Bjerregrav sat there sunk in his own thoughts. Suddenly he looked up.

"Can you, who are so well read, tell me what keeps the moon from
falling? I lay overnight puzzling over it, so as I couldn't sleep.
She wanders and wanders through the sky, and you can see plainly
there's nothing but air under her."

"The devil may know," said Master Andres thoughtfully. "She must
have strength of her own, so that she holds herself up."

"I've thought that myself--for obligation isn't enough. Now we can
do that--we walk and walk where we are put down, but then we've the
earth under us to support us. And you are always studying, aren't
you? I suppose you have read nearly all the books in the world?"
Bjerregrav took the master's book and felt it thoroughly. "That's
a good book," he said, striking his knuckles against the cover and
holding the book to his ear; "good material, that. Is it a lying
story or a history book?"

"It's a travel book. They go up to the North Pole, and they get
frozen in, and they don't know if they'll ever get home alive
again."

"But that's terrible--that people should risk their lives so.
I've often thought about that--what it's like at the end of the
world--but to go and find out--no, I should never have had the
courage. Never to get home again!" Bjerregrav, with an afflicted
expression, looked first at one, then at another.