r. Our buildings are all subterranean. We avoid danger of
every kind. We dislike risk. You cannot see my house to which I am
taking you, but as a matter of fact it is less than a quarter of a mile
away."

He went so slowly that I had to abate my usual pace, lest I should
outstrip my guide. As he moved, he looked a little like a very small
tired elephant.

"Aviation," I said. "I suppose that with you that has been carried to a
great point of perfection."

"On the contrary," he said, "it is superseded. It is a back number. We
no longer use it. But we have seen no reason to change our style of
domicile, which possesses many advantages."

"And what is it?" I asked, "that has superseded aviation?"

"It is the power to dissipate and subsequently reconstruct identically
at some different point the atoms of any organism or group of
organisms."

"I don't think I understand," I said.

"It is natural that you should not. However, here we are at my house."

It looked to me rather as if we had come to an ordinary well, the
interior of which was occupied by a spiral descending incline.

"You will observe," he said, "that when I am weary of exertion and
return to my house, I descend. In the old type of house it was customary
to ascend."

I should calculate that we descended some thirty-five or forty feet
below the surface. At this point we were confronted by a perfectly
ordinary door with a brass knocker on it and an electric light above it.
On the door were painted the letters and figures MZ04. He opened the
door with a small latchkey, which he produced from one of his boots. The
keyhole and the handle were placed at such a height that it was easy for
him to reach them without assuming the erect position. We went through
into a small hall, brightly lit and containing no furniture but a
door-mat, on which my guide wiped his four boots carefully. He then
requested me to come with him into the dining-room, as indeed I was by
no means reluctant to do.

On entering this room, however, I was disappointed, for it bore no
resemblance whatever to a dining-room, and there was no look of good
cheer about it. Its walls were lined with shelves, and the shelves were
filled with numbered bottles containing what looked like small pills. In
the middle of the room, immediately under the light, was a low table, on
which were a row of small aluminium cups and a leather-bound book. There
was no other furniture of any description.

"You ar