ABSTRACT
Nevertheless, cosmic rays remained something of secondary importance for astronomy and this is quite natural: cosmic rays were only observed near the Earth, and because of the high degree of their isotropy no evidence existed as to the character and location of their sources. This situation is analogous to the one which would exist in optical astronomy if one did not observe separate stars and nebulae but analyzed only the spectrum of all the sources taken together. True, before 1950 there did appear some papers anticipating future developments. Among them one should mention the supposition by Baade and Zwicky (1934) [3) of the connection of supernova flares with the formation of neutron stars and with cosmic-ray generation; and we should also mention the paper by Fermi (1949) [4) devoted to the acceleration of cosmic rays when they propagate in interstellar magnetic fields.
