William's explanation of his reasons was a most plausible one.
"The thing is this," said he. "As I am falling faster and faster every second, there is every instant a slight shock which tends to throw my blood upward."
He was, of course, referring to the well-known sensation that a man going down on a very rapid elevator experiences when the elevator starts, a peculiar disturbance in the pit of the stomach—the well-known sensation of falling. The reason is that the body of the man falls a small fraction of a second before his internal organs, and these consequently seem to rise up in his abdomen.
"Here in the car," continued our hero, "as my velocity increases every instant, I must feel the same kind of a shock continuously when I am upright in the air; but when, on the contrary, I turn head downward, the shocks will be in the direction of my feet, and will therefore tend to send the blood slowly away from my head. Besides, Dr. Giles recommended an upside-down position; and the farther I go, the more I see that he knew what he was about when he put up those signs on the walls."
It seemed as though William had hit upon the
