Radioactivity of Rocks and Ionization‐Balance of the Atmosphere

It is shown that if one computes the ionization produced by gamma rays from radioactive substances in rocks and soil from figures given recently as average values for representative classes of rocks by Evans and Goodman the expected ionization turns out considerably smaller than the one actually observed by placing ionization‐vessels over land and over water. Two methods are developed theoretically which make it possible to determine simultaneously the residual ionization, the effect of cosmic rays and of the gamma rays from radioactive substances in the Earth, and to separate these components of the total ionization. Comparisons of ionizations determined by one of these methods with values computed from given figures of radioactive material in well‐defined rocks are planned.