noticed it. But he showed no irritation, merely smiling, and saying, with
a wink at me and Henry:

"Even this seems to be rather too deep, so perhaps I had better show you,
instead of telling you, what I mean. Excuse me a moment."

He stepped out of the door, and we remained seated. We heard a noise
outside like the opening of a barn door, and immediately Edmund
reappeared and closed the door of the chamber in which we were. We
watched him with growing curiosity. With a singular smile he pressed a
knob on the wall, and instantly we felt that the chamber was rising in
the air. It rocked a little like a boat in wavy water. We were startled,
of course, but not alarmed.

"Hello!" exclaimed Jack. "What kind of a balloon is this?"

"It's something more than a balloon," was Edmund's reply, and as he spoke
he touched another knob, and we felt the car, as I must now call it, come
to rest. Then Edmund opened a shutter at one side, and we all sprang up
to look out. Below us we saw roofs and the tops of two trees standing at
the side of the street.

"We're about a hundred feet up," said Edmund quietly. "What do you think
of it now?"

"Wonderful! wonderful!" we exclaimed in a breath. And I continued:

"And do you say that it is inter-atomic energy that does this?"

"Nothing else in the world," returned Edmund.