The discovery of this planet is justly esteemed one of the greatest triumphs ever recorded in the annals of astronomy. The following is a brief résumé of the circumstances that led to it:— From a long and attentive course of observation on the planet Uranus, it was ascertained that it was subject to some disturbing agency, which frequently gave rise to a considerable discordance between the calculated and the observed path of the planet amongst the stars, and which could only be accounted for on the supposition that there was another, though as yet unseen, planet revolving round the Sun in an orbit exterior to that of Uranus. To discover the. suspected planet, MM. Adams and Le Verrier, the former in 1843, the latter in 1845, commenced independently, an examination of the theory of Uranus. From their investigations, they were both led to infer the existence of the unseen planet in the constellation Aquarius. M. Le Verrier having informed Dr. Galle, of the Royal Observatory, Berlin, of the result of his labours, that gentleman was fortunate enough to discover the planet on the night of Sept. 23, 1846, very near the position assigned by theory.