404 TRANS. ST. LOUIS ACAD. SCIENCE. 



corresponding obscuration of the sun. Thus the very small eclipse of the 

 sun in — 420, Jan. 18, 2h., y 17 east of the sun, was invisible in Athens, 

 and vet the eve-witness Aristophanes saw it. Finally, many of the twenty- 

 nine total solar eclipses mentioned in the classics were, according to our 

 Lunar Tables, annular ones; and by means of them the usual secular 

 acceleration of the Apsides can be corrected. To this class, e.g. the eclipses 

 in — 5S1, Mar. 27 ; —400, July 1 ; —360, May 12 ; —306, June 13. belong. 



Since, then, the classic eclipses are very important in establishing a 

 correct theory of the moon's motions, the next task must be. first, to col- 

 lect, at least to a.d. 400, all reports of the classic authors referring to an 

 eclipse either of the sun or the moon, and specifying the localities, and 

 magnitudes, and hours of the respective eclipses; in the second place, to 

 reduce the latter to their real years. The chronology of ancient eclipses 

 is inseparably connected with the historical Chronology of the Romans, 

 Greeks, Babylonians, Egyptians, Chinese; and, in this respect, history 

 has made considerable progress since Ptolemy, especially since Peta- 

 vius, whose chronology is notoriously based upon Ptolemy's erroneous 

 Historical Canon. 



New Astronomical and Historical Subsidiaries of Ancient Chronology 

 and History. 



Since the year 1627, in which Petavius's Doctrina Temporum. 

 the hasis of all later Chronological Tables down to Clinton and 

 Fischer, made its appearance, a great many of both astronomical 

 and historical materials have come to light, by which all events 

 of Roman, Greek, Babylonian, Egyptian, Hebrew, and other his- 

 tories, especially the dates of ancient eclipses, are incontrovertiblv 

 fixed, as will be seen in the author's "Astronbmia .Egyptiaca." 

 1S33 ; in his "Chronology of the Roman Emperors" (Gettysburg 

 Quarterly Review, 1S72, p. 47), and the other aforecited works 

 (p. 403). It will be sufficient to specify only, and as briefly as 

 possible, the following : 



1. Planetary Configurations, Lectisternia, Pulviiiaria, 

 '/spat xAcvat, that is to say. representations of the ancient seven 

 planets — Saturn, Jupiter, Mars, Sun, Venus, Mercury, and Moon 

 — together with the Signs and smaller parts of the Zodiac with 

 which the former were conjoined on certain days of certain years. 

 Nearly all these autoptical observations were performed on the 

 cardinal day preceding the historical event which they referred 

 to. These planetary configurations are the most solid fundamen- 

 tals of ancient chronology, because none of them returns twice 



