So now he provides the world with a series of maps of the human body; and he sits in front of his "subject," and his assistant places a specimen of blood in a little electrically connected box, and sets the rheostat at some vibration number-say fifty-and Dr. Abrams taps on a certain square inch of the abdomen of his "subject," and announces the dread word "cancer."
"The Book of Life: Vol. I Mind and Body; Vol. II Love and Society"
Upton Sinclair
A rheostat can be added to the motor circuit to regulate the speed.
"Hertzian Wave Wireless Telegraphy"
John Ambrose Fleming
He turned on the current from the small battery installed in it, then began talking at the same time he was turning a rheostat higher and higher.
"Man of Many Minds"
E. Everett Evans