Sir Isaac Newton was first led to the subject of Astronomy by his thoroughness and scientific propensity. He studied Astrology, and proceeded to the study of Astronomy the better to understand and deal with the problems that the predictive science presented. For it is to be observed that Astrology in his day was entirely in the hands of astronomers, who calculated their own ephemerides and pursued the higher methods of astrological calculation as presented in my “Profnostic Astronomy.” Kepler avowed himself to be convinced of the truth of the science of Astrology, and showed himself to be a competent critic as much by his understanding of the astronomical problems involved as by his marvellous forecast of the rise and fall of Wallenstein. Tycho, his colleague and collaborator, also a great astronomical discoverer, was a professed Astrologer, and added to his stipend by the calculation of horoscopes. Astrology is quite a reputable study, and needs but to be emancipated from the service of a horde of half-educated plagiarists and parasites in order to take its place once more among subjects of serious consideration by the learned. Astronomy is interesting, but to be made useful it must find interpretation in terms of our daily life and common needs. It is in this connection that Astrology has played Cinderella since the days of official science. The day is not far off when it will come into its own. CHAPTER VII REVOLUTIONS, ECLIPSES, INGRESSES, ETC. Beyond the various time measures and indicators mentioned in Section IV, Chapter II, there are others which have a certain reputation among astrological students. The chief of these, and one that has been in vogue for many centuries, is the Solar Revolution, or Birthday Figure, as it is sometimes called. It consists in a map of the heavens for the return of the Sun to the exact zodiacal position that it held at birth, and this sidereal revolution is made the basis of an annual forecast of the general trend of affairs in the life of the subject. To find the time of the Sun’s return to its own place in the zodiac is, of course, a simple matter of proportion from the ephemeris for the current year. This is effected by comparing the radical or birthplace of the Sun with the longitude of the Sun in the Ephemeris on the anniversary day, which will give the increment more or less required to be equated. Then with this difference of the two positions of the Sun (a) at birth and (b) at noon of the anniversary, find the diurnal proportional logarithm and subtract from this the logarithm for the Sun’s motion in 24 hours. The result will be the logarithm for the hours and minutes from Noon at which the Sun was in the exact position it held at the birth. Thus you have the time of the solar return, and all that is necessary is to erect a horoscope for this time and set the planets in the figure.