By considering the influence of the earth's magnetic field on the motion of charged particles (electrons, protons, etc.) coming to the earth from all directions in space, it is shown that the experimental variation of cosmic-ray intensity with magnetic latitude, as found by Compton and his collaborators, is fully accounted for. The cosmic radiation must contain charged particles of energy between limits given in the paper. The experimental curve may be represented by a suitable mixture of rays of these energies, but it is not at all excluded that a part of the radiation may consist of photons or neutrons. For predominantly negative particles there must be in the region of rapidly varying intensity a predominant amount of rays coming from the east, and conversely for positive rays. Because of the fact that in regions near the magnetic equator there is a predominance of rays coming nearly horizontally, the absorption by the atmosphere may be increased. Finally the fact that Compton's result definitely shows that the cosmic rays contain charged particles gives some support to the theory of super-radioactive origin of these rays advanced by one of the present authors.