The Astral Tube is formed by the person forming in his imagination (i.e., on the astral plane by means of his imagination or visualizing powers), a tube or small tunnel between himself and the person whom he wishes to influence. He starts by picturing it in his mind a whirling vortex, similar to the whirling ring of smoke emitted from a “coughing” engine, and sometimes by a man smoking a cigar, about six inches to one foot in diameter. He must will the imagined vortex-ring to move forward as if it were actually boring a tunnel through the atmosphere. When the knack of producing this astral tube is acquired, it will be found that the visualized tunnel seems to vibrate with a peculiar intensity, and will seem to be composed of a substance far more subtle than air. Then, at the other end of this astral tube you must picture the other person, the one whom you wish to influence. The person will seem as if viewed through the wrong end of an opera-glass. When this condition is gained, there will be found to be a high degree of en rapport between yourself and the other person. The secret consists in the fact that you have really established a form of clairvoyance between yourself and the person. When you have induced this condition, proceed with your mental commands and pictures just as if you were in the presence of the person himself. That is the whole thing in a nutshell.
In order that you may have another viewpoint from which to consider the astral tube, or what corresponds to it, I wish to give you here a little quotation from another writer on the subject, who presents the matter from a somewhat more technical standpoint. Read this quotation in connection with my own description of the astral tube, and you will form a pretty complete and clear idea of the phenomenon. The writer mentioned says: “It is impossible here to give an exhaustive disquisition on astral physics; all I need say is that it is possible to make in the astral substance a definite connecting-line that shall act as a telegraph wire to convey vibrations by means of which all that is going on at the other end of it may be seen. Such a line is established, be it understood, not by a direct projection through space of astral matter, but by such action upon a line (or rather many lines) of particles of that substance as will render them capable of forming a conductor for vibrations of the character required. This preliminary action can be set up in two ways—either by the transmission of energy from particle to particle, until the line is formed, or by the use of a force from a higher plane which is capable of acting upon the whole line simultaneously. Of course this latter method implies far greater development, since it involves the knowledge of (and the power to use) forces of a considerably higher level.