Louis Leprince-Ringuet, an expert in cosmic rays and a member of the first ICTP ad-hoc committee that helped design the Centre's research and training activities in the 1970s, recently passed away. After completing engineering studies in telecommunications at Ecole Superieure d'Electricite in Paris in the early 1920s, he switched to physics in 1929 and subsequently obtained a doctorate from the University of Paris. Leprince-Ringuet's most noteworthy research, conducted in collaboration with Pierre Auger, confirmed that cosmic rays are comprised of charged particles. In 1936 Leprince-Ringuet became professor of physics at Ecole Polytechnique in Paris, where he played a leading role in the revival of physics in postwar France. After strongly supporting the creation of CERN, he chaired CERN's scientific policy committee.