Ventriloquism
2 of the 6 encyclopedias on this shelf carry an entry for Ventriloquism. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
the art of speaking in such a way as to cause a hearer to believe that the sound comes, not from the person speaking, but from a dif ferent source. The name originated from the erroneous supposition that the sounds uttered were formed in the belly, whereas practice alone is necessary to carry this act of illusion to a high degree of perfection. The sounds are formed by the ordinary vocal organs - the larynx, the Venus of the palate, the tongue, the lips, etc. The island of Milos art of the ventriloquist consists merely art she was draped, in later times nude. in this: After drawing a long breath he breathes it out slowly and gradually, dexterously modifying and diminishing, the sound of the voice; besides this he moves his lips as little as possible, and by various contrivances diverts the attention of his auditors. This art was known to the ancient Greeks.
Aiton's Encyclopedia (1910)
ven-tril'o-kwizm, the art of producing sounds in such a manner that they seem to come from some direction other than that of the speaker. A successful ventriloquist must also be able to imitate the voices and the noises of various animals. A ventriloquist in a crowded car, for instance, is able to create considerable sport by imitating the squeak of a mouse proceeding apparently from near a lady's feet, or the mew of a kitten which appears to proceed from someone's market basket. An imitative word of greeting, seeming to come from over one's shoulder where there is nothing but empty air, is sure to cause a stare of astonishment. The ventriloquist manages his voice by drawing in a deep breath and using the muscles of the larynx and the palate only, while the lips are held motionless so as to avoid detection.
What Has Changed in the Last Century
The technique described in 1921 and 1910 — deep breath, minimal lip movement, misdirection of the audience's attention — is still how it is done, and Collier's was right that the name's suggestion of speech formed "in the belly" is a mistake. What has been added is an explanation of why it works, which lies in the listener rather than the performer: experiments through the twentieth century showed that people localise sound poorly and that sight overrides hearing when the two disagree, an effect psychologists now literally call the "ventriloquist effect" and study as a case of audio-visual integration in the brain. The trade itself moved from the variety stage to broadcasting, most improbably on radio, where Edgar Bergen and his dummy Charlie McCarthy were a top American show from 1937 despite the audience being unable to see whether his lips moved at all. Aiton's cheerful advice about squeaking mice under a lady's feet in a crowded car has aged into something a modern reader would file under nuisance rather than sport.
Written for this edition, 2026.