the Massachusetts Institute of Technology (MIT). His departure was of course an invaluable loss for Italian physics.

Cosmic-ray studies in Italy during World War II
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Besides Rossi, a few other physicists who had been with him in Arcetri, had also started working on cosmic rays. Gilberto Bernardini and Giuseppe Occhialini, in particular, both played an important role in the field, though their scientific careers were very different one from the other: Bernardini mainly spent the 1930s and the 1940s in Italy, and he significantly contributed to the development of cosmic ray researches within the country, while Occhialini spent many years abroad, where he gave fundamental contributions. We have already discussed Occhialini’s working with Blackett on cloud chambers in Cambridge, and we will see more about his work in the followingsections.

As for Bernardini, he carried out his first researches on cosmic rays in the early 30s in Florence, where he collaborated with Sergio de Benedetti and Daria Bocciarelli. He studied the typical cosmic ray questions of those years, as for instance the absorption of the penetrating radiation at different zenithal inclinations, the influence of the earth magnetic field on the penetrating radiation, and cosmic ray showers (see in particular [@BernardiniDeBenedetti1933; @BernardiniBocciarelli1934a; @BernardiniBocciarelli1934b; @BernardiniBocciarelli1935a; @BernardiniBocciarelli1935b; @BernardiniBocciarelli1935c]). He was assigned in 1937 a chair in Camerino, but a few months later, in 1938, he already moved to the University of Bologna. However, as the Institute of Physics in Bologna was not suitably organised for extensive research activity, Bernardini spent several days a week in Rome, where the scientific activity went