------------------------------------------------------------------------ [363] “Venus [ambitum epicycli peragit] anno Persico 1, mensibus 7, et diebus prope 9,” that is, the period of Venus on her epicycle is 365 + 210 + 9 = 584 days nearly, according to Alfraganus. The modern mean value is also 584 days. ------------------------------------------------------------------------ The period has been taken by some modern commentators to refer to the 225 days in which Venus revolves round the sun, but this period has no place in the Ptolemaic system. We cannot here discuss Dante’s allegory of the Gentle Lady and Philosophy, but in this passage he has stated without ambiguity or uncertainty the date of her first appearance.[364] ------------------------------------------------------------------------ [364] See Lubin’s _Dante e gli Astronomi Italiani_. The period of 225 days may be easily deduced from Ptolemy’s system, for it is the time in which the epicycle of Venus would make an absolute revolution round its centre, the diameter becoming parallel to its former position. But the Greeks invariably reckoned the period as the time in which it revolved relatively to Earth, that is 584 days. ------------------------------------------------------------------------ 6. ECLIPSES. We find solar eclipses mentioned six times in Dante’s works. As in all old records, there is no allusion to the features which chiefly strike modern astronomers—the pearly corona, and the blood-red prominences standing out like flames round the black disc. The terror of the sudden darkness, even when foreseen, seems to have absorbed all attention, and only the appearance of stars in the daytime and the frightened behaviour of animals was noted by Ristoro, and by others until quite modern times. In his letter to the Cardinals of Italy, Dante speaks of the shameful and grievous removal of the Papacy from Rome to Avignon as an eclipse of the sun.[365] In his dream of the death of Beatrice, he sees the sun so darkened that the stars appear, to his great terror:— ------------------------------------------------------------------------ [365] _Ep._ viii. 158, 159. “Poi mi parve vedere appoco appoco Turbar lo Sole ed apparir la stella.”[366] [366] “The while, little by little, as I thought, The sun ceased, and the stars began to gather.” _V. N._ xxiii. 176, 177. (_Rossetti_). See also the prose description just before, lines 35-37. ------------------------------------------------------------------------ He also refers to the disputed idea that the darkness at the time of the Crucifixion was caused by an eclipse of the sun,[367] and to the figurative eclipse which then took place in heaven.[368] ------------------------------------------------------------------------ [367] _Par._ xxix. 97-102. [368] _Par._ xxvii. 35, 36. ------------------------------------------------------------------------