ABSTRACT
Interest in mapping not merely the heavens but also the lands, a special concern of modern civilizations, increased mainly at the end of the eighteenth and beginning of the nineteenth centuries. Although knowledge about geomagnetism was old, only in the nineteenth century was it possible to improve precision measurements of magnetic intensity. After Carl Friedrich Gauss (1777–1855) established an international Magnetic Union (Magnetische Verein) based in Göttingen in 1836, a network of magnetic observatories promoted a worldwide collaboration in order to get a deeper understanding of Earth’s magnetism. While the participation of England, Russia, and the United States in this network is better known, Portugal also participated in this Union. This article aims to show how Portuguese institutions were influenced by the development of this branch of science and to detail their participation in the international geomagnetic network in the nineteenth century.
