50 UNIVERSAL ERUDITION. 



four cardinal points, the new and full moons, 

 the relative petitions of the planets, and other 

 celeftial phenomena, can be calculated to the 

 greateft precifion, they may be regarded as in- 

 fallible marks of time. Therefore, when we 

 know the. year of any people, and find a fact re- 

 lated by an author according to the chronologic 

 elate of another people, and that author alfo 

 makes mention of another event that happened 

 at the fame time among the former people, we 

 may find, by the known year of one of thefe 

 people, the unknown year of the other. Accord- 

 ing to thefe two methods of calculating, we may 

 alfo find, by years that are known, how many 

 years have paffed between them and the time 

 any event has happened, the precife date of 

 which has not been marked by hiftorians. For 

 example, the year that a prince came to the 

 crown may not be mentioned in the annals, but 

 we may find that in a certain known year of his 

 reign there was a remarkable eclipfe of the fun ; 

 from whence we may eafily calculate the precife 

 year that he began to reign. 



XXII. Mathematic chronology teaches us, 

 moreover, the method of reducing, by means of 

 calculation, the different years arid periods of 

 different people to one common meafure-, to 

 compare the one with the other, and thus to find 

 the precife time in which every event recorded 

 in hiftory has arrived. By thtfe means we are 

 enabled not only to range the facts of various 



nations, 



