Harry was red as fire during all these rapid questions, some apparently aimless, some sharply pointed.
"A man could not start that fire in Cazenove street at 3:30 and reach your house in Woodlawn at 3:45, could he?"
"Not very well."
"He might, however, start the fire at 3:28 and reach your house at 3:48?"
"I don't know," said Harry. "Twenty minutes isn't long."
"Isn't there a train which leaves the Southern depot at 3:29?"
"I never use the Southern depot."
"Never?"
"Well, not enough to know the trains."
"I have not said that you did, Mr. Arnold. It happens, however, that there was a train—an express train—which left the Southern depot at 3:29 on June 28, arriving in Woodlawn at 3:45. A person starting from Prof. Arnold's house at 3:28 could have caught that train, could he not?"