On the eclipses of agathocles, thales and xerxes

Abstract

The author, after remarking that the calculations of distant eclipses made in the last century possess little value, proceeds to give the successive steps of improvement in the lunar theory as applicable to the computation of eclipses, and especially in the motion of the moon’s node. The first great improvement was the introduction by Laplace of terms expressing a progressive change in the mean secular motions. With Bürg’s tables, in which these changes were introduced, or with the same elements, Mr. Francis Baily and Mr. Ottmanns computed many eclipses in the search for that usually called the eclipse of Thales; and both these astronomers fixed upon the eclipse of b. c. 610, September 30, as the only one which could be reconciled with the account of Herodotus.