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A HISTORY OF ACOUSTICS TEXTBOOKS
Sound (1925), followed Rayleigh’s sequence of topics. In his preface, Lamb expresses his hope that “the book may fairly be described as elementary and that it may serve as a steppingstone to the study of the writings of Helmholtz and Lord Rayleigh, to which I am myself indebted for almost all that I know of the subject.”
In that same preface, Lamb is explicit in his neglect of “experimental methods” that he claims are “lying outside my province.” Two features of Lamb’s treatment that are
sadly absent from subsequent textbooks are his appli- cation of the approximation techniques developed by Rayleigh in The Theory of Sound and Lamb’s discussion of the elasticity theory before addressing waves in thin bars.
Philip Morse
By the mid-1950s, Morse’s position as a leading American theoretical physicist was established by his publication, with Herman Feshbach, of the two-volume Methods in
Theoretical Physics (Morse and Feshbach, 1953). Five years earlier, Morse published his second edition of Vibration and Sound (Morse, 1948). That textbook had
a much greater long-term influence over acoustics edu- cation than might be appreciated because it was the template for Fundamentals of Acoustics (Kinsler and Frey, 1962). The theoretical focus of Morse’s approach was clear in the title of his expanded “third edition,” coauthored with K. Uno Ingard and retitled Theoretical Acoustics (Morse and Ingard, 1968).
Vibration and Sound was written as an introductory “textbook for students of physics and communication engineering” who were attending the Massachusetts Institute of Technology (MIT), Cambridge, where Morse had been teaching a course on acoustics for several years before the first edition was published in 1936. As stated in the preface, one aim of his textbook was “to give the
student a series of examples of the method [Morse’s ital- ics] of theoretical physics; the way a theoretical physicist attacks a problem and how he finds its solution.” It included problems for students at the end of each chapter and began with an introductory chapter that addressed units and “a little mathematics.”
Other than the introductory (math) chapter, Vibration and Sound followed the same sequence of chapters as Lamb’s Dynamical Theory of Sound. Lamb included Fourier’s theorem as a separate chapter after his chapter
on strings, and Morse combines both in his chapter on strings. Lamb’s Chapter IX is titled “Pipes and Resonators,” whereas Morse’s Chapter VIII is titled “Standing Waves of Sound,” but this is primarily a semantic difference.
Vibration and Sound has about 50% more pages than The Dynamical Theory of Sound. The increase in its bulk was due to the inclusion of some material on electroacoustics (e.g., piezoelectric transducers, condenser microphone), electrical analogs, and some additional applications requiring more advanced mathematical techniques (e.g., the stiff string, transient response, propagation in horns, density of modes in three-dimensional enclosures, rever- beration time and steady-state response in auditoria, and normal mode frequencies for a kettle drum).
In the preface to the 1981 reprint of the second edition of Vibration and Sound by the Acoustical Society of America (ASA), Morse credited his first edition with making MIT
an acoustics research center during and after World War II. Morse claimed, in the preface to the 1981 reprint, that by the 1960s, “it appeared that the textural popularity of the book had waned” (Morse, 1948, 1981).
Kinsler and Frey
The reason for the decline in the popularity of Vibration and Sound during the 1960s was the appearance of Fun- damentals of Acoustics by Kinsler and Frey (1962), both physics professors at the Naval Postgraduate School (NPS), in Monterey, California. When their first edition was pub- lished in 1950, it was sent by the book review editor of
The Journal of the Acoustical Society of America (JASA) to Morseforreviewbecausehewastheauthoroftheleading acoustics textbook at that time. Morse refused to write a review for JASA because he felt that it was improper for him to review his own textbook (Garrett, 1990).
In fact, the bulk of Fundamentals of Acoustics was taken directly from the second edition of Vibration and Sound, although many of the applications requiring more chal- lenging mathematical techniques (e.g., scattering of sound from spheres and cylinders, modes of cylindri- cal enclosures) were absent from the Kinsler and Frey version. Several end-of-chapter problems were taken verbatim from Morse, although in the second edition, the units were changed from centimeter/gram/second (CGS) to meter/kilogram/second (MKS). The conven- tions for expression of variables were also updated (e.g.,
24 Acoustics Today • Fall 2021