Idumasa, then, was the tract south and south-west of Palestine from
about lat. 31° 10'. It reached westward to the borders of Egypt, which
were at this time marked by the Wady-el-Arish, southward to the range of
Sinai and the Elanitic Gulf, and eastward to the Great Desert. Its
chief town was Petra, in the mountains east of the Arabah valley. The
character of the tract is for the most part a hard gravelly and rocky
desert; but occasionally there is good herbage, and soil that admits of
cultivation; brilliant flowers and luxuriantly growing shrubs bedeck the
glens and terraces of the Petra range; and most of the tract produces
plants and bushes on which camels, goats, and even sheep will browse,
while occasional palm groves furnish a grateful shade and an important
fruit. The tract divides itself into four regions--first, a region of
sand, low and flat, along the Mediterranean, the Shephelah without
its fertility; next, a region of hard gravelly plain intersected by
limestone ridges, and raised considerably above the sea level, the
Desert of El-Tin, or of "the Wanderings;" then the long, broad, low
valley of the Arabah, which rises gradually from the Dead Sea to an
imperceptible watershed, and then falls gently to the head of the
Gulf of Akabah, a region of hard sand thickly dotted with bushes, and
intersected by numerous torrent courses; finally a long narrow region
of mountains and hills parallel with the Arabah, constituting Idumsea
Proper, or the original Edom, which, though rocky and rugged, is full
of fertile glens, ornamented with trees and shrubs, and in places
cultivated in terraces. In shape the tract was a rude square or oblong,
with its sides nearly facing the four cardinal points, its length from
the Mediterranean to the Gulf of Akabah being 130 miles, and its width
from the Wady-el-Arish to the eastern side of the Petra mountains 120
miles. The area is thus about 1560 square miles.

Beyond the Wady-el-Arish was Egypt, stretching from the Mediterranean