After supper she returned to her post, and, as she could not now see the glorious sky and the snowy fields, she let her attention fall upon the trains below that had begun to have a strange fascination for her. She had lost all fear of them by this time, and had even begun to notice that there were differences in them just as there were differences in people. Some were big and bulky, others were quick and dashing. Some had hoarse voices, some clear ones. The Canadian engines coming in shrieked in one tone, the American ones, passing them from the other direction, replied in another.