Imprimatur; Atque imprimi forte necesse est, ut qui occasionem Schismatis hinc illinc quaerunt, se sciant nec hinc habere (nisi de ignorantiâ suâ aut malitiâ) quod querantur.  
Ex Aedib. Lambethan. April. 4. 1664. M. Frank S. T. P. R. in Christ. Pat. ac Dom. Archiepisc. Cantuar. à Sacris Dom.   

EASTER not Mistimed.  
A LETTER Written Out of the Country to a Friend IN LONDON Concerning EASTER-DAY.  
CR  
LONDON, Printed for Timothy Garthwait at the Kings-head in St. Paul's Churchyard, 1664.   

SIR,  
YOur Letter tells me, that you have met with very many men that say, We ought to keep Easter, this year, upon APRIL 3. though all our English Almanac-makers have placed it upon APRIL 10. Yet you cannot be of that opinion, because it seems unlikely that All our makers of Almanacs could be deceived in a thing of that nature, or that they would conspire to miss-lead the whole Nation, without any advantage to themselves. You therefore desire to know my mind concerning this Controversy, and that so fully and clearly expressed, as that it may enable you to escape undeceived by their seeming Reasons.  
To satisfy your desire; In the first place, I answer, that, In England, for this year 1664, Easter ought to be kept upon the tenth of April. And that, because no other day is designed by those old Rules which hitherto England hath always followed: and our Superiors have not yet substituted New Rules, commanding us to use them in the place of the Old ones. Witness the Book of Common-Prayer printed in Folio at London 1662.: Wherein the second Page, before the beginning of Morning-Prayer, hath A Table to find Easter for ever. Which Table had been often printed in the former Common-Prayer-Books; and by being reprinted, in the Edition of 1662., did sufficiently show that the Church of England had made no alteration for the time of celebrating Easter. That Table's title promiseth to show Easter for ever, only in opposition to the Table of Movable Feasts in the foregoing Page, which teacheth to find Easter for forty years only: so that after the year 1700, it will be almost useless. Yet that Table of forty years will always afford forty examples of Easter found by the following Table and by the Precept under it. If, for exercise, you seek all those forty Easters by the lesser Table, you shall find no other days than those that are set down in the greater Table, in the column whose title is Easter-day. The aforesaid Book of Common-Prayer hath two other old Touchstones, by which the forty years' Table may be tried; and (whatsoever others tell you) the forty Easters of that Table will endure all those three trials: and no difference will be found in them, if the Examiner have as much skill or sagacity, as that Book requireth in those that look after higher rules, and will not be content with the lowest and easiest sort of Precepts. The forty years' Table is fitted for mean understandings: But if men will question the truth of that Table, or the firmness of the grounds of its calculation, let them not blame that Book, because, for the satisfaction of their curiosity, it hath not other rules delivered in words solicitously weighed and considered, lest aught should be superfluous, deficient or ambiguous. If the High way be open, strait, plain, firm and safe; they that will run out of it, should not blame the Surveyors, if all the declivities and brinks of Rivers be not fenced with Guardefous.  
To come nearer to your Controversy. All the English Almanacs place Easter upon April the tenth, this year. The Book of Common-Prayer, in its forty years' Table, tells you that in 1664. Easter-day is April the tenth; yet some of your acquaintance say, We ought to keep it sooner. How much sooner? Ten days (say some, who know no difference between fixed and movable Feasts) France keeps Christmas ten days before us in England, therefore it keeps Easter so too. But if you meet with any such, tell them, That if the French keep Easter ten days before us, they must keep it on a Thursday. The difference of Old and New Style was introduced by skipping over ten days of the Month of October 1582; but keeping the names of the Weekdays unchanged. And therefore both Styles [calling the same day Sunday, and keeping Easter upon Sunday] must needs differ a just number of weeks, or not at all. Of the fourscore Easters kept since 1583, Weeks Easters. 0 36 1 26 4 5 5 13 Sum 80 36 differed not at all; 26 Roman Easters were a week before Ours, 5 were 4 weeks before ours, and 13 were 5 weeks before those that were observed in England: as shall be particularly shown hereafter, if need be. In all Roman-Catholick Countries, except Valesia, Easter-day will be kept upon their April 13., which we call Apr. 3, and so a week before us, this year 1664. But in the rest of Christendom, Holland and Zealand excepted, this year, the tenth of April will be observed for an Easter-day, even in the remotest parts of Asia and Africa. Because they, as well as we, find Easter-day by the Rules which were generally received by all Christians Eleven hundred and thirty two years ago, and were observed by all Christians ever since, till the year of our Lord 1583: when, in obedience to a Bull of Pope Gregory the Thirteenth, many Country's celebrated Easter, a fortnight sooner than the rest of Christendom. And ever since that year they have followed new Rules for the finding of Easter-day. Which Rules, 773 years hence, will give them an Easter-day six weeks before Ours: but, till then, none more than five weeks before us, as it was in 1663.  
But I need not speak any more of that Calendar, and its new Rules, at this time; although you tell me that divers Roman Catholics and Priests are eager pleaders for the third of April. I perceive that they pretend not to prove their Assertion, by saying It is so in the Roman Calendar; For they know, that Calendar is not yet publicly received in England. But they say It must be so; because in the Common-Prayer-Book printed 1662. there is this Rule, Easter-day is always the first Sunday after the first full Moon, which happens next after the one and twentieth day of March. But, say they, this year, that full Moon is on the one and thirtieth of March [a Thursday;] after which, the first Sunday is the third of April; the second Sunday is the tenth of April. Therefore, according to this Rule, not April the tenth, but April the third must be Easter-day. This were a sufficient demonstration, if the words full Moon had the same meaning in both places. But the FULL MOON meant in the Rule, this year, is no other than the fourth of April: Which being Monday, the first Sunday after it must needs be April 10, which, therefore, by this Rule, shall be Easter. If the Priests you writ of, make difficulty to admit such full Moons, pray them to search their Grandfather's Libraries, till they have found the Mass-book which was printed by Kingston and Sutton, in Quarto, at London, in 1555, which was the second year of Queen Mary. The Title of the Book is, Missale ad usum Ecclesiae Sarisburiensis. The Title of the second page is, Extracta ex compoto. (computo they would have said.) It contains no such Table of movable Feasts readily calculated, as our Liturgies are wont to have; but in stead of it, there are Rules for finding the Dominical Letters, the Leapyears, the Moveable-Feasts, the New Moons and Easter. Easter-day is there found by New or Full Moons, with these directions, 
Carmina docentia per novilunia invenire Pascha.  
Post regum festa, quaere novilunia trina  
Post dominica tertia, Pascha sacrum celebra.  
Aliud. Post veris Aequinoctium Quaere plenilunium:  
Et Dominica proxima sacrum celebra Pascha  
Non verius invenies, Si mille legas codices.   
The New Moon meant in those verses is not such as our Almanacs now profess to give us, namely the hour and minute of the true Conjunction of the Sun and Moon. But it is only the day of the Moons mean Conjunction, as it was above 1300 years ago; and is there found, merely by taking the day against which the proposed years Golden Number stands in the margin of each month. For that Computist knew well enough that that day would be four days after the New Moon of his own time; and therefore bids us begin at the day so found, and tell up wards a syllable to each day, saying In Coelis est hic; The syllable hic will fall four days above your Golden Number, and there show you the day of New Moon for your time.  
The full Moons meant in the same Verses are not so much as precise days of mean opposition of Sun and Moon, but are to be found in this plain manner. To the day of that ancient New Moon found by the Golden Number, add 13: So have you the 14th day of that Ecclesiastical Cyclic month; Which day Victorius (who flourished 1200 years ago) did call the Full Moon, and a great many others, after him, called it so.  
If you have not that Missale, you may try its rules in any other Book that hath the golden numbers set in the margin of each month, like that Missal; (as if 3 stand against the first of March, and 13 against the last of December.) Such were Henry the Eight's Bible printed 1540; Edward the Sixth's Common-prayer-Book, printed 1552; (for that of 1549 had no manner of direction to find movable Feasts) Orarium seu libellus precationum, published by Queen Elizabeth, 1560. I cannot tell you when the Golden numbers were first put up 4 days higher, to save men the labour of using In coelis est hic. I find them so high in the Common prayer Book printed at Edinburg 1637; as also in the great Church-Bible printed at London 1640. But in the Common prayer Book printed in folo 1662., those Golden numbers are restored to the places which they had in King Henry's Bible, King Edward's Liturgy, Queen Mary's Missal, and Queen Elizabeth's Orarium, except some few faults. But you will find no Rubric to tell you to what end they were set there. I will therefore here tell you some use of them.  
The Golden Number of any year, set to some day between March 7 and April 6, shows that day to be the Ecclesiastical beginning of that year. For when the Emperor Constantine had set an end to the cruel persecutions of the Christians, and had called that great Council of Bishops to Nicaea in Bythinia; They (abhorring those outrageous quarrels, and shameful disagreements which had been among Christians concerning the time of keeping Easter) did decree that thenceforth All Christians should, in remembrance of our Saviour's Resurrection, celebrate Easter upon the first Sunday after the fourteenth day of the first month: because the holy Scriptures bear witness, that our Lord did arise upon the first Sunday after the Jews Pass-over: And that their Pass-over Lamb was to be killed and eaten on the fourteenth day of the first month; which months were Lunar, and always began with the New Moons. The Astronomical spring, that is, the Vernal Aequinoctial, fell always before the middle of their first month Nisan. (For, the month, whose middle fell before the Vernal Equinox, they accounted the last month of the preceding year) But because this Decree would be ill observed, if all men were left to their little skill in the courses of the Sun and Moon, the Fathers of that Council referred the whole business to the Church of Alexandria; wherein at that time were more and better Astronomers, than in any other part of the world. Yet the rest of Christendom grew weary of depending upon Alexandria, and yearly expecting Letters from thence, to tell them when they were to begin their Lent, and to celebrate Easter. Which Letters often miscarrying, men grew impatient, and offered at several rules to enable men to find Easter day according to the Nicene Decree, without the help of Alexandria. But none had the hap to be generally liked, till one Dionysius Exiguus, in the time of the Emperor Justinian, fitted them with a Cycle of 532. years, which received universal approbation, and in short time, was every where received; and is in use in England at this day.  
The grounds of this Cycle are these. March 21. was then accounted the day of the Vernal Equinox. If this be the earliest fourteenth day of the month, then March 8. must be the earliest New Moon that can be admitted for a First month, or a beginner of the Ecclesiastical year. The next year First month will begin March 27. and so forth in this order, March. Ap. March. March. March. Ap. March Ap. March. March. 8. 27. 16. 4. 23. 12. 31. 20. 9 28. 17. 5. 25. 14. 2. 22. 11. 30. 19 and then March 8. again as at the first; The Moons returning after 19 years, as the Greeks had been taught long before they were Christians.  
I have not now time to tell you why these 19 several beginnings of the First month were not reckoned in this Order; for they accounted that year, the first of the Cycle, whose New Moon fell upon March 23. so that March the 8. gins the 16. year; and accordingly, in March and April, the New Edition of the Liturgy in Folio hath a Red 16. standing against March 8. and 17. against March 27. etc. Whence it is easy to draw such a Table as this, Golden Number. 16. 5. 13. 2. 10. 18. 7. 16. 4. 12. 1. 9 17. 6. 14. 3. 11. 19 8 First day Mar. 8. 9 11. 12. 14. 16. 17. 19 20. 22. 23. 25. 27. 28. 30. 31 Ap. 2. 4. 5 14. day Mar. 21. 22. 24. 25. 27. 29. 30. Ap. 1. 2. 4. 5. 7. 9 10. 12. 13 15. 17. 18 And thus we have found the 19 Easter limits. Terminus Paschalis, saith Scaliger, est quarta decima Luna mensis Paschalis Christiani seculo Constantini Magni. It is so called, because, as November 26. is always the limit for Advent, upon which day Advent Sunday never falls, but as soon after as may be; so every year hath a different limit for Easter, upon which limit Easter must not be kept, though it be Sunday; but on the first Sunday after the limit. As this year 1664. the Golden Number is 12. and therefore by the foregoing Table, this years Easter limit is April 4. which being Monday, the next Sunday after must needs be April 10. And that must be Easter day this year 1664. If you would seek it by the Table which teacheth to find Easter for ever, you must enter it with the Golden number 12. and the Sunday letter B (for the other letter C shows not Sunday after Mathias day) you will find April 10. as before.  
So that the Easter day of 1664. is found to be the tenth of April by all the four ways of finding, taught in the Common-Prayer-Book; namely, The Red numbers in the Calendar; The Rule next after the end of the Calendar; The Table for forty years; And the Table to find Easter for ever.  
If you doubt of the sense or truth of what I have here hastily written, let your next Letter tell me what it is you stick at, I shall endeavour to remove it, as being  
Sir Your, etc.