282 PLEASANT WAYS IN SCIENCE. 



various vocal sounds are produced, without changing the 

 pitch or intensity of the sound actually uttered. Calling the 

 fundamental tone the first tone, the overtones just mentioned 

 the second, third, fourth, etc., tones respectively (after Tyn- 

 dall), we find that the following relations exist between the 

 combinations of these tones and the various vowel sounds : 



If the lips are pushed forward so as to make the cavity 

 of the mouth deep and the orifice of the mouth small, we 

 get the deepest resonance of which the mouth is capable, 

 the fundamental tone is reinforced, while the higher tones 

 are as far as possible thrown into the shade. The resulting 

 vowel sound is that of deep U (" oo " in " hoop "). 



If the mouth is so far opened that the fundamental tone 

 is accompanied by a strong second tone (the next higher 

 octave to the fundamental tone), we get the vowel sound O 

 (as in " hole "). The third and fourth tones feebly accom- 

 panying the first and second make the sound more perfect, 

 but are not necessary. 



If the orifice of the mouth is so widened, and the volume 

 of the cavity so reduced, that the fundamental tone is lost, 

 the second somewhat weakened, and the third given as the 

 chief tone, with very weak fourth and fifth tones, we have 

 the vowel sound A. 



To produce the vowel sound E, the resonant cavity of 

 the mouth must be considerably reduced The fourth tone 

 is the characteristic of this vowel. Yet the second tone also 

 must be given with moderate strength. The first and third 

 tones must be weak, and the fifth tone should be added with 

 moderate strength. 



To produce the vowel sound A, as in " far," the higher 

 overtones are chiefly used, the second is wanting altogether, 

 the third feeble, the higher tones especially the fifth and 

 seventh strong. 



The vowel sound I, as in " fine," it should be added, is 

 not a simple sound, but diphthongal. The two sounds whose 

 succession gives the sound we represent (erroneously) by a 

 single letter I (long), are not very different from "a" as in 



