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

ON THE DIVISIONS AND MEASURES OF TIME.

19

number of years. The correction, however, will be inconsiderable
for many ages, as it will amount only to a day and a half to be
suppressed in the space of 5000 years.
The modern Hebrew Calendar was settled by Rabbi Hillel, about
the middle of the fourth century of the Christian era, and is founded
on the periods of the moon and the sun. It is so arranged that the
festival of the Passover should be celebrated on the day of the new
moon at the vernal equinox, or on the day nearest to the day of the
moon's conjunction with the sun. The months are arranged, some of
29 days, and others of 30 days. The intercalary year had an additional month, called Ve-Adar. This intercalary month is placed
between the months Adar and Nisan, and consists of 29 days in
common years and of 30 days in intercalary years. According to the
scheme of Rabbi Hillel, a common year may consist of 353, 354, or
355 days, and an intercalary year of 383, 384, or 385 days; but his
rules and limitations secure the reckonings of the calendar from any
inconvenient discrepancy with the seasons.
The most recent scheme for the reform of the calendar was made
at the French Revolution, and lasted about fourteen years. The first
fruits of this Revolution were the constitution of the National Convention, the deposition of the king in 1792, and France declared to be a
Republic. These proceedings were followed by the murder of the
king and the queen at Paris in the following year. The Convention of
the Republic, by two decrees issued on 5th Oct. and on 24th Nov., 1793,
abolished the old calendar, which reckoned from the epoch of the
birth of Christ, and decreed a new calendar, on what they considered
true philosophical principles. But from the inconveniences arising out
of the regularity of the motion of the earth on its axis and in its orbit
round the sun, and of the moon round the earth, they could only
change names, and decree minor subdivisions of time, and begin the
year at a different epoch. Accordingly it was decreed that the era of
the Revolution, 22nd September, 1792, should be distinguished as the
first day of the year of the French Republic, being the day of the
autumnal equinox.
The year was divided into 12 months, of 30 days each, with five
complementary days. The leap years were styled Olympic years. The
following descriptive epithets they gave to their new months are not
new names, but merely an imitation of the old Dutch names.
Vind(miare,vintacgemonth,began 22 Sept. Germinal, budding month, began 21 Mar.
Brumaire, foggy, 22 Oct. Floreal, flowery,, 20 April
Frimaire, sleety,, 21 Nov. Prarial, meadow,, 20 May
Nivose, snowy,, 21 Dec. Messidor, harvest,, 19 June
Pluvi6se, rainy, 20 Jan. Thermidor, hot,, 19 July
Vent6se, windy,, 19 Feb. Fructidor, fruit,, 8 Aug.
The new calendar appointed the five complementary days of the
ordinary years to be celebrated as festivals: the 17th September dedicated to Virtue, the 18th to Genius, the 19th to Labour, the 20th to
Opinion, and the 21st to Rewards.
In every Olympic year from 11 Ventase (29th Feb.) to the end of
the year, each day of the month was one day earlier than in ordinary
years, and there were six instead of five festival days. It is curious
to remark that the designation of sanss-czottides (taken from sansculottes) was given to these festival days. The name at first had been