etachment of fifteen
hundred light-armed soldiers, whose active vigilance observed the
most distant signs, and conveyed the earliest notice, of any hostile
approach. Dagalaiphus, and Secundinus duke of Osrhoene, conducted
the troops of the rear-guard; the baggage securely proceeded in the
intervals of the columns; and the ranks, from a motive either of use
or ostentation, were formed in such open order, that the whole line of
march extended almost ten miles. The ordinary post of Julian was at the
head of the centre column; but as he preferred the duties of a general
to the state of a monarch, he rapidly moved, with a small escort of
light cavalry, to the front, the rear, the flanks, wherever his presence
could animate or protect the march of the Roman army. The country which
they traversed from the Chaboras, to the cultivated lands of Assyria,
may be considered as a part of the desert of Arabia, a dry and barren
waste, which could never be improved by the most powerful arts of human
industry. Julian marched over the same ground which had been trod above
seven hundred years before by the footsteps of the younger Cyrus, and
which is described by one of the companions of his expedition, the sage
and heroic Xenophon. "The country was a plain throughout, as even as the
sea, and full of wormwood; and if any other kind of shrubs or reeds
grew there, they had all an aromatic smell, but no trees could be seen.
Bustards and ostriches, antelopes and wild asses, appeared to be the
only inhabitants of the desert; and the fatigues of the march were
alleviated by the amusements of the chase." The loose sand of the desert
was frequently raised by the wind into clouds of dust; and a great
number of the soldiers of Julian, with their tents, were suddenly thrown
to the ground by the violence of an unexpected hurricane.

The sandy plains of Mesopotamia were abandoned to the antelopes and wild
asses of the desert; but a variety of populous towns and villages were
pleasantly situated on the banks of the Euphrates, and in the islands
which are occasionally formed by that river. The city of Annah, or
Anatho, the actual residence of an Arabian emir, is composed of two long
streets, which enclose, within a natural fortification, a small island
in the midst, and two fruitful spots on either side, of the Euphrates.
The warlike inhabitants of Anatho showed a disposition to stop the march
of a Roman emperor; till they were diverted from such fatal pr