ious
discharge of missiles on their daring assailants. Prudence counselled
retreat from the dangerous position which had been taken up; and the
emperor, though he felt acutely the shame of having failed, retired.
But his mind, fertile in resource, soon formed a new plan. He remembered
that Demetrius Poliorcetes had acquired his surname by the invention and
use of the "Helepolis," a movable tower of vast height, which placed the
assailants on a level with the defenders even of the loftiest ramparts.
He at once ordered the construction of such a machine; and, the ability
of his engineers being equal to the task, it rapidly grew before his
eyes. The garrison saw its growth with feelings very opposite to
those of their assailant; they felt that they could not resist the new
creation, and anticipated its employment by a surrender, Julian agreed
to spare their lives, and allowed them to withdraw and join their
countrymen, each man taking with him a spare garment and a certain
sum of money. The other stores contained within the walls fell to the
conquerors, who found them to comprise a vast quantity of corn, arms,
and other valuables. Julian distributed among his troops whatever was
likely to be serviceable; the remainder, of which he could make no use,
was either burned or thrown into the Euphrates.

The latitude of Ctesiphon was now nearly reached, but Julian still
continued to descend the Euphrates, while the Persian cavalry made
occasional dashes upon his extended line, and sometimes caused him a
sensible loss. At length he came to the point where the Nahr-Malcha, or
"Royal river," the chief of the canals connecting the Euphrates with the
Tigris, branched off from the more western stream, and ran nearly due
east to the vicinity of the capital. The canal was navigable by his
ships, and he therefore at this point quitted the Euphrates, and
directed his march eastward along the course of the cutting, following
in the footsteps of Severus, and no doubt expecting, like him, to
capture easily the great metropolitan city. But his advance across the
neck of land which here separates the Tigris from the Euphrates was
painful and difficult, since the enemy laid the country under water, and
at every favorable point disputed his progress. Julian, however, still
pressed forward, and advanced, though slowly. By felling the palms which
grew abundantly in this region, and forming with them rafts supported
by inflated skins, he was able to