The Student's Handbook of Acoustics

Abstract

WE are not quite sure what the title of this work is. The title just given is from the lettering on the back. Within the covers appears a second title, “Musical Acoustics,” and on the actual title-page appears the triple announcement, “The Student's Helmholtz,” “Musical Acoustics,” and “The Phenomena of Sound as connected with Music.” The book itself may without unfairness be described as an “arrangement,” or rather as a “pot-pourri,” inasmuch as it resembles those musical compositions in which some of the fragmentary themes of one or more great masters are dished up for the public in some new or popularised setting, consisting of commonplaces of a more or less florid type. About 80 per cent, of the pages before us consist of clippings and quotations taken verbatim et literatim (and in quotation marks be it added) from the works of Helmholtz, Stone, Pole, Tyndall, and Sedley Taylor, interspersed with a connective-tissue woven from the “author's” own brain. We have found this ingenious fabric very remarkable reading, and have gleaned a number of new facts from it. We have learned, for example, that the transmission of verbal messages, prayers, hymns, and sermons through the telegraph wire by the telephone must be held to “prove that air is not the only medium through which sound-impulses can pass.” We find our author declaring on p. 80 that the reason why so romantic a name as the “syren” should be applied to so matter-of-fact an instrument does not appear; while on p. 98 he seems to have made the discovery that the name is a misnomer, because “Homer's ερνπηoδ” (sic) were not endowed with the power of singing under water as this instrument can. Our author is very unhappy in dealing with equal temperament, and complains tha nearly all writers on temperament, with the exception of Mr. Ellis, describe it as dividing the octave into twelve precisely equal semitones, “without explaining that these semitones are not absolutely equal.” That the perfect equality of the theoretically equal temperament is never attained in practice is indeed true; but why does our author find fault with writers on temperament for stating the exact theory? His accusation against Dr. Stone for palpable misuse of language (on p. 359) is utterly out of place, and only shows that the author has not comprehended the true meaning of a musical interval as defined by a ratio. He appears not to know that if an octave is divided into twelve exactly equal geometrical parts or ratios, the differences between the successive terms of the ratios are not, and cannot be, arithmetically equal to one another. Hence his attack on the perfectly unexceptionable statements of Dr. Pole and Dr. Stone. The diagrams with which the work is interspersed consist principally in pictures of syrens and in copies of wave-forms taken from Mr. Sedley Taylor's “Sound and Music,” and spoiled by drawing them as if made up of semicircles pieced together. The wave-form given on p. 266 to illustrate beats does not show the wave-form of the beat at all: and though the author gives on p. 102 a wave-form which illustrates a beat admirably, he appears not to know it, as he passes it by as being merely one of a few different forms of tracing which a vibroscope can register. But we have said, enough to justify us in having at the outset pronounced “The Student's Helmholtz” to be what we called it—a pot-pourri—or, in the plain English tongue, a hash.

The Student's Handbook of Acoustics.

By John Broadhouse. (London: William Reeves, 1881.)