the different Sundays and festivals ordained by the Church to be kept holy. Some religious festivals-such as the Feast of S. Andrew, the Nativity of our LORD, the Annunciation of the Blessed Virgin, &c.-are observed on the same day of the month every year; others, such as Easter, return on different days in different years, whence they are termed Moveable Festivals. Easter is the most important of all, for upon this depend nearly all the

rest.

The Jewish Feast of the Passover was observed in accordance with the following commands:-" In the 1st month, on the 14th day of the month at even, ye shall eat unleavened bread, until the 21st day of the month at even." (Exodus, xii. 18.) Again :"In the 14th day of the 1st month at even, is the LORD'S Passover." (Leviticus, xxiii. 5.) And since our SAVIOUR was crucified at the time of the Jewish Passover, our festival of Easter has ever been a moveable one. The word is probably of Saxon origin, for the ancient Saxons sacrificed in the month of April to a goddess whom they called Eoster (in Greek Astarte, and in Hebrew Ashtaroth h), whose name was given to the month in question. It has been suggested that the word East in Saxon refers to "rising," and that the point of the compass now known by that name derived it from the rising of the Sun, and the festival from the rising of our SAVIOUR. Another derivation is the Saxon yst, a storm, on account of the tempestuous weather which frequently prevailed at this season of the year. That the observance of Easter as a Christian institution is as ancient as the times of the holy Apostles there can be no doubt; but in the 2nd century a controversy arose as to the exact time at which it ought to be celebrated. The Eastern Church elected to keep it on the 14th day of the 1st Jewish month; and the Western on the night which preceded the anniversary of our SAVIOUR'S Resurrection. The objection to the former plan was, that the festival was commonly held on some other day than the 1st day of the week, which was undoubtedly the proper one. The disputing branches of

h Vide Milton, Paradise Lost, b. 1. 1. 438, where it is referred to as a Phoenician deity.

the Catholic Church each had their own way until 325 A.D., when the Council of Nicæa ordered that it should be kept on the Sunday which falls next after the first Full Moon following the 21st of March, the vernal equinox. If a Full Moon fall on the 21st of March, then the next Full Moon is the Paschal Moon; and if the Paschal Moon fall on a Sunday, then the next Sunday is Easter Day.

By common consent, it is not the apparent or real Sun and Moon which is employed in finding Easter, but the mean or fictitious sun and moon of astronomers. We must, therefore, not be surprised at finding sometimes the Easter of any year not agreeing with the above definition. Such was the case in 1845 and in 1818, when violent controversies took place about it. Suppose, for instance, that the real opposition of the Sun and Moon took place at 11h 59m P.M., March 21, and the mean opposition 2m afterwards. It is clear that, counting by the real bodies, the Full Moon in question would not be the Paschal Moon, while that of the mean bodies would be so. However, the following rules will determine the Easter Day of chronologists for any year of the Christian era, and this is all that is necessary:-—

I. Add I to the given year.

II. Take the quotient of the given year, divided by 4, neglecting the remainder.
III. Take 16 from the centurial figure of the given year if it can be done.
IV. Take the remainder of III, divided by 4, neglecting the remainder.

V. From the sum of I, II, and IV, subtract III.

VI. Find the remainder of V, divided by 7.

VII. Subtract VI from 7: this is the number of the DOMINICAL LETTER.

VIII. Divide I by 19: the remainder (or 19 if there is no remainder) is the GOLDEN NUMBER.

IX. From the centurial figures of the year subtract 17, divide by 25, and keep the

quotient.

X. Subtract IX and 15 from the centurial figures, divide by 3, and keep the

quotient.

XI. To VIII add 10 times the next less number, divide by 30, and keep the

remainder.

The investigation of this question is too long and complicated to interest the general reader. Those who wish for it will find it in a valuable memoir, by Prof.

De Morgan, in the Companion to the
Almanac for 1845, p. 1 et seq.

* Gauss's method is a very good

one.

XII. To XI add X and IV, and take away III, throwing out the thirties, if any. If this gives 24, change it into 25. If 25, change it into 26, whenever the Golden Number exceeds II. If o, change it into 30. Thus we get the EPACT.

When the Epact is 23 or less.

XIII. Subtract XII from 45.

XIV. Subtract the Epact from 27, divide by 7, and keep the remainder.

When the Epact is greater than 23. XIII. Subtract XII from 75.

XIV. Subtract the Epact from 57, divide by 7, and keep the remainder.

XV. To XIII add VII (and 7 besides, if XIV be greater than VII) and subtract XIV, the result is the day of March, or, if more than 31, subtract 31, and the result is the day of April on which Easter Day falls.

XV. 42+1+7-3=47; subtract 31, and we get April 16 as Easter Day.

Easter Day being known, any of the other days depending

on it can readily be found.

Septuagesima Sunday is 9 weeks

Sexagesima Sunday is 8 weeks

Shrove or Quinquagesima Sunday is 7 weeks

Shrove Tuesday and Ash Wednesday follow Quinquagesima Sunday
Quadragesima Sunday is 6 weeks

Palm Sunday is 1 week

Good Friday is 2 days

Low Sunday is I week

Rogation Sunday is 5 weeks

Ascension Day, or Holy Thursday, follows Rogation Sunday

Whitsun-Day is 7 weeks

Trinity Sunday is 8 weeks

Before Easter.

After Easter.

1

CHAPTER IV.

The Dominical or Sunday Letter.-Method of finding it.-Its use.-The Lunar or Metonic Cycle.-The Golden Number.-The Epact.-The Solar Cycle.-The Indiction. The Dionysian period.-The Julian period.

THE

HE Dominical Letter, called also the Sunday Letter, is an expedient by means of which we can readily find out the day of the week on which any day of the year falls, knowing the day of the week on which New Year's Day falls. To the first 7 days of January are affixed the first 7 letters of the alphabet―A, B, C, D, E, F, G; and of these, that which denotes Sunday is the Dominical Letter. Thus, if Sunday is New Year's Day, then A is the Dominical Letter; if Monday, that letter is G; and so on. If there were 364 days, or 52 weeks, exactly in the year, then the Dominical Letter would always be the same; but as the year contains about 365 days, or 11 more than 364, this excess has to be taken into account every year, and the makes a day in every 4 years; so that the Dominical Letter falls backward one letter every common year, and two letters every Bissextile or Leap year. Knowing the Dominical Letter, we can ascertain all the Sundays, all the Mondays, &c., in the year. The reason why Leap years have 2 letters may be thus explained :-Take, for example, the year 1860. The year begins on a Sunday, so A is the Sunday Letter; but the intercalary day, February 29, throws back the 1st of March a day later than it would otherwise have been, and therefore the Sunday Letter for the following 10 months is thrown back that is to say, to G; so that the Dominical Letters for 1860 are A and G. The following examples, worked according to