IT is not a great many years ago since the satisfaction of acoustical requirements was purely a matter of empiricism. Here and there a scientific worker such as Rayleigh could explain the underlying principles; but seldom could an acoustic triumph, like the Free Trade Hall, Manchester, be acclaimed, nor could dependent data be obtained even from that; consequently, neither analysis nor synthesis came to our aid and architects were but blind leaders of the blind. Wallace Sabine, however, introduced a new era into acoustical research, and now it is by no means uncommon to secure success. Prof. Floyd Watson's treatise is a welcome contribution to the synthetic treatment of the subject. Whether it is better to secure original acoustic satisfaction or to correct acoustic failures, admits of no argument. In either case, the author's work has the merit of showing the way. The value of wires and sounding boards is almost entirely discounted in the light of modern investigation. The concluding argument is interesting, in its recommendation that Sabine's advice (remembering the varying size of the audiences) to effect a compromise, is the desirable procedure. For practical purposes the use of the different soundabsorbing coefficients is of the greatest value.
Acoustics of Buildings: including Acoustics of Auditoriums and Soundproofing of Rooms.
Prof. F. R. Watson. Second edition, revised. Pp. x +155. (New York: John Wiley and Sons, Inc.; London: Chapman and Hall, Ltd., 1930.) 15s. net.