František Adam Petřina was one of the leading Czech physicists of the first half of the 19th century. He became the rector of the Charles Ferdinand University in Prague and his name is listed among the 72 important figures inscribed under the windows of the National Museum. His work was devoted to electricity, magnetism and telegraphy. Among other things, he is the designer of a device for interrupting electric current, known as the Petrina spiral.

The future physicist and rector of the University of Prague, František Adam Petřina, was born in Semily to the family of a poor tailor. Given the family’s financial situation, when he finished primary school he trained as a weaver. However, as he greatly longed to gain an education and spent his spare time studying all kinds of professional writings that came to hand, with the support of the vicar of Semily he enrolled at the grammar school in Jičín. He passed his final leaving examinations with distinction and enrolled at the University of Prague, where he studied mathematics, physics and astronomy. Lacking money and the support of his family he made a living as a private tutor for prominent townspeople and the aristocracy, and at one time even taught the future prince Windischgrätz. In 1836 he was finally awarded his doctorate at the university, opening the way to the academic career of his dreams. First of all he worked at the lyceum in Linz, but also spent some time in the physics office in Vienna under Professor von Ettinghausen. He gradually came to be highly renowned and was appointed professor of physics at the University of Prague, making him one of the very first Czech professors of physics in the country, as until then teachers had mainly been German-speaking professors. There, he devoted himself entirely to science. His main field was the study of electricity and magnetism, although he also worked with galvanism and was the first electrochemist in this country. He wrote theoretical works, in which he advocated the fluid electricity theory, as well as experimental works, which were most often on the design of various electrical instruments. He designed a rotating instrument, the predecessor of the electric motor, he designed and constructed an electromagnetic machine for generating electric current, as well as a battery, and improved the telegraph machine. One of his most important inventions, which was used in electrical engineering for many decades after his death, is undoubtedly the Petřina spiral – a device for interrupting current.

Keywords: physics; physics; mathematics; magnetism; electrochemistry; Petřina spiral