Page:Encyclopædia Britannica, first edition - Volume I, A-B.pdf/592

 ,,92 ASTRO to be placed one day earlier in the kalendar for the next gio years to come. Thefe numbers were rightly placed againft the days of new moon in the kalendar, by the council of Nice, A. D. 325 ; but the anticipation, which has been neglefted ever fince, is now grown almoft into 5 days: And therefore, all the golden numbers ought now to be placed 5 days higher in the kalendar for the old ftyle than they were at the time of the faid council; or 6 days lower for the new ftyle, becaufe at prefent it differs 11 days from the old.

In the above table the golden numbers under the months ftan^l againft the days of new moon in the lefthand column, for the new ftyle ; adapted chiefly to the fecond year after leap-year, as being the neareft mean for all the four; and will ferve till the year 1960.- Therefore, to find the day of new moon in any month of a given year tiU that time, Jook for the golden number of

N O M Y. that year under the defired month, and againft it you have the day of new moon in the left-hand column. Thus, fuppofe it were required to find the day of new moon in September ,1769 ; the golden number for that year is 3, which I look for under September, and right againft it in the left-hand column you will find 30, which is the day of new moon in that month. N. B. If all the golden numbers, except 17 and 6, were fet one day lower in the table, it would ferve from the beginning of the year 1900 till the end of the year 2199. The table at the end of this chapter (hews the golden number for 4000 years after the birth of Chrift, by looking for the even hundreds of any given year at the left hand,, and for the reft to make up that year at the head of the table ; and where the Columns meet, you have the golden number (which is the fame both in old and new ftyle) for the given year. Thus, fuppofe the golden number was‘wanted for the year 1769; look for 1700 at the left hand of the table, and for 69 at the top of it; then guiding your eye downward from 69 to over-againft 1700, you will find 3, which is the golden number for that year. But becaufe the lunar cycle of 19 years fometimes includes five leap-years, and at other times only four, this table will'fometimes vary a day from the truth in leapyears after February. And it is impoflible to have one more correct, unlefs we extend it to four times 19 or'7 6 years ; in which there are 19 leap-years without a remainder. But even then to have it of perpetual ufe, itmuft be adapted to the old ftyle; becaufe, in every centurial year not divifible by 4, the regular courfe of leapyears is interrupted in the new; as will be the cafe in the year 1800. The cycle of Eafter, alfo called the Dionyjian period, is a revolution of 532 years, found by multiplying the folar cycle 28 by the lunar cycle 19. If the new moons did not anticipate upon this cycle, Eafter-day would always be the Sunday next after the firft full moon, which follows the 2xft of March. But, on account of the above anticipation, to which no proper regard was had before the late alteration of the ftyle, the ecclefiaftic Eafter has feveral times been a week different from the true Eafter within this laft century: which inconvenience is now remedied by making the table, which ufed to find Eafter for ever, in the Common Prayer Book, of no longer ufe than the lunar difference from the new ftyle will admit of. The earlieft Eafter poflible is the 22d of March, the lateft the 25th of April. Within thefe limits are 37 days, and the number belonging to each of them is called the number of clirettion; becaufe thereby the time of Eafter is found for any givea year. The firft feven letters of. the .alphabet are commonly placed in the annual almanacks, to (hew on v/hat days of the week the ddys of the months fall throughout the year. And becaufe one of thofe feven letters muft neceflarily ftand againft Sunday, it is printed in a capital form, and called the dominical letter: The other fix being inferred in fmall characters, to denote the other fix days of the Week. Now, fince a common Julian year contains 3^5 days, if this number be divided by 7