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historical document, if we at the same time suppose, 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 Timocharis ; 
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 
