"Thank you, David," said John. "I shall be glad to accept your offer. It's rather hot walking, and I shan't want to stop but a few minutes. Shall you go anywhere near the post-office?"
"Close by."
"I'll just run in there a minute."
"Have you got anything else to do?"
"No."
"You didn't set out to walk just to go to the Milbank post-office, did you?" asked David, in some surprise.
"I had a letter to mail."
"Couldn't you mail it at our post-office?"
"Yes, I could; but it wouldn't go."
"Why not?"