In the same way, the telepathic waves of energy are sent forth by the activity released by the thought or emotion state. These waves travel in every direction, and when they come in contact with physical apparatus sufficiently sensitive to register them, they may be reproduced or retransformed into thought or mental states similar to those which originally sent them forth. You talk into the receiver of the telephone, and the sound waves are transformed into waves of electricity. These electric waves travel over the wires, and on reaching the other end of the telephone circuit are again transformed into sound-waves which are heard by the ear of the listener. Well, then, when your brain sends out thought waves, these travel until they are received by the apparatus in the brain of another person, when they are re-transformed into thoughts of the same kind that originally caused the thought-waves. I will have much more to say on this subject in the next chapter. I will pause here to point out the difference between the phenomena of this form of telepathy, and the higher form which is really a phase of clairvoyance. Now, in the case of what may be called a clairvoyant-telepathy, or astral telepathy, the ordinary thought-waves play but a small part. Instead of these, there is a transmission of force along the channels of the astral plane. It is almost impossible to describe the phenomena of the astral plane in the terms of the physical. I may illustrate the matter, in a general way, by saying that is something like your astral self actually extending itself out until it touches the astral self of the other person, and thus actually "feels" the astral activities there, instead of it being a case of something like waves travelling along space between brain and brain. Do you get this clearly? This is about as near to it as I can explain it to you at this place. Telepathy is simply a matter of the transmission and receiving of waves of vibratory force which have travelled along the ether between two persons. But clairvoyance or astral-telepathy is something like your mind being extended out until it actually touches the mind of the other person and sees what is there. I shall have much to say regarding the working out of the processes of clairvoyance, as we proceed. I have merely given the above explanation for the purpose of distinguishing between ordinary telepathy and clairvoyance, so as to prevent you from falling into a common error. Now let us consider the phenomena of ordinary telepathy--this is very wonderful in itself, although it is on a lower plane of activity than its astral or clairvoyant counterpart. LESSON III. TELEPATHY EXPLAINED.