"My dear sir," I cried, "don't you see you've done thousands of pounds'
worth of damage?"

"There, I throw myself on your discretion. I'm not a practical man, of
course, but don't you think they will regard it as a cyclone?"

"But the explosion--"

"It was not an explosion. It's perfectly simple. Only, as I say, I'm apt
to overlook these little things. Its that zuzzoo business on a larger
scale. Inadvertently I made this substance of mine, this Cavorite, in a
thin, wide sheet...."

He paused. "You are quite clear that the stuff is opaque to gravitation,
that it cuts off things from gravitating towards each other?"

"Yes," said I. "Yes."

"Well, so soon as it reached a temperature of 60 degrees Fahrenheit,
and the process of its manufacture was complete, the air above it, the
portions of roof and ceiling and floor above it ceased to have weight.
I suppose you know--everybody knows nowadays--that, as a usual thing,
the air _has_ weight, that it presses on everything at the surface of the
earth, presses in all directions, with a pressure of fourteen and a half
pounds to the square inch?"

"I know that," said I. "Go on."

"I know that too," he remarked. "Only this shows you how useless