Jaroslav Jiljí Jahn

Jaroslav Jiljí Jahn was one of the nation’s most important geologists, who worked particularly at the Czech Technical University in Brno, but also collaborated with the University of Vienna. He was the author of a great many geological findings from Bohemia and in 1899 became one of the first professors of geology in the country.

Jaroslav Jiljí Jahn was born in 1865 to the family of Jiljí Vratislav Jahn, a prominent patriotic politician, writer and teacher. He gained an elementary education at the real grammar school in Pardubice, attended secondary school in Chrudim and then enrolled to study a university degree at the Faculty of Arts in Prague, where he was first awarded a doctorate in philosophy and later also in geology and mineralogy. His versatile talent brought him into contact with some prominent scientists of the time. He collaborated with the leading geologist Antonín Frič, and also studied botany under Ladislav Čelakovský. He gradually came to focus his academic career on geology and soon became vice-chairman of the Association of Geologists and participated in professional geological surveys. He left the university for a brief time and taught at secondary school in his hometown of Pardubice, to eventually return to academia first as a student and later as geology assistant at the University of Vienna. There, he was also involved in geological mapping and was entrusted with completing Joachim Barrande’s work Systême silurien du centre de la Bohême. In 1899 he finally returned to Bohemia and became a professor of geology and mineralogy at the Czech Technical University in Brno, where he founded the Institute of Mineralogy and Geology. He was a member of a number of professional associations and was one of the founders of Czech mineralogy. He was particularly interested in the stratigraphy, tectonics and palaeontology of Bohemia, Moravia, Silesia and Carpathian Ruthenia and was also a leading figure in the study of mineral springs. It was at his instigation that work began to drill boreholes in Mariánské Lázně and Rajecké Teplice. 

BAHENSKÁ, M.: Jaroslav Jiljí Jahn: (1865–1934). Akademický bulletin Akademie věd České republiky, 10/2009, s. 34

Jaroslav Jiljí Jahn (Author: Archive MUA AV ČR)