-old building served as office space for the Indian Institute of Geomagnetism. Their father, Robert Were Fox, was an FRS with interests in mineralogy, metallurgy and geomagnetism. The Indian Institute of Geomagnetism currently operates Ten magnetic observatories. In later years the observatory also made observations on stars and geomagnetism. Bhattacharyya joined the Indian Institute of Geomagnetism (IIG), Mumbai in 1978. His research has also involved geomagnetism, solid earth geophysics, and some oceanography. A geomagnetism sensor provides orientation with respect to Earth's magnetic field.