THE SCIENCE OF MUSICAL SOUNDS
cially susceptible to this influence because its metal tube is
usually only 0.3 millimeter thick. It is conceivable that
the presence or absence of a ferrule or of a support for a key
might cause the appearance or disappearance of a partial
tone, or put a harmonic partial slightly out of tune.
The traditional influence of different metals on the flute
tone are consistent with the experimental results obtained
from the organ pipe. Brass and German silver are usually
hard, stiff, and thick, and have but little influence upon the
air column, and the tone is said to be hard and trumpet-
like. Silver is denser and softer, and adds to the mellowness
of the tone. The much greater softness and density of gold
adds still more to the soft massiveness of the walls, giving
an effect like the organ pipe surrounded with water. Elab¬
orate analyses of the tones from flutes of wood, glass, silver,
and gold prove that the tone from the gold flute is mellower
and richer, having a longer and louder series of partials, than
flutes of other materials.
Mere massiveness of the walls does not fulfill the desired
condition; a heavy tube, obtained from thick walls of
brass, has such increased rigidity as to produce an undesir¬
able result; the walls must be thin, soft, and flexible, and
must be made massive by increasing the density of the ma¬
terial. The gold flute tube and the organ pipe surrounded
with water, are, no doubt, similar to the long strings of the
pianoforte, which have a rich quality; these strings are
wound or loaded, making them massive, while the flexibility
or “softness” is unimpaired. The organ pipe partly
filled with water is like a string unequally loaded, its partials
are out of tune and produce a grotesque tone. A flute tube
having no tone holes or keys is influenced by the manner
of holding; certain overtones are sometimes difficult to
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