Practical Problems of Electromagnetism, Collection of the Division of Technical Sciences of the Academy of Sciences of the USSR, Moscow–Leningrad, 82 pp., 1939.

This collection, containing eight articles, is the second in this series. In it, an article by E. G. Shramkov illuminates the question of establishing standards for magnetic units in the USSR. This article describes the established standards for magnetic-field intensity, magnetic flux, and magnetic moment. The realization of these standards is the first in metrological practice, since international agreements have until now left open the question of standards.

In an extensive article, V. K. Arkad’ev sets forth two methods for calculating the skin effect in ferromagnets. This work is important in connection with the large losses in the ferromagnets of electrical networks. Therefore, it considers the phenomena of magnetization of a plate and a cylinder in fields of various types. The theory developed makes it possible to precompute the skin effect with sufficient accuracy for various practical cases.

In another article, V. K. Arkad’ev shows that magnetic spectra, which follow the general theory of passive spectra, are useful to take into account when drawing up technical specifications for ferromagnets.

A. S. Zaimovskii’s article on magnetic measurements of high-coercivity alloys raises a number of questions of a metrological character.

K. M. Polivanov considers the magnetization of shielded ferromagnetic cores in an exciting oscillatory field, which has a direct bearing on the determination of lightning currents.

R. V. Telesnin describes the results of an investigation of the Helmholtz pendulum, which was used to measure the inductance of certain types of ballistic galvanometers. This inductance, as shown in the second article by the same author, proves to be of the order of \(10^{-3}\)—\(10^{-4}\) henry.

The collection concludes with an article by O. I. Veletskaya and V. M. Goitannikov on measuring the magnetic permeability of transformer steel and permalloy at audio frequencies and in weak fields.

N. Nikitin, Moscow