The Talking Busts
Procure two busts of plaster of Paris; place them on pedestals, on the
opposite sides of the room. Let a thin tube, of an inch diameter, pass
from the ear of one head through the pedestal, under the floor, and go
up to the mouth of the other; taking care that the end of the tube
that is next the ear of the one head, be considerably larger than that
end which comes to the mouth of the other.
Now, when a person speaks quite low into the ear of one bust, the
sound is reverberated through the length of the tube, and will be
distinctly heard by any one placing his ear to the mouth of the other.
It is not necessary that the tube should come to the lips of the bust.
If there be two tubes, one going to the ear, and the other to the
mouth of each head, two persons may converse together, by whispers,
without the knowledge of any person who may stand in the middle of the
room.
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