CHRONOLOGY. 



to the second of this cycle; if then to a 

 given year of this xru one be added, and 

 the sum be divided by 19, the quotient 

 will denote the number of cycles which 

 have revolved since the commencement 

 of the Christian rera, and the remainder 

 will be the golden number for the given 

 year. e. g. If the golden number of the 

 present year (1808) be required, one be- 

 ing adde'd, the sum will be 1809 ; this be- 

 ing 1 divided by 19, will give 95 for the 

 quotient, and 4 for the remainder, or 

 golden number sought. 



The Solar Cycle is another of these pe- 

 riods, the inventor of which is at present, 

 however, unknown. It consists of 28 

 years, at the expiration of which the sun 

 returns to the sign and degree of the 

 ecliptic which he hud occupied at the 

 conclusion of the preceding period, and 

 the days of the week correspond to the 

 same days of the month as at that time. 

 It is used to determine the Sunday, or 

 dominical, letter, which we shall briefly 

 explain. 



In our present calendars the days of 

 the week are distinguished by the first 

 seven letters of the alphabet: A, 13, C, 

 D, E, F, G ; and the rule for applying 

 these letters is, invariably, to pub A for 

 the first day of the year, whatever it be, 

 B for the second, and so in succession to 

 the seventh. Should the first of January 

 be Sunday, the dominical, or Sunday, let- 

 ter for that year will be A, the Monday 

 letter B, &c. and as the number of the 

 letters is the same as that of the days of 

 the week, A will fall on every Sunday, B 

 on every Monday, &c. throughout the 

 year. Had the year consisted of 364 days, 

 making an exact number of weeks, it is 

 obvious that A would always have stood 

 for the dominical letter : the year con- 

 taining, however, one day more ; it follows 

 that the dominical letter of the succeed- 

 ing year will be G. For SundayJbeingthe 

 first day of the preceding year will be 

 also the last, and the first Sunday in the 

 next year will fallen the seventh day, 

 and will be marked by the seventh letter, 

 or G. This retrocession of the letters 

 will, from the same cause, continue 

 every year, so as to make F the domini- 

 cal letter of the third, &.c. If every year 

 were common, the process would con- 

 tinue regularly, and a cycle of seven years 

 would suffice to restore the same letters 

 to the same days as before. But the in- 

 tercalation of a day, every bissextile or 

 fourth year, has occasioned a variation in 

 this respect. The bissextile year con- 

 taining 366, instead of 365 days, will 



throw tlie dominical letter of the follow* 

 ing year back two letters ; so that, as in 

 the present year (1808), if the dominical 

 letter at the beginning of the year be C, 

 the dominical letter of the next year wilf 

 be, not B, but A. This alteration is not 

 effected by dropping a letter altogether, 

 but by changing the dominical letter at 

 the end of February, where the interca- 

 lation of a day takes place. Thus, in the 

 present year, C is the dominical letter in 

 January and February, but B is substi- 

 tuted for it in March, and continues to 

 be the dominical letter through the re- 

 mainder of the year. In consequence 

 of this change every fourth year, twenty- 

 eight years must elapse, before a com- 

 plete revolution can take place in the 

 dominical letter, and it is on this circum- 

 stance that the period of the solar cycle 

 is founded. A table constructed to shew 

 the dominical letters, for any given years 

 of one of these cycles, will answer for the 

 corresponding years in every successive 

 cycle. The first year of the Christian 

 sera corresponds to the ninth of this cy- 

 cle ; if, therefore, to any given year of 

 the Christian zera nine be added, and the 

 sum be divided by 28, the quotient will 

 denote the number of the revolutions of 

 the cycle since the ninth year B. C. and 

 the remainder will be the year of the cy- 

 cle. If there be no remainder, the year 

 of the cycle will be the last, or twenty- 

 eight, e. : Nine being added to 1808, 

 makes 1817 ; this sum being divided by 

 28, gives a quotient of 64 for the revolu- 

 tions of the cycle, and a remainder of 25 

 for the year of the cycle. There is ano- 

 ther cycle in use, called 



The Cycle of Infection. It consists of 

 fifteen years, and is. derived from the Ro- 

 mans. Learned men are not agreed as to 

 the origin of it, but the most probable opi- 

 nion is, that the return of this period was 

 appointed for the payment of some public 

 taxes or tributes. The first year of this 

 cycle is made to correspond to the year 

 SBC. If therefore to any given year of 

 the Christian XVA 3 be added, and the sum 

 be divided by 15, the remainder will be 

 the year of tliis cycle. There is however 

 another mode of calculating it. This cycle 

 was established by Consj:antine A. D. 312; 

 if therefore from the given year of the 

 Christian sera 312 be subtracted, and the 

 remainder be divided by 15, the year of 

 this cycle will be obtained. In either of 

 these ways, if there be no remainder, the 

 indiction will be 15. We subjoin an ex- 

 ample, calculated by each. of the methods 

 above specified. 



