THE SOURCE OF THE NIL, 605 
mined by the inveftigation of the caufe, and the obferva- 
tions of a feries of years. Before this was thoroughly fet- 
tled and known, the farmer might perhaps cultivate the 
plain of Egypt, but would not build there; he would fix his 
dwelling on the mountain in defiance of the flood; and that 
this was fo,.is evident from what we faw at Thebes, which 
the Aborigines did not build, as we fee thoufands of caves 
dug out of folid rock that were the dwellings of the firft 
inhabitants, the Troglodytes, beyond Meroé. 
Tue philofophers of Meroé feem-therefore to have been 
the firft that undertook the compiling a feries of obferva- 
tions, which fhould teach their pofterity the proper times 
in which they could fettle in, and cultivate Egypt; without 
fear of danger from the Nile. That ifland, full of flocks 
and fhepherds, under a {ky perpetually. cloudlefs; having a 
twilight of {hort duration, was placed between the Nile and 
Aftaboras, where the two rivers-colleé&.the waters that fall 
in the eaft and the weft.of Ethiopia, and mix together in a 
latitude where the tropical.rains ceafe; this land was too. 
’ high to be overflowed by the Nile, but near enough to be- 
hold every alteration in that_river’s increafe from the in- 
 flant it happened... 
Sirius, the brighteft flar in the Heavens, probably the 
largeft, perhaps the neareft to us, in either cafe the moft ob- 
vious and ufeful for the prefent purpofe,. was inimediately 
vertical to Meroé ; and it did not long efcape obfervation, 
that the heliacal rifing of the dog-flar was found to be the 
inftant when all Egypt was to prepare for the reception of 
a firanger-flood, without which the. hufbandman’s labour 
and expectation of harveft were in vain. The fields were 
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