THE DISCOVERY OF THE PLANET NEPTUNE.
In his solitary study sat a young man, pale and thoughtful. His eyes were fixed upon myriads of numerals, through whose complexity his far-reaching mind saw into the untold mysteries of the solar universe. His glass was not pointed to the heavens, his eyes looked not out upon the stars, but his soul, in deep abstraction, pondered over the perturbations of Uranus, as noted for many a year before by many a casual observer. He measured the intensity and the direction of the disturbing forces, questioned the planet that was seen and known concerning the unknown cause of its irregularities, and compelled a star, itself beyond the reach of the common eye, to tell of the whereabouts, the volume, the orbit, of its fellow, which no eye, even through an optic-glass, had ever yet seen, and whose very existence then came for the first time upon the mental vision of the youthful sage through the power of numerical calculation. His was a faith. It was the evidence of things not seen. But it was like that higher and better faith of which spake the great Apostle of the Gentiles,—fast and sure. Full of his discovery, Le Verrier offered his conclusions to the Academy; but learned men, when assembled in bodies, give to enthusiasts but a cold reception. Le Verrier, sure of his position, then wrote to Dr. Galle, the Astronomer-Royal in Berlin, asking him to point his powerful glass to a certain quarter of the heavens, where must be found at that time the last of the planets. And there it was; and thence it was traced upon its mighty way, bending, like its fellows, to the distant influence of its great centre, the sun. There is something almost affecting in the thought that Le Verrier should have been denied the first direct sight of the sublime star towards which his soul had been so long leaning and which had so long been within his mental vision. It was, however, a fortunate loss, since his adversaries would have charged him with having found by chance what he detected by reason, and thus have placed in a common category one of the most magnificent discoveries of modern times, a beautiful illustration of the gigantic power of calculation.
The distance of Neptune from the sun is 2,810,000,000 miles, and the time required for its orbital revolution, 164 years. Its diameter is 41,500 miles.