NOTES. 



fonr appearances of comets fall in the long period of 32 Olympiads, viz. the 

 comet contemporaneous with the aerolitic fall, according to the Parian chroni- 

 cle, 01. 78, 1 (468 B.C.), under the Archoii Theagenides ; the great comet of 

 Asteus, which appeared at the time of the earthquake in Achaia, and disap- 

 peared in the constellation of Orion, in 01. 101, 4 (373 B.C.) ; the comet of 

 Eucles, the son of Molon, erroneously called Euclides by Diodorus (xii. 53), 

 in 01. 88, 2 (427 B.C.), as is also confirmed by the Commentary of Johannes 

 Philoponos ; and the comet of Nicomachus, in 01. 109, 4 (341 B.C.) In Pliny, 

 ii. 25, the 108th Olympiad is assigned to the jubse effigies rnutata in hastam. 

 Seneca also agrees in the immediate connection of the comet of Asteus (01. 

 101, 4) with the earthquake in Achaia, inasmuch as he mentions in the fol- 

 lowing manner the destruction of Bura and Helice, which towns are not 

 expressly named by Aristotle : " Effigiern ignis longi fuisse, Callisthenes tra- 

 dit, antequam Burin et Helicen mare absconderet. Aristoteles ait, non 

 trabem illam, sed cometam fuisse." (Seneca, Nat. Uusest. vii. 5.) Strabo 

 (viii. p. 384, Cas.) places the destruction of these two often mentioned 

 cities two years before the battle of Leuctra, whence we should again have 

 the date 01. 101, 4. Lastly, when Diodorus Siculus has described the 

 same event in more detail as taking place under the Archon Asteus (xv. 48 

 and 49), he places the bright "shadow- casting" comet (xv. 50) under the 

 Archon Alcisthenes, a year later, Ol. 102, 1 (372 B.C.), and makes it a herald 

 of the downfall of the Lacedaemonian dominion ; but Diodorus had the habit 

 of transferring an event from one year to another, and the more ancient and 

 secure authorities, Aristotle and the Parian Chronicle, testify in favour of the 

 epoch of Asteus in preference to that of Alcisthenes. Now as, by the assump- 

 tion of a period of revolution of 147| years for the fine comet of 1843, 

 Boguslawski traces it through 1695, 1548, 1401, and 1106, back to 371 years 

 before our era, we find it agree with the comet of the earthquake in Achaia, 

 according to Aristotle within two, and according to Diodorus even within one, 

 year, which, if we could know anything of the similarity of the orbits, would, 

 indeed, be a very small error considering the probable perturbations in so 

 long an interval. If Pingre, in his Cometographie, 1783, T. i. p. 259 262 

 (on the authority of Diodorus, and taking Alcisthenes instead of Asteus as 

 the name of the Archon), places the appearance of the comet in Orion of 

 which we are speaking in 01. 102, and yet calls the date July 371 instead of 

 372 B.C., it is no doubt because he agrees with some astronomers in marking 

 the first year before the Christian Era as anno 0. It must be remarked, in 

 conclusion, that Sir John Herschel takes for the bright comet of 1843 quite 



