The Railway Children - E. Nesbit

out.” She took his arm, and he let her.
“There's an awful lot of coal in the cellar, anyhow,” he went on.
“Oh, don't!” said Bobbie. “I don't think we ought to be glad about THAT.”
“I don't know,” said Peter, plucking up a spirit. “I'm not at all sure, even now,
that mining is a crime.”
But the girls were quite sure. And they were also quite sure that he was quite
sure, however little he cared to own it.