50 JOURNAL OF PROCEEDINGS. 
The number of any note in the ha:monic series gives also its 
number of vibrations by multiplying those of the fundamental tore. 
These overtones can sometimes be detected by the ear unaidcd, but 
they can be plainly brought out by resonators tuned to tle notes 
which are wanted to be detected. 
It is the presence of these oveitcnes in varying quantity and 
power that makes different qualities of fundamental tone. We all 
know the different qualities of tone of pianoforte, violin, horn, flute, 
to say nothing of the human voice ; and it has been proved that 
these shades of difference are all due to the presence (with the 
fundamental tone) of varying strengths of different overtones. One 
man’s mouth and throat differs in quality and shape from another’s 
in various minute ways, which tend to reinforce different overtones 
in different voices, and produce in that manner the different quality 
or distinguishing ‘‘timbre’ of each voice. 
It has been discovered furthermore that vowel-sounds are 
nothing more than different qualities of fundamental tone produced 
by the same conditions, This has been proved by Helmholz, the 
great scientist, by an experiment made with flute pipes and tuning- 
forks of different pitch, representing the various notes of the 
harmonic series, which are needed to join with the ground tone to 
make the vowel-sound desired. 
Experimenting with tuning forks for the first eight members of 
the harmonic series, the results were briefly as follows: The prime 
tone sounded alone gave a dull U sound—duller than possible in 
speech. The second and third sounded feebly in addition became 
more like OO. A fine O was produced by making the fourth 
strong, the second, third and fifth weak, and the prime tone some- 
what subdued. O, as in zo?, by making fifth, sixth, seventh, eighth 
loud and subduing the rest. A passably clear A by making the 
fourth and fifth loud and subduing the rest, and a sort of E by 
reinforcing the third and sounding the rest feebly. 
In precisely the same way as with the vowel-sounds it is 
possible to imitate the quality of tone of organ pipes and orchestral 
instruments. The nasal quality of the clarionet is made by using a 
series of unevenly numbered overtones ; the softer tones of the horn 
by using the full chorus of overtones. 
