The second chapter in this volume is Smoothness of Voice. When the mind
of the speaker is steadily concentrated upon the thought for the
exclusive purpose of causing other minds to act upon it, the tones under
the repetition of drill gradually tend to evenness. To get this result,
I once worked with pupils to make them hold the diaphragm and abdominal
muscles in right relation to each other, and in one way or another, to
manipulate all the organs which are actually employed in sustaining the
tones; but I found that as soon as a thought was held steadily in the
mind of the pupil, together with a dominating purpose to communicate
that thought to others in a way to affect their minds in a definite
manner the voice began to show evenness of support.