"The German trains rarely go more than four miles an hour."
"Why, that's no faster than a smart boy can walk."
"Rather, I think."
"You are joking, doctor."
"I never was more serious in my life. This train is not going more than four miles an hour."
"I should say it was going at the rate of twenty."
"I am afraid you have not read your guide-book since you came into Germany," laughed the doctor. "Perhaps it has not occurred to you that a German mile is equal to about four and two thirds English miles."
"I didn't think of that."
"It is sixty-four and a half English miles from the point where we started to Ulm; and the time is over three hours. We shall arrive there at half past five," continued Dr. Winstock.
"I thank you for setting me right," replied Paul. "I have been bothered with the German money."