In the year 1772 Bode of Berlin published the statement of a curiously symmetrical relation existing among the planets of our system. The gist of this relation, known as Bode's law, though it was really discovered by Titius of Wittenberg, may be summed up briefly thus: 'The interval between the orbits of any two planets is about twice as great as the inferior interval, and only half the superior one.' Thus the distance between the orbits of the earth and Venus should, according to Bode's law, be half of that between the earth and Mars, which again should be half of that which separates Mars from the planet next beyond him. Since the discovery of Neptune, this so-called law has broken down, for Neptune is very far within the distance which it requires; but at the time of its promulgation it represented with considerable accuracy the actual relative positions of the planets, with one exception. Between Mars and Jupiter there was a blank which should, according to the law, have been filled by a planet, but to all appearance was not. Noticing this blank in the sequence, Bode ventured to predict that a planet would be found to fill it; and his foresight was not long in being vindicated. Several continental astronomers formed a kind of planet-hunting society to look out for the missing orb; but their operations were anticipated by the discovery on January 1, 1801, of a small planet which occupied a place closely approximating to that indicated for the missing body by Bode's law. The news of this discovery, made by Piazzi of Palermo in the course of observations for his well-known catalogue of stars, did not reach Bode till March 20, and 'the delay just afforded time for the publication, by a young philosopher of Jena named Hegel, of a "Dissertation" showing, by the clearest light of reason, that the number of the planets could not exceed seven, and exposing the folly of certain devotees of induction who sought a new celestial body merely to fill a gap in a numerical series.'