Page:Gods Glory in the Heavens.djvu/118

100, proclaims, in the most emphatic manner, the marvellous order of the heavenly host. An idea of the extreme accuracy with which the moon's position, at any moment, can be predicted, may be formed from the keen dispute at present (1860) going on in the Academy of Sciences between Leverrier and M. Delauny, in reference to the lunar theory of the latter, as compared with that of M. Hansen, the Danish astronomer, to whom is due the merit of discovering the difference of density between the nearer and more distant hemispheres of the moon. The controversy turns on the value of a constant entering into the calculation, and the difference between the two views is only a space, represented by the one three-hundredth part of the moon's apparent diameter. Yet on these few seconds of space, depends the result of an important question, on opposite sides of which the chief astronomers of our day are ranged. The Astronomical Society of London have virtually given their decision in favour of Hansen, by crowning him with their highest award of the gold medal. They have recognised his lunar tables as the complete solution of the grand nautical problem of finding the longitude at sea. The problem consisted in merely assigning, with absolute accuracy, the place of the moon in the heavens at any given time. Hitherto this was not done, as the perplexing and complicated irregularities of the moon's motion, baffled all attempts to calculate her position with the requisite accuracy. There are,