Occasionally, though rarely, the tube which is formed possesses another of the attributes of a telescope--that of magnifying the objects at which it is directed until they seem of life-size. Of course the objects must always be magnified to some extent, or they would be absolutely invisible, but usually the extent is determined by the size of the astral tube, and the whole thing is simply a tiny moving picture. In the few cases where the figures are seen as of life-size by this method, it is probable that an altogether new power is beginning to dawn; but when this happens, careful observation is needed in order to distinguish them from examples of our next class. 3. _By the projection of a thought-form._--The ability to use this method of clairvoyance implies a development somewhat more advanced than the last, since it necessitates a certain amount of control upon the mental plane. All students of Theosophy are aware that thought takes form, at any rate upon its own plane, and in the vast majority of cases upon the astral plane also; but it may not be quite so generally known that if a man thinks strongly of himself as present at any given place, the form assumed by that particular thought will be a likeness of the thinker himself, which will appear at the place in question. Essentially this form must be composed of the matter of the mental plane, but in very many cases it would draw round itself matter of the astral plane also, and so would approach much nearer to visibility. There are, in fact, many instances in which it has been seen by the person thought of--most probably by means of the unconscious mesmeric influence emanating from the original thinker. None of the consciousness of the thinker would, however, be included within this thought-form. When once sent out from him, it would normally be a quite separate entity--not indeed absolutely unconnected with its maker, but practically so as far as the possibility of receiving any impression through it is concerned. This third type of clairvoyance consists, then, in the power to retain so much connection with and so much hold over a newly-erected thought-form as will render it possible to receive impressions by means of it. Such impressions as were made upon the form would in this case be transmitted to the thinker--not along an astral telegraph line, as before, but by sympathetic vibration. In a perfect case of this kind of clairvoyance it is almost as though the seer projected a part of his consciousness into the thought-form, and used it as a kind of outpost, from which observation was possible. He sees almost as well as he would if he himself stood in the place of his thought-form.