THE FIRST MEN IN THE MOON
"We are some way in," he said. "I mean—perhaps a couple of thousand feet or more."
"Why?"
"It's cooler. And our voices are so much louder. That faded quality—it has altogether gone. And the feeling in one's ears and throat."
I had not noted that, but I did now.
"The air is denser. We must be some depth—a mile even we may be—inside the moon."
"We never thought of a world inside the moon."
"No."
"How could we?"
"We might have done. Only—one gets into habits of mind."
He thought for a time.
"Now," he said, "it seems such an obvious thing. Of course! The moon must be enormously cavernous with an atmosphere within, and at the centre of its caverns a sea. One knew that the moon had a lower specific gravity than the earth; one knew that it had little air or water outside; one knew, too, that it was sister planet to the earth and that it was unaccountable that it should be different in composition. The inference that it was hollowed out was as clear as day. And yet one never saw it as a fact. Kepler, of course—" His voice had the interest now of a man who has discovered a pretty sequence of reasoning.
"Yes," he said, "Kepler, with his subvolvani, was right after all."
"I wish you had taken the trouble to find that out before we came," I said.
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