Victor Mahillon, Kathleen Schlesinger, and Richard René Spiers, 1911 Encyclopædia Britannica (1911)
“ At the present day in England, France and America, the favourite mode of construction is that introduced by Theobald Boehm, and known as the “cylinder flute with the parabolic head,” of which more will be said further on. The successive opening of the holes and keys on the flute produces the chromatic scale of the first or fundamental octave. By increasing the pressure of the breath and slightly altering the position of the lips over the mouth-hole, the same fingering produces the notes of the fundamental octave in the next octave higher. ”
