A well known writer on this subject has truly said: "* * * the limitations resemble those of a man using a telescope on the physical plane. The experimenter, for example, has a particular field of view which cannot be enlarged or altered; he is looking at his scene from a certain direction, and he cannot suddenly turn it all around and see how it looks from the other side. If he has sufficient psychic energy to spare, he may drop altogether the telescope that he is using, and manufacture an entirely new one for himself which will approach his objective somewhat differently; but, this is not a course at all likely to be adopted in practice. But it may be said, the mere fact that he is using Astral Sight ought to enable him to see it from all sides at once. And so it would, if he were using that sight in the normal way upon an object which was fairly near him--within his astral reach as it were; but at a distance of hundreds or thousands of miles the case is very different. Astral sight gives us the advantage of an additional dimension, but there is still such a thing as position in that dimension, and it is naturally a potent factor in limiting the use of the powers of its plane. * * * Astral sight, when it is cramped by being directed along what is practically a tube, is limited very much as physical sight would be under similar circumstances, though if possessed in perfection it will continue to show, even at that distance, the auras, and therefore all the emotions and most of the thoughts of the people under observation." The Astral Tube, in connection with Psychomancy, is used in a variety of forms. It is often used unconsciously, and springs into existence spontaneously, under the power of some strong emotion, desire or will. It is also observed in some cases of hypnotic phenomena, in which the hypnotist uses his will to cause his subject to form an Astral Tube, and then report his impressions. It is also used by the trained Psychomancer, without the use of any "starting point," or "focal centre," simply by the exercise of his trained, developed and concentrated will. But its most familiar and common use is in connection with some object serving as a "starting point," or "focal centre." The "starting point" or "focal centre," above mentioned, is generally either what is known as "the associated object" in the class of phenomena commonly known as "Psychometry," or else a glass or crystal-ball, or similar polished reflecting surface, in what is known as "Crystal Gazing." In the two next succeeding lessons, we shall consider these two forms of phenomena, respectively. LESSON V. PSYCHOMETRY.