You have heard of "Polarity," and "Polarization" in connection with electrical phenomena. "Polarity" is defined by Webster as: "That quality or condition of a body by virtue of which it exhibits opposite or contrasted properties or powers, in opposite or contrasted parts or directions; or, a condition giving rise to a contrast of properties corresponding to a contrast of positions." And, "Polarization" is defined by the same authority as: "Act of polarizing; state of having polarity." Well, then, the process of erecting the Astral Tube is practically that of the "polarization" of the particles of Astral matter by an effort of the human Will, set in motion by means of a strong Desire or Determination, under certain conditions.
When the human Will is directed toward a distant person or object, under the proper psychic conditions, it tends to "polarize" a path or channel through the Astral atmosphere toward the desired point, which channel becomes at once an easy course of psychic communication for the transmission or receiving of psychic impressions or expressions, as the case may be. And, in the case of Psychomancy and kindred phenomena, the Astral Senses of the person (even though his Astral Body be still within its physical counterpart) are able to readily "sense" the impressions being manifested at a far distant point in space.
The above mentioned channel of communication—the Astral Tube—has not of course the advantages of actual travel in the Astral Body, and is besides affected by certain Astral happenings, such as the breaking up of the tube, or an impairment of its efficiency, by reason of some stronger astral current or channel, etc., for instance. When one considers the currents and cross-currents constantly in operation on the Astral Plane, it will be seen how likely the above mentioned interference is to happen.
Through the Astral Tube the Astral Senses actually "sense" the sights, and often the sounds being manifested at a distance, just as one may see distant sights through a telescope, or hear distant sounds through a telephone, for instance. It also may be used as a microscope, as we shall see as we proceed. The student's attention is especially directed toward the fact that in this form of phenomena, the Psychomancer remains within his physical body, and does not travel in the Astral at all. He sees the distant scenes, just as a man sees them through a telescope. His consciousness remains within his physical body.
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. https://www.gutenberg.org/files/43954/43954-h/43954-h.htm