448 TRANS. ST. LOUIS ACAD. SCIENCE. 



tude of the X3 was 3° 53' shorter, and the conjunction happened 

 2h. 30m. later, to the effect that a total, or nearly total, obscura- 

 tion of the sun took place at that time near Rome. The total 

 lunar eclipse took place on Jan. i8th, ()h. 30m., fi 0° W. Since 

 the phenomenon of two eclipses within fifteen days recurs only 

 after long intervals, the first year of Caesar's reign is fixed with 

 mathematical certainty. Petavius arbitrarily referred Caesar's 

 first year to — 50, but failed to produce two eclipses in January 

 of —50. 



^4) ^^- Ovid (Met. XV. 789) reports that about the day of Cae- 

 sar's assassination (Mar. 15) a total eclipse of the moon had taken 

 place (sparsi lunares sanguine currus) ; and Servius (ad Virgil. 

 Georg. i. 467) says, "Constat occiso Caesare solis fuisse defectum 

 ab hora sexta usque ad noctem." The sixth hour means, accord- 

 ing to the Julian day, sunrise, and the obscuration of the sun from 

 sunrise to sunset involves the opinion that on the occasion of solar 

 eclipses oin- globe is successively twelve hours under the shadow 

 of the moon. Virgil (Geor. i. 467) mentions only a solar eclipse 

 about the time of Caesar's death — "sol caput ferrugine texit"; and 

 the same we read in Ovid (Met. xv. 789) — " Lucifer ferrugine 

 textus erat"; and Tibullus (ii- 5? 75) — " solem defectum lumine 

 vidiL." Euseb. Chr. ii. 197, refers the same eclipse to Ol. 184, 

 3, consequently to the same year — 41, because he commenced 

 the Olympian years with the preceding local newyears day. Both 

 eclipses, it is true, were invisible in Rome ; but the said authors 

 intended only to commemorate the singular phenomenon, that, 

 about the time of Caesar's assassination, two eclipses occurred, 

 and that the Roman astronomers had, for a long time prior thereto 

 (p. 445), been able to determine in advance the times of eclipses. 

 The eclipses referred to are the following: J) — 41, March 13th, 

 ih.45m.p.m (P. T.), U 7° E., obscuration 8, 5 inches. ©—41, 

 March 27th, i ih. 45m. p.m., U 7° W. The former being partial, 

 was total, according to our Table (p. 429-30), because the ft lay 

 only about 3° 10' E. of the sun, which agrees with the ancient 

 reports. Since in the preceding year — 42 two eclipses within 

 fifteen days was impossible, these eclipses put it beyond question 

 that Cassair ruled 6 yrs. 3 mos., and not, as Petavius and his adhe- 

 rents believed, 5 yrs. 3 mos. ; that, moreover, Caesar died in —41, 

 and not, as stated in all our Chronological Tables, in — 43. This 



