Tables of the Motion of the Moon

Abstract

THE appearance of Prof. E. W. Brown's lunar tables marks the accomplishment of an arduous task of the highest importance to astronomy. In the two centuries which have elapsed since the time of Newton more than a score of tables have been published. The majority of them naturally belong to the eighteenth century, and no longer possess any practical interest apart from the theories on which they, were based. If they did not always mark any very distinct advance in accuracy beyond their predecessors, they generally aimed at including a greater number of inequalities more precisely determined, and systematic observation of the moon was all the time accumulating the material which could be used for comparison with theory and the better determination of the fundamental constants. Newton himself discussed eight lunar inequalities. Euler in his memoir of 1772 included twenty-one inequalities each in the longitude and the radius vector and sixteen in the latitude. This was only a beginning. As time went on and the standard of achievement grew more exacting it is not surprising to find that the number of men who possessed both the ability and the patient energy to elaborate complete and independent theories of the moon's motion and to reduce them to the form of practical tables became notably smaller. Thus when Burckhardt's tables of 1812 had once been adopted in such annual publications as the Nautical Almanac, overcoming the rival claims first of Bürg and later of Damoiseauy they continued in use for the best part of half a century, although their deficiencies ultimately amounted almost to a scandal, and their form rendered it particularly difficult to reconstruct the underlying theory and to apply the needful corrections. A serious error in the parallax according to these takles was found and corrected by Adams.

Tables of the Motion of the Moon.

By Prof. Ernest W. Brown, with the assistance of Henry B. Hedrick. Sections i. and ii., pp. xiii + 140 + 39; section iii., pp. 223; sections iv., v., vi., pp. 99 + 56 + 102. (New Haven: Yale University Press; London: Humphrey Milford; Oxford University Press, 1919.) Price, 3 vols., 4 guineas net.