"Why, Don John, how you frightened me " exclaimed Miss Nellie Patterdale, as she sprang up from her reclining position in a lolling-chair. It was an intensely warm day near the close of June, and the young lady had chosen the coolest and shadiest place she could find on the piazza of her father's elegant mansion in Belfast. She was as pretty as she was bright and vivacious, and was a general favorite among the pupils of the High School, which she...