THE SOURCE OF THE NILE. 687 
in common ufe, and this, too, I conceive to be Strabo’s: mean- 
ing. But let ws compute from Herodotus, who: fays that 
16, or at leaft 15, were neceflary in his time, whilft Strabo 
informs us, that, before Petronius exerted himfelf as to the 
banks and califhes juft mentioned, the extreme abundance 
muft then have been at 12, and the minimum at 10. Now, by 
this paflage, beyond all excep.ion, itis clear that there could 
have been no increafe indicated by the Nilometer; for 10 
cubits watered the whole land’of Egypt fufficiently in Stra- 
_bo’s time, whereas. 16 and. 15. were neceffary. in the days 
of %.exzodotus: and I mutt likewife obferve, that if we fhould 
fuppofe the fame induftry and attention: ufed in Meris’s time 
that was in Petronius’s, (and there is: every reafon to induce 
us to think there was): then the proof is pofitive, that there 
was. no difference in the foil:of Egypt.indicated by the Ni- 
lometer for the firft 1400 years.. 
From this let us defcend to Hadrian, about rooyears after- 
wards.. We know from Pliny*, and from an infcription 
upon a medal of great brafs of Hadrian’s, who was himfelf 
in Egypt, that 16 cubits were then the fifcal term or rife of 
the Nile, by which the Egyptians paid their rent; and this 
is precifely what Herodotus fays, in his time, was no more 
than fufficient. 
Azsout the beginning of the 4th century, in the emperor 
Julian’s reignt, 15 cubits were a fuflicient minimum to in- 
cur the payment of the tribute, and this is one of the terms 
Wo Ub cA est that 
* Plin, Jib. xxxvi. cap. 7. Philoft. de icon. Nilt. 
+} Julian. Epift. egdicio prefecto Egypti. 
nm 
