sung on f is made up of two combined simple vibrations. One of these alone would make the long tongues of flame, but with this simple vibration exists another of three times its frequency; that is, the vibration of greater frequency is the third harmonic of the slower. As the slower vibration, making the long tongues of flame, is f, the higher
Figs. 52, 53, 54, 55, 56.
must be c" of the second octave above f. Each third vibration of this higher harmonic coincides with each vibration of f; hence each third tongue of flame is higher than the others.
Experiment 119.—In like manner the student must analyze Fig. 56 into its simple sonorous elements. Then he should, with the vibrating flame, examine the peculiarities of the various voices of his friends, and make neat and accurate drawings of the flames corresponding to them, so that he may analyze them at his leisure.
Experiment 120.—Blow your toy trumpet into the paper cone gently, and then strongly, and observe that the sound given by the trumpet is a complex one. Try if you cannot get a flame somewhat like that the trumpet gives by singing ah, through your nose, into the cone.
