"those fellows there have been swallowing your smoke, and glad to get
it."

He pointed at a row of what seemed to be grinning steel mouths, barred
with innumerable black teeth, and half concealed by a projecting ledge at
the bottom of the wall opposite the entrance, and as I looked I was
thrilled by the sight of faint curls of smoke disappearing within their
gaping jaws.

"They are omnivorous beasts," said Edmund. "They feed on the carbon from
your breath, too. Rather remarkable, isn't it, that every time you expel
the air from your lungs you help this car to go?"

None of us knew what to say; our astonishment was beyond speech. We began
to look askance at Edmund, with creeping sensations about the spine. A
formless, unacknowledged fear of him entered our souls. It never occurred
to us to doubt the truth of what he had said. We knew him too well for
that; and, then, were we not here, flying mysteriously through the air in
a heavy metallic car that had no apparent motive power? For my part,
instead of demanding any further explanations, I fell into a hazy reverie
on the marvel of it all; and Jack and Henry must have been seized the
same way, for not one of us spoke a word, or asked a question; while
Edmund, satisfied, perhaps, with the impression he had made, kept equally
quiet.

Thus another hour passed, and all of us, I think, had fallen into a doze,
when Edmund aroused us by saying:

"I'll have to keep the first watch, and all the others, too, this night."