A. S. EVE and D. A. KEYS. Applied Geophysics in the Search for Minerals. Pp. VIII + 253. Cambridge University Press. 1929. Price 12 sh. 6 d.

EVE and KEYS. Applied Geophysics in Application to the Search for Ores.

This little book, written by two Canadian physicists, is devoted to the exposition of modern physical methods of mineral prospecting (magnetic, electrical, electromagnetic, gravitational, seismic, radioactive, thermal, etc.). The authors give a clear and vivid description of the theoretical and practical foundations of these methods, avoiding complicated mathematical expositions and overloading the presentation with minor technical details. These qualities make it possible to regard this book as an excellent introduction to the new and important field of applied geophysics, which in recent years, abroad and among us, has become the subject of separate instruction in most higher educational institutions (Mining Academies, Universities, Polytechnic Institutes, and others). The simplicity of the exposition and the large number of examples of the application of the methods discussed in field practice make the book interesting not only for exploration specialists, but also for geologists, physicists, engineers, and practical workers in mining.

Among the shortcomings of the book should be noted, first, a somewhat uneven distribution of the material among the individual chapters: thus, the description of electrical and electromagnetic methods, which at present are still in the stage of development and field trials, is given as much space as the well-developed and more frequently used in practice magnetic, gravitational, and seismic methods; second, the authors do not at all touch upon combined methods of exploration (for example, magnetic together with gravitational, seismic with gravitational, etc.), which are now being intensively developed and which make it possible to achieve greater certainty in the geological interpretation of geophysical observations made on the surface of the earth; and, third, the authors in general devote little attention to questions of the geological interpretation of the measurements carried out, whereas this question is of decisive importance for practice.

Despite the incompleteness of exposition indicated here, the book should be recognized as deserving the widest distribution, and its translation into Russian, with appropriate additions, is an urgent necessity that has long been ripe.

M. Polikarpov.