EXAMPLES.
Example No. 1.—What day of the week was the 21st of June, 1581?
| 1500—key | 1 | in Table 1. |
| 81—key | 3 | in Table 2. |
| June—key | 0 | in Table 3. |
| Total | 4, | the three keys added. |
This 4 is the key for [Table 4], where, on the right-hand side of this key, under the 21 st day, we find Wednesday.
If the three keys together make more than 6, seven is subtracted; and if more than 13, fourteen is deducted, and the remainder is the key to [Table 4].
Thus we find June 6th, 1839, through 0 + 6 + 0 = 6, = Thursday.
August 9th, 1732, through 6 + 5 + 5 = 16, - 14 = 2 = Wednesday.
Columbus sailed from Palos on Friday, August 3rd, 1492, and discovered America on the 12th of October, 1492, which was also a Friday.
Example No. 2.—In what years will Christmas Day fall on a Sunday? [Table 4] shows, below the 25th, the Sunday on the side of key 4; subtract the key of December, which is 1, there remains, for the present century, the key 3 of [Table 2], showing the years 1887, 1892, 1898 and as this 4 for the next century will come from 5 + x + 1 minus 7, it follows that x means the key 5 in [Table 2], which contains the years 1904, 1910, 1921, and the other years in that column.
We found the 6th of June, 1839, to be a Thursday, and see from the last column of [Table 2] that it was again on a Thursday in 1844, 1850, 1861, etc.