František Nušl

After high school in Jindřichův Hradec, he studied physics and astronomy in Prague, where he met among others the future president of Czechoslovakia, T. G. Masaryk, the linguist Jan Gebauer and the historian Josef Goll, with whom he collaborated on Otto's encyclopedia.

In 1898 Frič bought a large piece of land in Ondřejov, 50 km south-east from Prague, where they established an astronomical observatory.

In 1928 Frič dedicated the well-equipped Ondřejov Observatory to the Charles university and to the Czechoslovak state and Nušl became its first head.

He was a member and temporarily vice-chairman of the International Astronomical Union and participated in establishing the popular Štefánik's Observatory on the Petřín hill in Prague.

The method was based on the properties of mercury horizon and allowed to establish local coordinates with an error about 10 m, surpassed only much later by satellite navigation.