Abstract
Teller-Richtmyer's theory of the origin of cosmic radiation is discussed. It is found that the magnetic field ("trapping field"), which they postulate in order to explain the isotropy of cosmic radiation, must be toroidal and have an extension of about 0.1 light year. A field of this type may be produced by the motion of the solar system relative to interstellar matter. The theory gives the energy spectrum and total intensity of cosmic radiation.