45. Embolismic and common years
THE RECKONING OF TIME
general announcement might reach churches in far-o¡ lands.4 Indeed, in order to avoid exertion of this kind, the abovementioned man [Theophilus] composed a cycle now famous far and wide, which contains the fourteenth Moons of the ¢rst month in sequence, and permits anyone easily to ¢nd Easter Day, which will be on the very next Sunday.
Proterius, bishop of Alexandria, giving a most lucid explanation of this cycle at the request of the holy Pope Leo, was found worthy to be praised by him in the course of his reply: The letters of your well-beloved self, which our brother and fellow bishop Nestorius delivered out of pious courtesy, cause me joy. For it was ¢tting that such letters be sent to the Apostolic See from the bishop of the Alexandrian church, which [letters] would show what the Egyptians learned by the initial instruction of St Peter through his disciple St Mark, and which it is agreed the Romans believe.5 /420/
45. EMBOLISMIC AND COMMON YEARS
This same cycle is divided into common and embolismic years,6 which it is agreed are also observed by virtue of the authority of the ancient
Hebrews. It contains twelve common years, that is, [years] of 354 days, but seven embolismic years, that is, of 384 days. Now the ¢rst and second [years] are common, the third embolismic; the fourth and ¢fth are common, the sixth embolismic; the seventh is common, the eighth embolismic; the ninth and tenth common, the eleventh embolismic; the twelfth and thirteenth common, the fourteenth embolismic; the ¢fteenth and sixteenth common, the seventeenth embolismic; the eighteenth common, the nineteenth embolismic.
Both [years], as was said before,7 start from the beginning of the ¢rst month, which the Hebrews call Nisan; that is, it starts from the illumination of the Paschal Moon. The beginning of this month ought to be observed according to this rule: so that the fourteenth Moon of Easter never precedes the vernal equinox, but correctly appears either on the equinox itself (that is, on the 12th kalends of April [21 March]) or after it has passed. Hence it is that these beginnings of the lunar year are to be
4 St Leo the Great, Ep. 121 to Marcian (Krusch, Studien I, 258).
5 St Leo the Great, Ep. 129 (PL 121.1075A^B).
6 This chapter draws heavily on Dionysius Exiguus, Ep. ad Bonifacium et Bonum, passim.
7 See above, ch. 11.
TRANSLATION
looked for from the 8th ides of March [8 March] up to the nones of April [5 April]. Given that it falls on the 12th kalends of April [21 March] at the earliest and the 14th kalends of May [18 April] at the latest, /421/ this same fourteenth Moon makes us look for the day of the Paschal feast from the 11th kalends of April [22 March] up to the 7th kalends of May [25 April]. As Dionysius says: That calculation of the embolisms is demonstrably logical, which is seen to supply what is lacking to the common years so that the lunar course is equal to the solar period. For although the Moon traverses the annual circuit of the Sun every month, nonetheless it does not succeed in completing it in twelve months. For this reason the Moon is observed to fall short of the reckoning of the solar year by 11 days in common years; but in embolismic years, it is seen to overtake that same [solar] year by 19 days.8
Indeed the Hebrews, who recognized and observed in their law only lunar months of 30 or 29 days according to the natural course of the Moon,9 completed the 12 months in the common years, and in the second or third year, whenever it was appropriate, added a thirteenth embolismic month at the end of the year.10 Furthermore /422/ the Romans, who have months of unequal [length], do not wish to insert the embolisms into their calculation at positions chosen at random, but rather wherever in the midst of the year they could ¢nd a suitable empty interval between the kalends [of one month and the next].11 They said that the ¢rst embolismic Moon begins on the fourth nones of December
[2 December], the second on the fourth nones of September [2 September], the third on the day before the nones of March [6 March], the fourth on the day before the nones of December [4 December], the ¢fth on the fourth nones of November [2 November], the sixth on the 4th nones of August [2 August], and the seventh on the 3rd nones of March [5 March]. They shrewdly take every possible precaution so that whatever age the Moon might be on the kalends, that same Moon should be ascribed to the same month.12 However, this does not always
8 Dionysius Exiguus, Ep. ad Bonifacium et Bonum (83.10^16).
9 Bede's statement that the Hebrews alternated full and hollow lunar months is not accurate. Jones notes that such a statement is found in the recension of the Prologus
Theophili edited by Bouchier (472), to which Bede may have had access.
10 See above, chs. 11 and 13.
11 See Introduction, section 3.
12 ''Furthermore the Romans . . . ascribed to the same month.'' Cf. De ratione embolismorum, ed. by Jones amongst the alia opuscula coaeva in BOD 685^689.