666 PROCEEDINGS OF SECTION F, 



of the week later than Jst January, 1st April six days, and 

 so on. Opposite the first seven days of January are placed 

 the seven days of the week in every possible combination. 

 Now, when 2nd September falls on a Sunday, as we saw in 

 the case of the year 1666, 1st September falls on Saturday, 

 and Table A shows that when 1st September falls on Saturday, 

 1st January falls on Monday, provided the year be not a 

 Leap Year, which 1666 is not. 



Having arrived at the day for a year before the alteration 

 in the calendar. Table B gives the days for all the years from 

 1600 to 1800, which shows the day for 1700 to be Monday, 

 and for 1600 Tuesday. It follows that as we go back in the 

 calendar, a day of the week is gained in every centurial year, 

 and by taking a century at a time Table C shows the day for 

 the year 600 to be Friday. I will now put 6 opposite Friday 

 with C over it to denote 600.* For the same reason 5 will 

 go opposite Saturday, 4 opposite Sunday, 3 Monday, 2 

 Tuesday, 1 Wednesday, and opposite Thursday. As a day 

 of the week is gained in 100 years, seven days are gained in 

 700, and the day of the week therefore repeats itself every 

 700 years. This column, then, serves to show the days for 

 the centurial years till 1700, if we divide them by 7 and take 

 the remainder ; and as each was Leap Year, we give each a 

 second day, and commence with the year 400, as most con- 

 veniently placed, to arrange the units. 



If the days for 400 were Sunday and Monday, the day for 

 401 would be Tuesday, so we place Tuesday under 1, Wed- 

 nesday under 2, Thursday 3, Friday and Saturday under 4, 



5 over Sunday, 6 over Monday, 7 Tuesday, 8 Wednesday, 

 and Thursday, 9 over Friday, and 10 helow Saturday. But 

 as every centurial year is Leap Year, with only one day's 

 difference between each, we may employ the same units for 

 each as far as ten years, and if we complete our square, 

 the difference of one day between each year, and one 

 between each century, still remains. The day for 410 we 

 found to be Saturday, but as this is not Leap Year, we 

 require a fresh group of units. Having found Saturday 

 in the left-hand column, we place over it to stand for 

 410, then 1 and 2 over Sunday, Monday, and Tuesday 

 for 411, 412; 3, 4, 5 over Wednesday, Thursday, Friday, 



6 over Saturday, 7, 8, 9 over Monday, Tuesday, Wed- 



* By substituting the seven days of the week for the seven letters in the 

 square, this may be seen in the Luneral, where T representing Friday, in the 

 left-hand column of letters is found opposite 6 under c b. 



