Elementary arithmetic, with brief notices of its history... by Robert Potts.

18

ON THE DIVISIONS AND MEASURES OF TIME.

By this correction of the Julian Calendar, the 14th day of the paschal
moon was brought back to the same season in which it was found at
the Council of Nicsea. The decree of that Council declared that
Easter ought to be kept on the first Sunday after the 14th day of this
moon, if this 14th day should happen on or after the 21st March. It
will lence appear that according to this rule, Easter Sunday cannot
happen earlier than the 22nd March nor later than the 25th April,
which have been called the paschal limits.
The calendar, as corrected by Gregory XIII., is called the Gregorian
Calendar, or" the New Style, "and as corrected by Julius Cuesar is called
the Julian Calendar, or "the Old Style." The Old Style was formally
abrogated in 1582, and the New Style was adopted in all countries
where the Papal supremacy was acknowledged. The Protestant States
of Germany at first rejected it, as they did everything that bore any
semblance of Papal authority, and did not adopt the New Style until
the month of February, 1700.
In England until 1752 there were two beginnings of the year, one
on the 25th March, and the other on the 1st day of January. Great
inconveniences were experienced from having two modes of reckoning.
At length in 1752 an Act of Parliament was passed, entitled an Act
(23 Geo. II.) for regulating the commencement of the year, and for
correcting the calendar. It declared that "Easter day, on which the
rest depends, is always the first Sunday after the first full moon which
happens upon or next after the 21st day of March; and if the full
moon happens upon a Sunday, Easter day is the Sunday after." But
as 170 years had elapsed since the epoch of the Gregorian correction,
the Old Style had gained one additional day more on the course of the
sun than it had at that epoch. By the Act it was therefore ordered
that eleven days should be dropped. And accordingly, on the 2nd
day of September, 1752, the " Old Style " ceased, and the next day,
instead of the 3rd, was called the 14th September of the "New Style."
By the same Act the beginning of the year was changed from the
25th March to the first day of January, and its reception encountered
much opposition through the prejudices of people of all ranks-rich
and poor, high and low;1 and these feelings in no small degree arose
from the fact of the change having originated with the Bishop of
Rome. The calendar, so corrected, has ever since 1757 been printed
at the beginning of the Book of Common Prayer.
The method of intercalation used in the Gregorian Calendar is not
the most accurate, as 97 or 100 - 3 days are inserted in the space of
four centuries. This supposes the tropical year to consist of 365 days,
5 hours, 49 min., 12 sec.: but the reformers of the calendar made
use of the Copernican year, 365 days, 5 hours, 49 minutes,
20 seconds. Recent observations have determined the length of
the tropical year to be 365 days, 5 hours, 48 min., 45- sec., and if
41,851 days be intercalated in 172,800 years, there would be no error.
As this mode of intercalation is different from that now in use, it is
obvious that the Gregorian Calendar must be corrected after a certain
I On the adoption of the New Style in 1752, by Act of Parliament, it was orderedc
that the third day of September should be accounted as the fourteenth. This gave
intense offence to the ignorant multitude, some of whom believed that eleven days
were thus taken fro m. teir lives against their will by Act of Parliament. Hogarth,
the celebrated painter, to ridicule this absurdity, represented them in one of his
pictures, vociferating " Give us back our eleven days."