146 DESCRIPTIONS OF EGYPT* 
eastern or Elanitic gulf, Aila, from which it de- 
rives its name, was situated* Kolzoum is situated 
near the extremity of the larger gulf, which, in an- 
cient authors, is commonly denominated that of 
Heroopolis. By the Arabic authors, both the ci- 
ties of Kolzoum and Aila are included within the 
boundaries of Egypt. The retreat of the Red 
Sea, on the Arabian side, gradually increases the 
breadth of the isthmus ; though the inaccurate ac- 
counts of the Grecian and Arabian geographers 
seem to support the opinion, that it has rather en- 
croached upon the land in that quarter, than de- 
serted it. Misled by the opinion, that Mount 
Casius and Heroopolis, a city near the bottom of 
the gulf, lay under the same meridian, though 
there be almost a degree of longitude between 
them, Herodotus and Ptolemy have extended the 
distance between Mount Casius and the head of the 
Arabian gulf, to eighty-three instead of sixty-four 
G. miles. From the respective latitudes of Suez 
and Farama, the ancient Pelusium, the nearest 
distance between the Red Sea and the Mediterra- 
nean appears to be about forty-eight G. miles. 
The intermediate space is a level plain, covered 
with shifting sand, which the eye traverses without 
interruption from sea to sea. The advantages 
which this situation presented for commercial pur- 
suits, did not escape the observation of the an- 
cients, and, at a very early period, a canal was 
n 
