They dealt also with solar eclipses, and tried to trace on a sphere the path they would take on the earth. Accordingly, like the eclipses of the moon, these too were spoken of as happening either "according to calculation" or "contrary to calculation." "In a report sent in to one of the later kings of Assyria by the state astronomer, Abil Islar states that a watch had been kept on the 28th, 29th, and 30th of Sivan, or May, for an eclipse of the sun, which did not, however, take place after all. The shadow, it is clear, must have fallen outside the field of observation." Besides the more ordinary kind of solar eclipses, mention is made in the Observations of Bel of annular eclipses which, strangely enough, are seldom alluded to by classical writers. A record of a later eclipse has been found by Sir Henry Rawlinson on one of the Nineveh Tablets. This occurred near that city in B.C. 763, and from the character of the inscription it may be inferred that it was a rare occurrence with them, indeed that it was nearly, if not quite, a total eclipse. This has an especial interest as being the earliest that we have any approximate date for. It is possible that the remarkable phenomenon, alluded to by the prophet Isaiah, of the shadow going backwards ten degrees on the dial of Ahaz, may be really a record of an eclipse of the sun, such as astronomy proves to have occurred at Jerusalem in the year 689 B.C. We have very little notice of the calculation of eclipses by the Egyptians; all that is told us is more or less fabulous. Thus Diogenes Laertius says that they reckoned that during a period of 48,863 years, 373 eclipses of the sun and 832 eclipses of the moon had occurred, which is far fewer than the right number for so long a time, and which, of course, has no basis in fact. Among the Greeks, Anaxagoras was the first who entertained clear ideas about the nature of eclipses; and it was from him that Pericles learnt their harmlessness. Plutarch relates that Helicon of Cyzicus predicted an eclipse of the sun to Dionysius of Syracuse, and received as a reward a talent of silver. Livy records an eclipse of the sun as having taken place on the 11th of Quintilis, which corresponds to the 11th of July. It happened during the Appollinarian games, 190 B.C. The same author tells us of an eclipse of the moon that was predicted by one Gallus, a tribune of the second legion, on the eve of the battle of Pydna--a prediction which was duly fulfilled on the following night. The fact of its having been foretold quieted the superstitious fears of the soldiers, and gave them a very high opinion of Gallus. Other authors, among them Cicero, do not give so flattering a story, but state that Gallus's part consisted only in explaining the cause of the eclipse after it had happened. The date of this eclipse was the 3rd of September, 168 B.C.