L. V. MYSOVSKY. Cosmic Rays. Series “The Newest Trends in Scientific Thought,” no. 16, State Publishing House, Moscow—Leningrad, 1929, 131 pp., price 1 rub. 65 kopecks.

The problem of cosmic radiation has attracted interest and attention, especially in recent times, when, thanks to Millikan’s work, an estimate was made of the spectral composition of cosmic radiation, giving grounds for important cosmogonic conclusions. Readers of Uspekhi are already familiar with these questions from several articles published in this journal. L. V. Mysovsky’s small book very opportunely provides readers with more detailed information about the phenomena of cosmic radiation and the methods of studying them. After a brief exposition of the necessary theoretical information on the absorption and scattering of X-rays and gamma rays and an introduction of the reader to the basic methods of measurement (Chapter I), the author devotes the next six chapters to a fairly detailed account of experiments intended to clarify the properties, spectral composition, and place of origin of cosmic rays. The final chapter is devoted to hypotheses concerning the origin of cosmic radiation. It is to be regretted that this chapter, which is of the greatest general interest, has turned out to be rather brief. Apparently the book went to press before the appearance of some of the latest work in this field.

The author himself takes an active part in the study of cosmic rays, and this has even left a certain imprint on the book under review. The exposition of some experimental methods and individual experiments may perhaps be considered excessively detailed. Nevertheless, the book will undoubtedly be read with interest by all who follow the latest advances of scientific thought. The book’s appearance, drawings, and photographs, obtained by D. V. Skobeltsyn and adapted for viewing in a stereoscope, are executed quite well.

Gr. Landsberg