merely expected that what had happened before, would happen again in similar circumstances. The case is, however, different in regard to the prediction of Sir Roderick Murchison, who foretold, simply from his knowledge of the laws of the distribution of gold on the earth's surface, that gold would be found in Australia. The discovery of new asteroids, is like the discovery of nuggets by the gold-digger. The starfinder, in such a case, claims none of the prophetic genius of Leverrier and Adams.
In September 1859, Leverrier, now director of the Observatory of Paris, laid before the Academy of Science the proofs which had led him to the conclusion, that there must be a planet within the orbit of Mercury. He shewed, in his paper, that the existence of such a planet would fully explain the apparent anomalies in the motion both of Mercury and the earth. He, at the same time, warned all observers to keep a sharp look-out upon the sun's disc, as the only hope of discovering it, was by detecting its transit. Being always in the immediate vicinity of the sun, and quenched by its rays, it could manifest its existence only by appearing as a black spot on the bright background of the sun. In December 1859, Leverrier received a letter, dated from the small town of Orgères, in the department of Eure-et-Loire. This was from M. Lescarbault, announcing that he had, on the 26th of March preceding, observed a small planet cross the disc of the sun. Leverrier lost no time in sifting the
