174 taken from 30 will leave 12 days of June, for the time of the new moon: but as in astronomical computation the day begins at the noon after the commencement of the common day, 12 days will coincide with the beginning of the 13th day of the month; and in fact, the true time of new moon is found, by accurate calculation, to happen about 4 in the morning of the 13th of June, 1809. Were it required to discover the moon's age on any given day, as the 25th of June of the same year, we have only to count the days from that of the change, and the difference 12, is the moon's age on the given day. Again, to find the age of the moon on Christmas-day, 1809, we add together the epacts for the year or 14, for the month preceding December or 9, and the day of the month 25, making together 48 days, from which subtracting 30, the remainder gives the moon's age 18 days, for 25th December, 1809. In almanacs, it is usual to place certain letters of the alphabet before the several days of the months: these are the letters, A B C D E F and G, seven in number, equal to the days in the week. The first day of January is always marked A, the second B, and so on to the seventh, G, then the eight day begins with A, the ninth is B, and the 14th G as before. If the first of January be a Sunday, then will the eighth day be also a Sunday, and marked A in the calendar: hence A will through the whole year denote the Sundays, and so be called the Sunday or dominical letter for that year. Had every year consisted of 364 days or 52 weeks, it is evident that the year would always have begun on the same day of the week, and that the dominical or Sunday letter would always have been the same: but common years consisting of 365 days, if the year begin on a Sunday, it will end on the same day, and the following year will begin on a Monday; consequently if the dominical letter of the VOL. 11. 2 L first first year be A, that of the second year will be G. In leap years however consisting of 366 days, if the first day be Sunday or A, the last day will be Monday or B, and the first day of the ensuing year will be Tuesday, and the dominical letter will be F. In leap-years, also, are two dominical letters, the first serving from the beginning of the year to the end of February, and the second for all the rest of the year. This is occasioned by the intercalation of a day, counted the 29th of February: to which is given the samne letter with that of the 28; for if the first of January were Sunday, and A the dominical letter, the 28th of February would fall on Tuesday the 3d day of the week or C, and the 29th or Wednesday, being intercalated with the same letter C repeated, Thursday the 1st of March will be D, Friday E, Saturday F, and Sunday will be G. By this process we find for the leap-year two Sunday or dominical letters A and G, the former to be used in January and February, and the latter in all the other months of the year. The preceding rules give the yearly and monthly epacts in round numbers, near enough the truth for ordinary purposes: in the following tables, however, they are stated agreeably to accurate computation, in days, hours, and minutes, for the years 1808 to 1850, both included. YEARLY In this table the years to which the letter B is prefixed are N. B. In leap-years one day must be subtracted from the sum of the epacts in the months of January and February. These tables contain the mean epacts on the supposition that the moon's motion in her orbit is regular and equable, and performed in the time of 29 days 12 hours 44 minutes 3 seconds. For determining the dates of events in the world, various epochs or points of time from its commencement have been selected. The principal of these is the creation of this world, which according to the best computations of the learned, took place about 4008 years before the beginning of the Christian era. In this determination modern chronologers have been confined to follow the Mosaic history in the old Testament, which independently of its divine original contains the only rational and consistent account of events from the earliest periods of time, any where to be found; for the histories of the Chinese, the Egyptians, the Babylonians, the Indians, and other nations laying claim to the highest antiquity are evidently filled with the grossest contradictions and absurdities. Our common era reckoned from the birth of our Saviour was not adopted until so late as about the year 527, when Dionysius, abbot of a monastery in Rome, first settled and introduced that mode of counting time. In settling this point, however, it appears he committed an error of 4 years, placing Christ's birth so much later than the truth: if then the Creation took place 4004 years, as is generally computed, before the birth of Christ, it must have happened 4008 years before the commencement of the Christian era; and the year 1809 ought in strictness to be counted the 1813th year from the birth of our Saviour. When therefore we speak of any event as occurring in any given year of Christ we me such a year of the Christian era as settled by Dionysius, and by adding 4 to the number we obtain the year from the true epoch of our Saviour's birth. The Greeks made use of a period called an Olympiad, which was a space of 4 years, at the end of which were celebrated celebrated the Olympic games, near the city Olympia on the western coast of the Peloponnesus. These games were said to have been instituted by Hercules in honour of Jupiter: but being afterwards discontinued for a time, they were revived in the year 776, before the Christian era, from which time they were celebrated every 5th year without interruption; and computation by Olympiads may be traced in the history of Greece down to the 440th year of Christ. Amongst the Romans it was the practice to date events from the year of the foundation of the city, corresponding to year 753, before the Christian era. The Arabians, Turks, and many other oriental nations, reckon their time from the flight of Mahomet from Mecca to Medina, which happened in the year 622 of the Christian era: but the Persians compute by the era of Jesdegird, beginning in the year 632. The following is a list of a few of the most important events in the history of the world, from the creation to the present time: Dedication of Solomon's temple at Jerusalem 1008 776 Era |