Sometimes these glimpses of the super-physical faculty come as waking visions, and sometimes they manifest during sleep as vivid or oft-repeated dreams. In this latter case the sight employed is perhaps usually of the kind assigned to our fourth subdivision of clairvoyance in space, for the sleeping man often travels in his astral body to some spot with which his affections or interests are closely connected, and simply watches what takes place there; in the former it seems probable that the second type of clairvoyance, by means of the astral current, is called into requisition. But in this case the current or tube is formed quite unconsciously, and is often the automatic result of a strong thought or emotion projected from one end or the other--either from the seer or the person who is seen. The simplest plan will be to give a few instances of the different kinds, and to intersperse among them such further explanations as may seem necessary. Mr. Stead has collected a large and varied assortment of recent and well-authenticated cases in his _Real Ghost Stories_, and I will select some of my examples from them, occasionally condensing slightly to save space. There are cases in which it is at once obvious to any Theosophical student that the exceptional instance of clairvoyance was specially brought about by one of the band whom we have called "Invisible Helpers" in order that aid might be rendered to some one in sore need. To this class, undoubtedly, belongs the story told by Captain Yonnt, of the Napa Valley in California, to Dr. Bushnell, who repeats it in his _Nature and the Supernatural_ (p. 14). "About six or seven years previous, in a mid-winter's night, he had a dream in which he saw what appeared to be a company of emigrants arrested by the snows of the mountains, and perishing rapidly by cold and hunger. He noted the very cast of the scenery, marked by a huge, perpendicular front of white rock cliff; he saw the men cutting off what appeared to be tree-tops rising out of deep gulfs of snow; he distinguished the very features of the persons and the look of their particular distress. "He awoke profoundly impressed by the distinctness and apparent reality of the dream. He at length fell asleep, and dreamed exactly the same dream over again. In the morning he could not expel it from his mind. Falling in shortly after with an old hunter comrade, he told his story, and was only the more deeply impressed by his recognizing without hesitation the scenery of the dream. This comrade came over the Sierra by the Carson Valley Pass, and declared that a spot in the Pass exactly answered his description.