240 



NOTES. 



view, by the effect of the precession of the equinoxes, 

 the mere series of the signs becomes an unequivocal 

 historical document, if we at the same time suppose, 

 1st, that the nation, in which this document is found, 

 has not made use of the vague year ; 2dly, that it has 

 not thought proper to trace, after systematic ideas, the 

 ancient state of things, the point of departure, the 

 beginning of a cycle. The nations of eastern Asia 

 calculated, by means of tables of no great accuracy, 

 the position of the planets for very remote periods. 

 Their books speak of a conjunction of all the planets, 

 which seems rather the result of their calculation than 

 of observation. Is it not very possible, that a monu- 

 ment may be discovered some day or other in India, 

 on which this conjunction has been traced, without 

 our being obliged for this reason to attribute a high 

 antiquity to such a monument ? 



No passage in the ancients forms a direct proof, that 

 the Egyptians had any knowledge of the precession of 

 the equinoxes. Hipparchus made this discovery by 

 comparing his observations with those of TimocH&ris ; 

 and it is almost certain, as Mr. Delambre has recently 

 proved, that he made very few if any observations at 

 Alexandria. Though Hipparchus was indebted for 

 nothing to the Egyptian priests, it is nevertheless pro- 

 bable, that the latter would have fixed their attention 

 on the connexion, which exists between the heliacal ris- 

 ing of Sirius and the day of the summer solstice. The 

 difference between them # , in an interval of fourteen 



* The heliacal rising of Sirius was two days distant from the sol- 

 stice 2682 years before our era ; thirteen days distant, 1322 years 

 before it; and 139 years after our era, the difference amounted to 

 twenty-six days; but by happy compensations, notwithstanding the 



