A. W. WOOD. A Text-Book of Sound. G. Bell and Sons, London, 1930. Pp. 519 (about 33 sheets), 156 figs.; price 25 shillings.

A. WOOD. Course in Acoustics.

The literature on acoustics has been enriched in the past year by two new textbooks, one in English and the other in German (see the following review). The appearance at once of two fairly extensive textbooks covering the entire broad field of acoustics serves as an indication of the great accumulation of new material in recent years and also speaks of a considerable expansion in the circle of persons interested in acoustics.

A. Wood’s textbook (not to be confused with R. W. Wood, the well-known American researcher in optics) is written in an elementary form: difficult theoretical questions are hardly touched upon; only elementary mathematical analysis is used, and even that only in the introductory part of the book. The chief attraction of the book is its abundant experimental material, illustrated by a large number of excellently executed drawings from recent works.

The author of the book is known for his research in the field of experimental acoustics; he worked especially much in the field of hydroacoustics in the laboratory of the British Admiralty at Teddington. The author’s scientific interests have left a definite imprint on the book: questions of military acoustics and, in particular, hydroacoustics are illuminated especially attentively and are read with special interest. Conversely, a number of important questions that apparently stand aside from the author’s interests are set forth somewhat briefly and dryly. The material on questions of the analysis of speech and musical instruments is very meager; there is no section on tonal systems; questions of hearing are weakly illuminated. The basic questions of the theory and practice of “electroacoustics,” i.e. questions of the loud transmission of speech and music, the theory and construction of loudspeakers, microphones for modern transmission, are very sparsely treated. Important questions concerning the radiation of sound, nonlinear oscillations, etc., are only briefly touched upon. I shall note one error by the author: the question of the velocity

propagation of a wave in a plate (p. 158 below) is presented incorrectly; this velocity depends on the wavelength and is not determined by the expression given by the author.

A. Wood’s book contains, on the whole, very valuable material on physical and technical acoustics and can serve as a good aid for persons working in this field, as well as for students preparing in the specialty of acoustics.

The book is provided with an index and complete footnote references to the literature.

S. Rzhevkin