should of course be freely shaped for the best sounding of the vowels.
For the vowel "a" as in far, the mouth is rather fully opened; for "a"
as in saw, it is opened deep, that is, the mouth passage is somewhat
narrowed, so as to allow increased depth. The vowel "o," as in no, has
two forms, the clear open "o," and the "o" somewhat covered by a closer
form of the lips, Commonly, when the vowel is prolonged, the initial
form, that is the open "o," is held, with the closed form, like "oo" in
moon, touched briefly as the tone is finished. So with long "i" (y), as
in thy, and "ou," as in thou--the first form is like a broad "a" as in
far, with short "i" (sit) ending the "i" (y), and "oo" (moon) ending
the "ou." This final sound, though sometimes accentuated for humorous
effect, is usually not to be made prominent. The sound of "oi," as in
voice, has the main form of "aw" as in saw, and the final form in short
"i," as in pin. The vowel "u" is sounded like "oo" (moon) in a few
words, as in rule, truth. Generally, it sounds about like "ew" in new
or mew. In some of the forms the front of the mouth will be open, in
some half open, and in some, as in the case of long "e" (meet), nearly
closed. Whatever the degree of opening, the jaw should never be allowed
to become stiffly set, nor the tongue nor lips to be held tight, in any
degree or way. These faults cause a tightening in the throat, and
affect the character of the tone. It will generally be advantage to the
tone if the lips are trained to be very slightly protruding, in bell
shape, and if the corners of the mouth be not allowed to droop, but be
made very slightly to curve upward. The tongue takes of course various
positions for different vowels. For our purposes, it may be sufficient
to say that it will play its part best if it be not stiffened but is
left quite free and elastic, perhaps quite relaxed, and if the tip of
it be made to play easily down behind the lower teeth.

Since voice has here been discussed in an objective sort of way, it is