"They reached the station and spent a joyous two hours with the Porter. He was a worthy man and seemed never tired of answering the questions that begin with "Why--" which many people in higher ranks of life often seem weary of. He told them many things that they had not known before--as, for instance, that the things that hook carriages together are called couplings, and that the pipes like great serpents that hang over the couplings are meant to stop the train with."