The following is from the file Saucer Song about Keely's demonstration
of an apparently acoustically TUNED motor. Once stimulated, it would
continue to run until suppressed by destructive interference.
"For his demonstration to Seaver, Keely stood at one end of his New
York laboratory; the motor was mounted at the other.
Then he played a certain note on a violin, whereupon the 25 h.p. motor
began to turn, gaining speed until it practically jumped its mountings.
It ran at this high speed during which time the inventor did nothing
more.
Eventually, to stop it, he again took the violin and played a discord,
whereupon the Force seemed to be withdrawn and the motor came to a
stop. "
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Another comment from the 1800s about tuned resonating spheres to
produce power and light as in the file AERO3;
"I pointed to the ship and expressed my wonder in my countenance. He
took me by the hand and led me toward it. In the side was a small
door. I looked in. There was a luxurious couch covered with robes of
the most beautiful stuff and texture such as I had never seen before.