COMMON THINGS THE ALMANACK. 



42. The DOMINICAL, or SUNDAY LETTER, which appears prefixed 

 to the calendar, is an expedient by which the days of the week, 

 which fall upon the successive days of any proposed year, past or 

 future, may be determined. This expedient has a close relation 

 with the solar cycle just explained. 



If the general calendar usually prefixed to the Book of Common 

 Prayer of the Established Church be referred to, it will be seen, 

 that in the column which follows that of the numbers expressing" 

 the days of the month, the first seven letters of the Alphabet, 

 A, B, c, D, E, F, and G, are annexed, and are continually repeated, 

 for every successive series of seven days to the end of the year ; 

 the intercalary day of the 29th of February, in the case of a leap 

 year, being, however, past over, and the letter which succeeds 

 that annexed to 28th February being annexed to 1st March, as it 

 would if the year were a common year of 365 days. 



Now, if these seven letters be supposed to express the seven 

 successive days of the week upon which the first seven days of the 

 year fall, they will express equally the days of the week upon 

 which all the succeeding days of the year fall, when it is a common, 

 year of 365 days, which we shall for the present suppose it to be, 

 and the same letter throughout the year will everywhere express 

 the same day of the week. Thus, if the 1st January fall on 

 Sunday, the letter A, which is annexed to the 1st January, being^ 

 also annexed to every seventh successive day to the end of the 

 year, all these days must be Sundays. 



In the same manner, the letter B being annexed to the 2nd 

 January, that day being Monday, the same letter B will be found 

 after every seventh succeeding day to the end of the year, and, 

 therefore, all such days having B annexed will be Mondays. 



It will be evident that like inferences will be applicable to the 

 days marked by the other letters, and that similar consequences 

 would follow if the 1st January were supposed to fall upon any 

 other day. 



Whatever, therefore, be the day from the 1st to 7th January, 

 inclusive, upon which Sunday may happen to fall, the letter 

 found annexed to that day will be found annexed to all the suc- 

 ceeding Sundays in the year ; and consequently, if the day of the 

 first seven on which the Sunday falls be known, the letter annexed 

 to it will make known without further computation all the Sundays 

 in the year. 



This letter has therefore been called the DOMINICAL, or SUNDAY 



LETTER. 



43. But we have here supposed the year to be a common year 

 of 365 days. If it be a leap year, the case will be different. 

 In that case the letter which is annexed to the 1st March, will 



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