Chapter IX: Easter and the Moveable Commemorations

I. _Paschal Controversies prior to the Council of Nicaea._

The commemoration of the Pascha is the first annual Christian solemnity with which history makes us acquainted. And it will be well that the student should bear in mind that the term ‘Pascha’ was used in early times to signify, more particularly, not Easter (for which it was used in later times), but the day of the Lord’s Crucifixion, more commonly without, and sometimes together with, the succeeding two days, including the day of the Resurrection. But most commonly the word is employed in the earlier literature of the subject to signify the commemoration of the day of the Crucifixion, which was generally held to have corresponded in the history of the Passion to the day upon which the Paschal lamb was sacrificed in the Jewish ritual[140].

It is scarcely possible to conceive that, even if the Christian religion had taken its rise in circumstances altogether dissimilar from those amid which as a matter of history it actually emerged, there would have been no commemoration of such great events as the death and rising again of its Founder. But the first disciples of Christ being Hebrews, and their converts at first being also in a large measure Hebrews, it was inevitable that the great Hebrew festival of the Passover should take to itself a new colouring and a new significance in Christian thought. Thus we find St Paul speaking of Christ as ‘our Pascha’ (_i.e._ Paschal victim), which ‘hath been sacrificed for us’ (1 Cor. v. 7). And he adds, ‘therefore let us keep the feast (_or_ keep festival) not with the old leaven, neither with the leaven of malice and wickedness, but with the unleavened bread of sincerity and truth.’ It would indeed be unwarrantable to infer from this passage that a Christian Pascha was actually observed as a festival at the time when St Paul wrote to the Corinthians. But it is obvious that the passage is steeped in reminiscences of the Hebrew festival, and that these are already receiving a new complexion and a new meaning.

The observance of the Christian Pascha first comes into marked prominence about the middle of the second century. At that date it was everywhere a recognised institution of the Church; but there were differences between the Churches of proconsular Asia (the Asia of the seven Churches of the Apocalypse) and the Church at Rome and in other places, as to the particular day upon which the commemoration should be observed. The evidence with regard to the early stages of the dispute is scanty. Such details as we possess are not free from obscurity and have been variously interpreted.

In a work like the present volume we can do no more than lay before the student the results which seem to us to have the greater weight of probability in their favour.

The Asiatics, it would seem, began to celebrate the festival of the Pascha on the fourteenth day of the moon of the Hebrew month Nisan, the day upon which the Jews put away all leaven from their houses and slew the lamb of the Passover. On the whole, the evidence seems to make for the Asiatic Christians terminating the preceding fast on the evening of that day, and on the same evening celebrating the Paschal feast consisting of the Eucharist, accompanied, perhaps, by the Agape. It was on the fourteenth Nisan, according to the prevailing Asiatic belief, that the Lord suffered death upon the cross, and in His sacrifice became the true representative of the Paschal lamb which had been his antitype. Foreign as it must be to us with our habits of thought to conceive of a festival being kept on the day of the Crucifixion (that is, on the evening which was regarded as the beginning of the following day), we must suppose that the realisation of the blessings of the redemption purchased by the Saviour’s blood _overtoned_ (to borrow a term from the art of music) the imaginative presentment of the historical sufferings of the Cross. Our own English term, ‘Good Friday,’ seems to have originated with a similar way of regarding the facts[141].

From what has been said, it will be apparent that, as the fourteenth day of the moon might fall upon any day in the week, the commemoration of the Resurrection, three days later, might also fall upon any day of the week. At Rome, and in various other places, the festival of the Resurrection was always observed on a Sunday, because it was on the first day of the week that the Saviour rose from the dead. The Asiatics laid stress on the day of the _month_—the lunar month—on which the Saviour suffered: the Roman Church insisted that the sixth day of the _week_, Friday, was the proper day for commemorating the Crucifixion, and that the following Sunday should be kept as the feast of the Resurrection. Those who made the fourteenth day of the moon to be necessarily the day for the celebration of the Pascha were known as ‘Quartodecimans[142].’

The dispute was further complicated by the difference with regard to the observance of the fast. The Asiatics terminated their fast on the evening of the day of the Crucifixion. The Romans continued it till the morning of the day of the Resurrection.

The Asiatics claimed St John and St Philip, the Apostles, as the originators of the usage which they followed; and at the close of the second century they were able to recite a long list of holy bishops and martyrs who had never deviated from the practice of their Churches.

It was some time about the middle of the second century that St Polycarp, bishop of Smyrna, the personal disciple of St John, visited Rome, and conferred with Anicetus, the bishop of that city, on this and other subjects. On the Paschal question neither bishop was convinced by the other; but it was agreed that on such a matter it was not essential that there should be uniformity. The discussion was carried on with moderation, the two bishops received the Eucharist together, and Anicetus, ‘out of reverence’ for Polycarp permitted him to act as celebrant in his church[143].

The subject of the proper time for observing the Christian Pascha continued to excite discussion; and between A.D. 164 and 166, on the occasion of disputes at Laodicea, a defence of the practice of proconsular Asia came from the pen of one of the bishops of that region, Melito, bishop of Sardis. Unfortunately no remains of the work of Melito survive of such a kind as would help us to understand the writer’s argument, or to clear the difficulties which surround the attempt to form a well assured picture of the practice of his part of the Christian world. It has indeed been conjectured that the work of Melito was directed mainly against certain sectaries, perhaps Ebionites, who on the fourteenth day of Nisan feasted after the manner of the Jews upon a paschal lamb. This practice was so distinctly Judaistic, that it was rejected everywhere by the orthodox.

Of vastly more importance and significance, as affecting the whole Church, were incidents which occurred towards the close of the century. Victor, bishop of Rome, successor next but one to Anicetus, was a man of different temper; or, at all events, he attached a much higher importance to uniformity as to the time of observing Easter. Interest in the question was roused in various quarters. Councils of bishops (at the instance of Victor) discussed it in Gaul, in Greece, in Palestine, in Pontus, and as far east as Osrhoene beyond the Euphrates. By this time it was found that what, for convenience, we may style the Western practice was also largely followed in the East. The churches, however, of proconsular Asia still maintained their old position. A letter written by Polycrates, bishop of Ephesus, to Victor on their behalf is preserved by Eusebius[144].

Victor, departing from the moderate policy of his predecessor Anicetus, thought the time had come for dealing more drastically with his opponents on the Paschal question, and sought to cut them off from the communion of the Catholic Church[145]. Victor’s attitude called forth remonstrances from various quarters, and was the occasion of a remarkable letter written by Irenaeus, bishop of Lyons, in the name of the brethren in Gaul, over whom he presided. He declares that the mystery of the Lord’s Resurrection should indeed be celebrated only on a Sunday, yet he strongly urges the impropriety of Victor’s cutting off ‘whole Churches of God’ because of differences on such a matter. He then adds that the controversy was not only on the question as to the day on which Easter should be celebrated, but also on the length and manner of the preceding fast, varieties as to which he recounts (see p. 79); and he goes on to remind Victor that bishops of Rome in former times, while strictly preserving their own usages, did not break the peace of the Church by excommunications directed against those who followed other ways[146]. Letters of similar purport were addressed by Irenaeus to various other bishops. The result of this intervention was that the Asiatic Churches were for the time left undisturbed in the practice of their traditional usages. How soon the Asiatic Churches fell into line with the majority is not apparent. But it seems evident that the change had taken place before the Council of Nicaea.

We have seen that in the attempts to commemorate on the proper days the death and resurrection of the Lord, the Asiatics thought most of the _day of the month_, and the Westerns and those who concurred with them thought most of the _day of the week_. But the latter party had obviously to make some attempt to lay down a rule which would at least approximate the date of their Pascha to the time of the year when the Lord suffered. The vernal equinox was taken by them, and by the Church of Alexandria, as the fixed point to which the date of Easter should bear some settled relation.

It is perhaps impossible to determine with precision when the rule came to be generally accepted that the full moon, which was to regulate the date of Easter, was the first full moon _after_ the vernal equinox. We find that this is the rule which governs the Paschal Tables of Hippolytus (of which more will be said hereafter), and we find it expressly enjoined in that ancient collection of Church law which goes under the name of the Apostolic Canons. The Tables of Hippolytus can, with reasonable certainty, be assigned to A.D. 222. In the Apostolic Constitutions, the date of which it is impossible to determine with any close approach to certainty[147], the rule runs, ‘Observe the days of the Pascha with all care after the vernal equinox, that ye keep not the memorial of the one passion twice in a year. Keep it once only in a year for Him who died but once[148].’ The mystical reason assigned here also appears in the letter of the Emperor Constantine, announcing the decision to which the Nicene Council came upon the Paschal question[149]. Later on the reader will find what is probably meant by keeping the Pascha twice in the same year[150].

It would not perhaps be fitting to pass over in silence the attempt made in the early part of the third century by the Roman ecclesiastic, Hippolytus, to construct a cycle which would make it possible to predict the day on which Easter would fall in any future year.

As to who this Hippolytus was, Eusebius and subsequent students among the Fathers appear to have known scarcely anything. Eusebius speaks of the many writings of Hippolytus, and gives the titles of some of them, and describes one more particularly. This was a treatise _Concerning the Pascha_, in which was to be found a certain sixteen-year rule (canon) about the Pascha, the boundary of the writer’s computation being the first year of the Emperor Alexander[151], _i.e._ Alexander Severus, whose first year was A.D. 222.

The brief statement of Eusebius, dull and prosaic in itself, acquired suddenly a new and extraordinary interest in the year 1551, when during some excavations made in the neighbourhood of Rome, in the Via Tiburtina (the road to Tivoli), a much shattered statue was unearthed, which on being pieced together exhibited, on the sides of the chair in which the figure of a venerable looking man was represented as seated, two elaborate numerical tables, in Greek characters, one showing the day of the month on which the Pascha, or fourteenth day of the moon, would fall from A.D. 222 to A.D. 333: the other showing, for the same number of years, the day of the month upon which Easter ought to be kept. The statue, as restored, may now be seen in the Museum of the Vatican. The Tables are constructed in seven columns of sixteen years each. On the back of the chair were inscribed in Greek the titles of various books, many of which corresponded with the titles of works attributed to Hippolytus by Eusebius. There could be no reasonable doubt that the statue was the statue of Hippolytus, and that the Tables represented his calculations as to the time for keeping Easter.

A further confirmation of the correctness of this inference (though confirmation was indeed scarcely needed) emerged when a Syriac version of the Cycle of Hippolytus was discovered in a chronological treatise by Elias of Nisibis[152]. It corresponds exactly with the Tables inscribed on the chair.

An examination of the Tables of Hippolytus reveals that he assumed ‘that after eight years the full moons returned to the same day of the solar month; and he took notice that after sixteen years the days of the week moved one backward; that is to say, the full moon in the first year of the cycle being Saturday, April 13, after sixteen years it would be Friday, April 13, and so on[153].’ But for the purposes of what he supposed would be a perpetual Kalendar, Hippolytus desired to ascertain after what interval the full moon would fall not only on the same day of the solar month, but on the same day of the week. He assumed that this would happen after seven cycles of sixteen years.

We can also infer that Hippolytus probably placed the vernal equinox on March 18, for every full moon entered in his Tables is placed either on (as in the case of A.D. 235) or after that date.

Again, the examination of his Tables reveals what may seem to us the somewhat arbitrary regulation that if the full moon fell upon Saturday the Feast of the Resurrection should not be kept on the following day, but on Sunday a week later. The explanation probably is that it was considered that Easter should never be held earlier than the sixteenth day of the moon, that is, two days after the day of the Crucifixion. If the full moon fell upon Friday, then the following Sunday would be Easter; but if the full moon fell upon Saturday, the day of the Crucifixion was taken to be the following Friday, and Easter would be two days after.

No Easter cycle yet devised is free from errors, which have to be met by adjustments; but the Cycle of Hippolytus was such that the errors accumulated rapidly. It was more than two days wrong at the end of the first sixteen years; and five days wrong at the end of the second cycle; at the end of the third cycle it would be nine days wrong[154]. This must have been soon discovered; and the cycle had to be discarded. It is the earliest Easter cycle known to us.

A cycle on the same lines as that of Hippolytus, which has been (probably incorrectly) attributed to St Cyprian, will be found in Fell’s edition of Cyprian (1682), among the works commonly assigned to that writer. By whomsoever it was composed it is ushered in with a great flourish of trumpets, and the author feels sure that he has been led by nothing short of divine inspiration to the discovery. These Tables can be assigned to A.D. 243. One cannot but suspect that the author had got hold of the Hippolytean Tables before their worthlessness was discovered.

Such seem to have been the best efforts of the learning of Western Christendom in the third century to deal with the Paschal problem. Nor at this period was the Church of Alexandria, which at a later date became the paramount authority on such questions, any better equipped. Dionysius, about the middle of the third century, justly styled by Eusebius ‘the great bishop of Alexandria,’ made use of the eight-year cycle, which, like its variant, the sixteen-year cycle, gathered error rapidly.

It was, however, another distinguished Alexandrian, more than a quarter of a century later, who was the first, so far as we know, to make use of the old nineteen-year cycle for the determination of Easter. This was Anatolius, a native of Alexandria, and eminent for learning of various kinds (among which arithmetic, geometry, and astronomy are particularised), who became bishop of Laodicea in Syria Prima in A.D. 270. The nineteen-year cycle, with some modifications, eventually, though slowly, displaced all rivals[155].

II. _The Council of Nicaea and the Easter Controversy._

We may pass on now to the consideration of the determinations on this question arrived at by the Council of Nicaea.

The varieties of usage as to the dates of keeping the Pascha had disturbed the mind of Constantine before he issued his invitations to the bishops of the empire to attend the Council. His trusted adviser, Hosius, bishop of Corduba, had been sent by him to the East in the hopes that by his arguments and persuasion the followers of the Eastern practice might be induced to yield. But the mission was ineffective, and the matter was submitted to the great Council in A.D. 325. We have no record of any of the proceedings connected with the matter beyond what is to be found in a Synodical Letter of the Council, and a circular letter of the Emperor. We cannot help feeling some surprise that the Council did not enact any canon on the subject; but it was probably believed that the adoption of a rigid canon, with an attendant anathema, might have produced a formal schism, while a statement of the opinion of the Council could scarcely fail to be highly influential in eventually securing uniformity. The letter of the Council, preserved by Socrates[156], is addressed to the Church of Alexandria and the brethren in Egypt, Libya, and Pentapolis. It simply announces ‘the good news’ that, in accordance with the desire of those to whom the letter was addressed, the question had been elucidated by the Council, and that all the brethren of the East, who had formerly celebrated the Pascha ‘with the Jews,’ will henceforth keep it ‘at the same time as the Romans, and ourselves, and all those who from ancient times celebrated the day at the same time with us[157].’

The Emperor is more full. He says that it was thought by all that it would be fitting that the Pascha should be kept on one day by all; that it was declared to be particularly unworthy to follow the custom of the Jews who had soiled their hands with the most dreadful of crimes, and who are blinded with error, so that they even frequently celebrate two Paschas in one year. ‘Our Saviour has left us only one festal day of our deliverance, that is to say, of his holy passion; and he has willed that his Catholic Church should be one.’ How unseemly is it that some should be fasting while others are seated at the banquet! He hopes that every one will agree in this. It had been resolved that the Pascha should be kept everywhere on one and the same day[158].

There is nothing in these letters to show what rule had been established. All that is laid down is that the Pascha should be kept everywhere on the same day; and it assumed that the Roman and Alexandrian rules as to Easter were identical, and were well known. As a matter of fact, while the Churches of Rome and Alexandria were at one both in keeping Easter on a Sunday, and on a Sunday after the vernal equinox, they were not agreed in their methods of calculating the Sunday upon which Easter would fall. Hence, long after the Council of Nicaea, several instances occur in which a day was taken for the Easter festival at Rome which differed from the day which the Alexandrian experts had calculated to be the correct day.

It is worthy of observation that the Emperor in his letter reprobates what he assumes was the Jewish practice of frequently celebrating two Paschas in the same year. What is probably meant is that the Jews at that time (whatever their earlier practice may have been) did not think it necessary to keep the Passover _after_ the vernal equinox. Now the vernal equinox was taken as the beginning of the tropical or solar year; and it might happen from time to time that the full moon of Nisan fell in one year after the vernal equinox, and in the following civil year before the equinox, which would give two passovers in the same solar year. If this interpretation of the words of Constantine’s letter be correct, it would imply that the Christian Pascha should always be celebrated after the equinox, which was certainly already the general practice. But no specific rule with reference to the equinox is laid down in express terms either by the Fathers of the Council or by the Emperor.

It will be observed that in the Letter of Constantine he states that the Lord has left us ‘only one festal day of our deliverance, that is to say, of his holy passion.’ The dominant thought connected with the word Pascha was still that of the Crucifixion. At a later period writers, for the sake of accuracy, made the distinction between the ‘Pascha of the Crucifixion’ (πάσχα σταυρώσιμον) and the ‘Pascha of the Resurrection’ (πάσχα ἀναστάσιμον); and eventually the thought of the Crucifixion disappears from the connotation of the word, which has given the name for what we call Easter to the French (_pâques_); the Italians (_pasqua_); and the Spaniards (_pascua_)[159].

After the Council of Nicaea, although the Quartodeciman practice lingered on among unorthodox sectaries, the differences among Catholics were in the main confined to such questions as, When was the equinox? and What Tables should be used for predicting the Sunday which should be observed as Easter Day? The Synod of Antioch in A.D. 341 (can. 1) could now make bold to advance a step beyond the Oecumenical Council, and enacted a canon pronouncing excommunication against any who acted contrary to the command of the great and holy Synod assembled at Nicaea regarding the Pascha[160]. In principle the Church was united; but there were differences in the application of the principle. In A.D. 444, and eleven years later, in A.D. 455, Pope Leo the Great was in perplexity as to the day upon which Easter should be kept. In A.D. 444 he wrote to Cyril of Alexandria on the subject. The answer he received was that the proper day was not March 26 (as the Latins would make it) but April 23. In A.D. 455 Leo was much moved by finding that the Alexandrian computists had given April 24 for Easter Day, while those at Rome had assigned the festival to April 17, a week earlier. The matter seemed to him of sufficient importance to justify his writing to Marcianus, Emperor of the East, whom he now besought to intervene, and direct the Alexandrians not to name April 24, declaring that so late a date was beyond the ancient Paschal limits. Leo also wrote on the same subject to the learned and once beautiful Eudocia Augusta, who, though now spending her old age in retirement and devotion at Jerusalem, was not without influence in church affairs. The Emperor had enquiries made among certain bishops of the East and communicated with the Alexandrians. The result was that the observance of April 24 was reaffirmed, and the bishop of Rome reluctantly submitted for the sake of peace[161].

The account of the matter lies in the fact that while the Alexandrians had long before adopted the Paschal limits that still continue to rule our Easter, that is, from March 22 to April 25, the Latins, though at this date accepting the prior limit, hesitated as to the later, because the Easter Tables then in use among them had placed the later Paschal limit on April 23.

The position of authority conceded to the Church of Alexandria on the question as to the date of the Pascha was due to the acknowledged learning and skill of the astronomers and mathematicians of that city in matters of chronology and the computation of time. It was the practice of the bishop of Alexandria, as early at least as the middle of the third century, to issue what were styled ‘Festal Letters’ or, at a later date, ‘Paschal Letters,’ commonly of the nature of a homily on the religious lessons of the Paschal season, with an announcement as to the date of the next Pascha. These letters were commonly issued by the bishop a year in advance, and were sent by special messengers to his comprovincial bishops.

It has been supposed by several ecclesiastical historians of repute that the Council of Nicaea expressly authorised the bishop of Alexandria to issue these preparatory notices to the authorities in the various churches of Christendom. The evidence for this opinion is lacking; but certainly, as a matter of fact, the judgment of Alexandria carried great weight. In the West, however, the general practice was that Metropolitans should determine the date, and announce the day to their suffragans. In the sixth century the Council of Orleans (A.D. 541) directs that if the Metropolitan were in doubt he should consult the Apostolic see (Rome), and act in accordance with its decision (can. 1). About one hundred years later it would appear from the fifth canon of the Council of Toledo (A.D. 633) that the Spanish Metropolitan bishops did not receive information as to the date of Easter from any external source. They are directed to enquire among themselves by letter three months before the Epiphany, and make the announcement; and the reason assigned for this canon is that erroneous Easter Tables had caused differences.

To attempt anything like a detailed account of the varieties in the methods adopted for the determination of Easter which held their ground for a time, some in the East, some in the West, would be unsuitable in an introductory work like the present. The extraordinary persistence exhibited by the Celtic Churches of Britain and Ireland in maintaining for a long time their own method of computing Easter against the Roman method introduced by Augustine of Canterbury and his followers, is an important and interesting feature in the history of Christianity in these countries. It is enough here to say that the native Churches were not Quartodecimans (as has sometimes been incorrectly alleged), but were adhering to a cycle which they had received long before the Roman missionaries arrived in Britain[162]. We must here be content with briefly noticing some of the leading features in the history of the change which gradually led up to the adoption of the Nineteen-Year Cycle as modified and propounded by Dionysius Exiguus in the early part of the sixth century.

After the abandonment of the Cycle of Hippolytus there is found in use at Rome an 84-year cycle. In this the date of Easter is believed to have oscillated between March 25 and April 21; and between the fourteenth and twentieth day of the moon. This system, according to the results of recent research, was modified in A.D. 312 and again in A.D. 343. This cycle (still of 84 years) came to be known as the _supputatio Romana_. Easter could not now fall earlier than the sixteenth, nor later than the twenty-second of the moon, while its date limits were March 22 and April 21. This _supputatio_, with some modifications, served the bishops of Rome during the fourth and the greater part of the fifth century. The Alexandrians, on the other hand, had about A.D. 277 come to use the more exact Nineteen-Year cycle, with possible Easters between March 22 and April 25, and between the fifteenth and twenty-second of the moon[163].

In the pontificate of Leo the Great the differences which he had with the Church of Alexandria as to the date of Easter caused him to direct his archdeacon, Hilary (who afterwards succeeded to the papal throne), to investigate the whole question. Hilary resorted to the aid of Victorius of Aquitaine, who happened to be then at Rome. Victorius devised, or adopted, a cycle of 532 years, a combination of the lunar cycle of 19 years with the so-called solar cycle of 28 years (19 × 28 = 532). His Easter limits were March 22 and April 24.

The cycle of Victorius met with favourable acceptance, more particularly in Gaul, where it continued in use till nearly the end of the eighth century.

At Rome, whatever may have been the position actually attained by the cycle of Victorius, it and all other devices for determining Easter gave way in the sixth century (A.D. 527) before the Paschal Tables of Dionysius Exiguus. This remarkable person, who came to occupy an eminent place in the science of chronology generally, as well as in the computations necessary for ecclesiastical purposes, was a monk, a Scythian by birth, who settled in a monastery at Rome. It is to him that we owe in chronology the adoption by Western Christendom of what we know as the ‘Christian Era’ and ‘the year of our Lord,’ now in universal use for the dating of the events of history, and of all our documents public and private.

The system of Dionysius was, practically, the adoption of the Nineteen-Year Cycle of the Alexandrians. It fixed the date of the vernal equinox at March 21, placed the Paschal limits at March 22 and April 25, and declared Easter to be the next Sunday after the Paschal full moon. We have here in full the rule which eventually came to prevail everywhere. But its adoption was not immediate in all countries[164].

The space at our disposal will not allow of our treating in detail of the work of the computists, and of the ‘Sunday Letters,’ ‘Epacts,’ and other technical terms which appear in the old Church Kalendars. For these, as well as for such terms as ‘Indiction,’ ‘Lunar Regulars,’ ‘Solar Regulars,’ and ‘Concurrents,’ reference may be made to such books as Sir Harris Nicholas’ _Chronology of History_, and Giry’s fuller and lucid _Manuel de Diplomatique_.

_The Gregorian Reform._

The defects of the Nineteen-Year Cycle became apparent after some lapse of time. There were two grave sources of error. First, the Kalendar proceeded on the assumption that the solar year consisted of 365¼ days; but the true solar year is 11 minutes and some seconds shorter than the Kalendar year, and the accumulation of this error gradually brought confusion into the system. In one hundred and thirty years the Kalendar will have gained on the true solar year by almost exactly one day. At the date of the Council of Nicaea (A.D. 325) the vernal equinox was placed at March 21, but in the year A.D. 450 the true vernal equinox would be on March 20. In A.D. 585 the equinox would be on March 19; in A.D. 715 on March 18, and so on. And thus it will be seen that in A.D. 1582, when the Kalendar was reformed, the real vernal equinox was about ten days earlier than the March 21 of the Kalendar.

The second source of error lay in the assumption that at the close of a cycle of nineteen years there was an exact agreement of solar and lunar time. Nineteen solar years, of 365¼ days, make 6939 days and 18 hours; but 235 moons of 29 days, 12 hours, 44 minutes, and 3 seconds and a fraction make 6939 days, 16 hours, and a fraction over 31 minutes. So it comes about that the solar time in nineteen years is nearly 1½ hours in excess of the real lunar time. In other words, the moons in the second cycle of nineteen years make their changes nearly 1½ hours earlier than they did in the first cycle. It is easy then to show that in about 308 years this difference would amount to a whole day; and in A.D. 1582, when the Gregorian reform was effected, the moon in the heavens made its changes nearly four days before the time which was indicated for these changes in the Kalendar.

We must omit any notice of the various schemes for reforming the Kalendar prior to the reformation of Gregory XIII. After he had consented to the general idea that a reformation should be undertaken, various schemes were proposed. Of these, that of Luigi Lilio, a physician and astronomer of the city of Rome, obtained the preference[165]. And it is on the lines suggested by Lilio that the work was accomplished, mainly by a German mathematician then resident at Rome, the Jesuit, Christopher Schlüssel (or, in the Latin form of his name, Clavius), who afterwards published at Rome, in folio, an exposition of the work done, under the title _Romani Calendarii a Gregorio XIII Pontifice Maximo restituti Explicatio_ (1603).

LEADING FEATURES OF THE GREGORIAN REFORM

The Gregorian Reform is an ingenious and, indeed, brilliant practical solution of the problems presented by the condition of the Kalendar at the close of the sixteenth century. The characteristic features of the Gregorian system will now be described.

1. It was known that the true vernal equinox was at this date (1582) about ten days earlier than March 21 as marked in the Kalendar. Should the equinox be fixed as at March 11? It was resolved to keep the equinox at the nominal date of March 21, and to bring the date into conformity with facts by the simple process of striking out ten nominal days. It was decreed that the day following Oct. 4, 1582 (when what is known as the New Style was to make its beginning), should be counted, not as Oct. 5, but as Oct. 15. And thus in the following year, 1583, the true vernal equinox would fall on March 21, as it was supposed to have fallen in A.D. 325, the date of the Council of Nicaea.

2. But how was it to be provided that in the future the same errors which had vitiated the old Kalendar should not come in time to vitiate the new?

It will be remembered that the time of the old Kalendar had gained on true solar time at the rate, almost precisely, of one day in every 130 years. If the counting of one day could be suppressed in every 130 years, the end would be obtained. For purposes of practical convenience the reformers of the Kalendar assumed that 133 years should be taken as the period in which the Kalendar time exceeded the solar time by one day. The difference, for the purpose in hand, was insignificant; and, as will be seen hereafter, this deliberately chosen error will not affect the Kalendar to the extent of one day till A.D. 5200, while it makes calculations much simpler.

Now the plan adopted to prevent the accumulation of the error in the old Kalendar was as follows: if one day could be withdrawn in every 133 years, or, what is the same thing, three days in every 399 years, the object would be attained.

In the Old Style, every year of an exact century—every centurial (or, as it was sometimes called, secular) year—was a leap-year of 366 days. What would be the effect of treating every centurial year as a common year of 365 days? We should have suppressed four days at the end of four centuries when we ought to suppress only three in 399 years. So it was suggested that while three successive centurial years should be regarded as common years, the fourth centurial year should be treated as a leap-year. Thus, in both Old and New Style the years 1600 and 2000 are leap-years; but 1700, 1800, and 1900, which in the Old Style were leap-years, are in the New Style treated as common years of 365 days. And the rule laid down in the Gregorian system was that if the number expressed by the first two figures of the century was exactly divisible by 4 it should be a leap-year, but if not exactly divisible by 4 it should be treated as a common year. The numbers 16 and 20 are exactly divisible by 4, but 17, 18, and 19 are not so divisible. The years 1600 and 2000 are in the New Style leap-years, but the years 1700, 1800, and 1900 are in the New Style common years.

It is true that the adoption of 133 years, instead of 130 years, as the time in which in the Old Style one day was gained by the Kalendar on the sun, imports an error into the system, which causes the Kalendar to fall behind the sun. This error, as has been said, will accumulate to the extent of one day in A.D. 5200. It may be thought that, if men be on the earth at that date, they will know how to deal with the case. Yet it is suggested for the instruction of our remote posterity that they will have only to make A.D. 5200 a common year, instead of a leap-year, to bring things back to correctness[166].

For the Sunday letters in the New Style and for the Cycle of Epacts in the Gregorian Kalendar, see Dr Seabury, _Theory and Use of the Church Calendar_.

The work of the Gregorian reformation is marvellous in its elaborate ingenuity. It even provides for a case which will not occur till Dec. 31, A.D. 8600. Yet it does not reach the attainment of an exact correspondence with astronomical phenomena. And it has been frequently observed that the new moons of the Kalendar may occur one, two, or even three days _later_ than the new moons of the astronomer. In fact the astronomical new moon rarely occurs on the date marked for the ecclesiastical new moon. But care has been taken that the new moon of the Kalendar never occurs _earlier_ than the new moon of astronomy.

_The adoption of the New Style._

As was to be expected, the countries of Europe which recognised the authority of the bishop of Rome were not long in accepting the reformation of the Kalendar. Spain, Portugal, and part of Italy made the change on the same day as at Rome, that is on Oct. 15 (5), 1582. In France and Lorraine the change was made on December 20 (10) in the same year; in the Roman Catholic cantons of Switzerland in 1583 or 1584; in Poland in 1586; in Hungary in 1587. In Protestant countries and countries where Protestants were numerous the alteration was more slowly effected. But Denmark was an exception, for the New Style was adopted in 1582. In Holland and the Low Countries the provinces were divided in their acceptance of the New Style, and in some places the change was not effected till the year 1700. In Germany we also find a variety of usages: Austria and Roman Catholics in other parts accepted the change in 1584, but Protestants did not yield till 1700, when they adopted the Kalendar of the German astronomer, Erhard Weigel, which differed from the Gregorian Kalendar only in the rule for determining Easter. This variation brought about the result that the Protestants and Roman Catholics sometimes celebrated Easter on different days. In 1778 Frederick the Great ordained that from that time Easter should be kept at the time ascertained from the Gregorian Paschal moon. Weigel’s Kalendar was also adopted in the Protestant cantons of Switzerland in 1700. In Russia, Greece, and throughout the Christian East the Old Kalendar is still in use[167].

Great Britain was the last of the countries of Western Europe to adopt the New Style. It is true that as early as March 16, 1584-5, a bill was introduced in the House of Lords under the title, ‘An Act giving her Majesty [Queen Elizabeth] authority to alter and new make a Calendar according to the Calendar used in other countries.’ The bill was read a second time in the House of Lords, and proceeded no further.

Through an extraordinary blunder, it has been stated by writers of repute that Scotland adopted the New Style in A.D. 1600. The error originated in the fact that King James VI, with the advice of the Lords of his Privy Council, ordered by proclamation dated Haliruidhous, Dec. 17, 1599, that on and after Jan. 1, 1600, the year should be held to begin on Jan. 1 instead of March 25: but there was no rectification of the Kalendar by the omission of nominal days. In England the legal year continued to begin on March 25 till 1752. The accession of James VI to the throne of England on the death of Elizabeth occurred on March 24, 1602, according to the English style, but on March 24, 1603, according to the Scottish style. In this and such like cases the double dates may be wisely employed, thus, March 24, 1602-3. But Scotland did not use the New Style till it was adopted in 1752, in accordance with the provision of the Act of Parliament of Great Britain (24 George II, c. 23), entitled ‘An Act for regulating the commencement of the Year, and for correcting the Calendar now in use.’