An Absent Minded ProfessorA notoriously absentminded professor was one day observed walking along the street with one foot continually in the gutter，the other on the pavement． A pupil meeting him said： “Good evening，professor．How are you？ “Well，” answered the professor，“I thought I was all right when I left home，but now I don't know what's the matter with me．I've been limping for the last half hour．”