reunite his forces. He understood the Gauls, and foresaw what must have happened.
Labienus, when sent on his separate command, had made Sens his head- quarters. All down the Seine the country was in insurrection. Leaving the new Italian levies at the station, he went with his experienced troops down the left bank of the river till he came to the Essonne. He found the Gauls entrenched on the other side, and, without attempting to force the passage, he marched back to Melun, where he repaired a bridge which the Gauls had broken, crossed over, and descended without interruption to Paris. The town had been burnt, and the enemy were watching him from the further bank. At this moment he heard of the retreat from Gergovia, and of the rebellion of the Aedui. Such news, he understood at once, would be followed by a rising in Belgium. Report had said that Caesar was falling back on the province. He did not believe it. Caesar, he knew, would not desert him. His own duty, therefore, was to make his way back to Sens. But to leave the army of Gauls to accompany his retreat across the Seine, with the tribes rising on all sides, was to expose himself to the certainty of being intercepted. "In these sudden difficulties," says Caesar, "he took counsel from the valor of his mind." [6] He had brought a fleet of barges with him from Melun. These he sent down unperceived to a point at the bend of the river four miles below Paris, and directed them to wait for him there. When night fell he detached a few cohorts with orders to go up the river with boats as if they were retreating, splashing their oars, and making as much noise as possible. He himself with three legions stole silently in the darkness to his barges, and passed over without being observed. The Gauls, supposing the whole army to be in flight for Sens, were breaking up their camp to follow in boisterous confusion. Labienus fell upon them, telling the Romans to fight as if Caesar was present in person; and the courage with which the Gauls fought in their surprise only made the overthrow more complete. The insurrection in the north-west was for the moment paralysed, and Labienus, secured by his ingenious and brilliant victory, returned to his quarters without further accident. There Caesar came to him as he expected, and the army was once more together.
Meanwhile the failure at Gergovia had kindled the enthusiasm of the central districts into white-heat. The Aedui, the most powerful of all the tribes, were now at one with their countrymen, and Bibracte became the focus of the national army. The young Vercingetorix was elected sole commander, and his plan, as before, was to starve the Romans out. Flying bodies harassed the borders of the province, so that no reinforcements could reach them from the south. Caesar, however, amidst his conquests had the art of making staunch friends. What the province could not supply he obtained from his allies across the Rhine, and he furnished himself with bodies of German cavalry, which when mounted on Roman horses proved invaluable. In the new form which the insurrection had assumed the Aedui were the first to be attended to. Caesar advanced leisurely upon them, through the high country at the rise of the Seine and the Marne, toward Alesia, or Alice St. Reine. Vercingetorix watched him at ten miles' distance. He supposed him to be making for the province, and his intention was that Caesar should never reach it. The Celts at all times have been fond of emphatic protestations. The young heroes swore a solemn oath that they would not see wife or children or parents more till they had ridden twice through the Roman army. In this mood they encountered Caesar in the valley of the Vingeanne, a river which falls into the Sane, and they met the fate which necessarily befell them when their ungovernable multitudes engaged the legions in the open field. They were defeated with enormous loss: not they riding through the Roman army, but themselves ridden over and hewn down by the German horsemen and sent flying for fifty miles over the hills into Alice St. Reine. Caesar followed close behind, driving Vercingetorix under the lines of the fortress; and the siege of Alesia, one of the most remarkable exploits in all military history, was at once undertaken.
Alesia, like Gergovia, is on a hill sloping off all round, with steep and, in places, precipitous sides. It lies between two small rivers, the Ose and the Oserain, both of which fall into the Brenne, and thence into the Seine. Into this peninsula, with the rivers on each side of him, Vercingetorix had thrown himself with eighty thousand men. Alesia as a position was impregnable except to famine. The water-supply was secure. The position was of extraordinary strength. The rivers formed natural trenches. Below the town to the east they ran parallel for three miles through an open alluvial plain before they reached Brenne. In every other direction rose rocky hills of equal height with the central plateau, originally perhaps one wide table-land, through which the water had ploughed out the valleys. To attack Vercingetorix where he had placed himself was out of the question; but to blockade him there, to capture the leader of the insurrection and his whole army, and so in one blow make an end with it, on a survey of the situation seemed not impossible. The Gauls had thought of nothing less than of being besieged. The provisions laid in could not be considerable, and so enormous a multitude could not hold out many days.
At once the legions were set to work cutting trenches or building walls as the form of the ground allowed. Camps were formed at different spots, and twenty-three strong block-houses at the points which were least defensible. The lines where the circuit was completed were eleven miles long. The part most exposed was the broad level meadow which spread out to the west toward the Brenne river. Vercingetorix had looked on for a time, not understanding what was happening to him. When he did understand it, he made desperate efforts on his side to break the net before it closed about him. But he could do nothing. The Gauls could not be brought to face the Roman entrenchments. Their cavalry were cut to pieces by the German horse. The only hope was in help from without, and before the lines were entirely finished horsemen were sent out with orders to ride for their lives into every district in Gaul and raise the entire nation. The crisis had come. If the countrymen of Vercingetorix were worthy of their fathers, if the enthusiasm with which they had risen for freedom was not a mere emotion, but the expression of a real purpose, their young leader called on them to come now, every man of them, and seize Caesar in the trap into which he had betrayed himself. If, on the other hand, they were careless, if they allowed him and his eighty thousand men to perish without an effort to save them, the independence which they had ceased to deserve would be lost forever. He had food, he bade the messengers say, for thirty days; by thrifty management it might be made to last a few days longer. In thirty days he should look for relief.
The horsemen sped away like the bearers of the fiery cross. Caesar learnt from deserters that they had gone out, and understood the message which they carried. Already he was besieging an army far outnumbering his own. If he persevered, he knew that he might count with certainty on being attacked by a second army immeasurably larger. But the time allowed for the collection of so many men might serve also to prepare for their reception. Vercingetorix said rightly that the Romans won their victories, not by superior courage, but by superior science. The same power of measuring the exact facts of the situation which determined Caesar to raise the siege of Gergovia decided him to hold on at Alesia. He knew exactly, to begin with, how long Vercingetorix could hold out. It was easy for him to collect provisions within his lines which would feed his own army a few days longer. Fortifications the same in kind as those which prevented the besieged from breaking out would serve equally to keep the assailants off. His plan was to make a second line of works--an exterior line as well as an interior line; and as the extent to be defended would thus be doubled, he made them of a peculiar construction, to enable one man to do the work of two. There is no occasion to describe the rows of ditches, dry and wet; the staked pitfalls; the cervi, pronged instruments like the branching horns of a stag; the stimuli, barbed spikes treacherously concealed to impale the unwary and hold him fast when caught, with which the ground was sown in irregular rows; the vallus and the lorica, and all the varied contrivances of Roman engineering genius. Military students will read the particulars for themselves in Caesar's own language. Enough that the work was done within the time, with the legions in perfect good humor, and giving jesting names to the new instruments of torture as Caesar invented them. Vercingetorix now and then burst out on the working parties, but produced no effect. They knew what they were to expect when the thirty days were out; but they knew their commander, and had absolute confidence in his judgment.
Meanwhile, on all sides, the Gauls were responding to the call. From every quarter, even from far-off parts of Belgium, horse and foot were streaming along the roads. Commius of Arras, Caesar's old friend, who had gone with him to Britain, was caught with the same frenzy, and was hastening among the rest to help to end him. At last two hundred and fifty thousand of the