Page:Elementary Text-book of Physics (Anthony, 1897).djvu/192

178 to one another. These may be produced simultaneously by the same body, and so give rise to complex tones, the character of which will vary with the natnre and intensity of the simple tones produced. It has been held that the quality of a complex tone is not affected by change of phase of the component simple tones relative to each other. Some experiments by Konig seem to indicate, however, that the quality does change when there is merely change of phase.

In Fig. 58 are shown three curves, each representing a fundamental accompanied by the harmonics up to the tenth. The curves differ only in the different phases of the components relative to each other.

Fig. 59 shows similar curves produced by a fundamental accompanied by the odd harmonics.

152. Resonators for the Study of Complex Tones.—An apparatus devised by Helmholtz serves to analyze complex tones and indicate the simple tones of which they are composed. It consists of a series