The article presents biographical entries and professional achievements of three makers of scientific instruments from the Jagiellonian University in Krakow, who were related with each other: Roman Calikowski (1886–1940), his brother Ludwik Calikowski (1889–1961) and Roman’s son Roman Julian (1915–1986). These mechanics worked at the Jagiellonian University between 1904 and 1962/1963. Two brothers, Roman and Ludwik, were associated with the University throughout their professional life. During their tenure, the University’s research in the field of low temperatures continued, which was initiated in 1883 by Zygmunt Wróblewski (1845–1888) and Karol Olszewski (1846–1915). The main scientific achievement of these researchers was the liquefaction of oxygen, nitrogen and other solid gases. In the late 19th century, Kraków was an important center of cryogenic research, in which the mechanics played important role. Roman Calikowski made instruments for liquefying gases according to the design of Karol Olszewski. Liquefiers from his workshop were ordered, inter alia, by universities in Chicago, Mumbai and Madrid. A few instruments from his workshop have been preserved in the collections of the Jagiellonian University. Ludwik Calikowski worked as a maker of scientific instruments in a university cryogenic laboratory. He served and maintained the apparatus for liquefying gases and made instruments, although none have survived to this day. Roman Julian Calikowski took over the workshop after his father. Until 1950 he ran his own company, which made simple small microscopes, surveing instruments, psychotechnical devices and other instruments. After moving to Warsaw, he devoted himself to scientific work.

Roman Calikowski’s products, especially cryogenic apparatus, represented a high level of workmanship and safety. This is evidenced by numerous orders for its liquefiers submitted by foreign laboratories. The company of Roman Julian Calikowski, apart from a wide range of instruments it offered, used to repair photographic and measuring equipment.