can have no permanent, inherent energy of their own to generate or modify such energy of the sun, since they are in fact supplied by the solar energy, and their motions are controlled and regulated by the sun itself. Hence the inference is irresistible that the planets must derive their primary force from an external source not solar, and this they can only do by means of their rotation in space, and the only force derivable from space of which we have any knowledge is electricity, so that the circle thus becomes complete. How now shall we explain these periodical aberrations of energy? The color of a star, as we know, is no criterion of its age or size. The color is due to atmospheric absorption of the radiant light. The double stars, for example, revolve around each other at regular periods, and they are necessarily of nearly the same age, as sidereal ages are computed, but they frequently differ one from the other in color, and multiple stars may be all different each from the others; and the color, as before stated, is no criterion of size, for a small sun, with its glowing hydrogen in a state of high incandescence, and with few absorption bands in its spectrum, will appear bluish-white, or of that specific type of stars, without reference to size, while a much larger sun, with its light darkened by broad absorption bands and sun-spots, will appear orange or red; and, consequently, difference of color can be no criterion of distance, since a blue-white star of small size will outshine a red orb of much greater magnitude, whether it be more or less distant. The variable stars, for these reasons, belong to the order of red stars mostly, if not altogether. We must also bear in mind that sun-spots do not diminish the solar heat, as they are the result of increased and not of diminished energy. Electric currents of high potential pass directly, as we know, along the lines of least resistance to their opposite center of polarity, so that two planets nearly in conjunction with each other transmit their currents almost directly towards the sun's center, and upon the same point of solar latitude, while, if at right angles with the sun, they must deliver their electricity along converging lines and thus strike the solar surface at different points. Currents of electricity of high potential also (see "Electricity in the Service of Man," page 75), by their own passage, facilitate the passage of succeeding currents, so that generators discharging along the same lines find less and less resistance. It is true that we find no appreciable resistance in the passage of these currents between the earth and the sun, as their velocity is that of light, but both light and electricity may be equally retarded by resistance in a small degree. We know also that in the condensed hydrogen atmosphere of the sun there must be resistance, and also that the resistance in fluids diminishes as the temperature rises. Considering now the variable star Mira, as above