One must, next, consider the motion of the Sun. This consists of the motion inside the Milky Way plus the motion of the Milky Way with respect to the general eld of galaxies, or, as the American astronomer Edwin Hubble (1936, p. 106) prefers with respect to the nebulae". The observations of galaxies are expressed, as we saw, with respect to the Sun", and in order to have the motion of the galaxies with respect to the general eld of galaxies one might remove the motion of the Sun with respect to this same eld. We shall describe this procedure, in what follows, according to the method quantitatively prescribed by Hubble in his in uential article of 1929 and, rather clearly described in a qualitative way, in his book of 1936 entitled The Realm of Nebulae. In section 3, we apply Hubble's method to the galaxy sample of Knut Lundmark, Hubble's
contemporary at astronomy. We conclude with general remarks in section