416 TRANS. ST. LOUIS ACAD SCIENCE. 



extremely difficult to determine real transits of Venus before or 

 behind the sun's disk. Their only help was to observe, with the 

 naked eye, the latitude of Venus a short time prior to her con- 

 junction with the sun, and hence it came to pass that the ancients 

 sometimes took close conjunctions of Venus with the sun for 

 transits of the former. For the same reason the ancients deter- 

 mined very different periods of the reappearance of Phoenix. By 

 means of such ancient transits of Venus many epochs of Roman 

 history are incontrovertibly fixed. 



First, Pliny (H. N. xxx. 3 ; x. 2) narrates that the year u.c. 

 657, i.e. — 95, coss. Licinius and Cn. Cornelius, was the 215th 

 year of the Phoenix period. Consequently a transit of Venus 

 must have occurred in — 309 (954-214 = 309), coss. Bubulcus 

 Brutus III. and Aim. Barbula II. Pliny's authority is Manilius, 

 the notorious Roman astronomer. Indeed, in — 309, Nov. 22d, 

 the longitudes of the sUn and Venus were 7 s 26 , and that of the 

 U was likewise 7 s 26°. Accordingly Venus traversed in — 309 

 nearly the centre of the sun, but behind it, because the former 

 was in its superior conjunction with the sun. This astronomical 

 fact in u.c. 443 puts beyond the reach of controversy that Rome 

 was founded in — 752, and not, as Petavius made out, in — 753 ; 

 that the consuls Licinius and Cornelius as well as Brutus III. and 

 Barbula II. ruled one year later than formerly was believed. 



Further, in Tacitus (Ann. vi. 28) we read: "P. Fabio et L. 

 Vitellio coss. post longum saeculorum ambitum Phoenix in ./Egyp- 

 tum venit prasbuitque materiam doctissimis indigenarum et Grae- 

 corum, multa super eo miraculo disserendi." About that time 

 only one close conjunction of Venus with the sun was possible, 

 viz. a.d. 36, May 31, on which day the £1 of Venus lay 6° west 

 of the sun. During this conjunction the distance of Venus from 

 the sun amounted to 3S only. Consequently the said consuls 

 ruled one year later than Petavius stated. 



Aurelius Victor (Claud, iv. 12) : "hujus (Claudii) anno sexto," 

 says he, "DCCC. urbis, mire celebratus visusque apud - Egyptum 

 phoenix"; and Pliny (H. N. x. 2) reports: "Cn. Valerius phceni- 

 cem devolasse in yEgyptum tradidit, Q. Plautio, Sex. Papinio 

 coss. (a.d. 38) ; Allatus est in urbem, Claudii principis censura, 

 a. u. DCCC. ; et in Comitiis propositus, quod actis testatum est." 

 Suidas (v. 0oiv£) and Salinus (c. 36) narrate the same. About 



