midnight
`` Oh , well , we 'll get a chance at Pornell some day , '' answered Bert Field . The celebration along the lake-shore lasted until half-past eleven . Then the bell was rung , and laughing and singing , the cadets trooped off to their various dormitories . `` All quiet by midnight ! '' came the order . `` Fifteen minutes yet , '' cried Andy , consulting his watch . `` Whoop-la !