was of imposing height, and from this vantage-ground galled the Romans in the town with an incessant shower of arrows, darts, and stones.  The ordinary catapults and balistae of the Romans were no match for such a storm descending from such a height; and it was plainly necessary, if the place was to be taken, to have recourse to some other device.  Julian, therefore, who was never sparing of his own person, took the resolution, on the second day of the siege, of attempting to burst open one of the gates.  Accompanied by a small band, who formed a roof over his head with their shields, and by a few sappers with their tools, he approached the gate-tower, and made his men commence their operations.  The doors, however, were found to be protected with iron, and the fastenings to be so strong that no immediate impression could be made; while the alarmed garrison, concentrating its attention on the threatened spot, kept up a furious 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