A U I I C L I. \ 



Menioii explanatory ></ a /View Perpetual Calendar, ('in/ and Ecclesiastical, Julian ami 

 Gregorian. Hi/ William Mcllvaine. Read August 15, [845. 



When my attention at school was first turned to the solution of chronological problems, 

 I received a strong impression that the Dominical Letters formed too complex and cum- 

 1 nous an appendage of the calendar. According to the directions given in Pike's Arith- 

 metic, at that time a standard elementary work, one of the first seven letters of the 

 alphabet, in regular order, A always standing at the first day of January, must be pre- 

 fixed to every day in the common year of 365 days. The letter which in this series 

 happened to be affixed to the first Sunda\ in January was called the Dominical Letter 

 of that year, as marking all its Sundays, but in leap years the next following letter was 

 to serve as the Dominical Letter for the first two months of the year. A, B, ( '. D, E, F»G, 

 with 1, 2, 3, 4, 5, (5, 7, subjoined, constituted a table, the numbers being an index to the 

 letters. Ivy a rule, whose principle was left unexplained, the sum of the Julian year, it- 

 fourth part and four was to be divided by seven. Tf no remainder occurred, f« was the 

 Dominical Letter, but if any number remained that number of letters, beginning the rec- 

 koning with F, was to he counted in a retrograde order from G, to reach the Dominical 

 Letter; or on deducting the remainder from seven you migbl obtain the index of the 

 Dominical Letter, counting forwards from A. The rule was shorter for Gregorian years, 

 but in both styles the Sunday letter was double in everj leap year, and after the propel 

 letter had been found it was required to count backwards again in order to know on 

 what day of the week the first of January happened, finally, if the day of the week 

 corresponding with a given day of any other month was wanted, the tedious process of 

 tdding the day of the month to the number of days m a ]| the preceding months, and 

 dividing the sum by seven, must be gone through, and the answer deduced from anothei 

 remainder. 



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