Cæsar had to provide against everything at the same time. It was necessary to raise the purple standard as the signal for hastening to arms,[262] to sound the trumpets to recall the soldiers employed in the works, to bring in those who were at a distance, form the lines, harangue the troops, give the word of order.[263] In this critical situation, the experience of the soldiers, acquired in so many combats, and the presence of the lieutenants with each legion, helped to supply the place of the general, and to enable each to take, by his own impulse, the dispositions he thought best. The impetuosity of the enemy is such that the soldiers have time neither to put on the ensigns,[264] nor to take the covering from their bucklers, nor even to put on their helmets. Each, abandoning his labours, runs to range himself in the utmost haste under the first standard which presents itself. The army, constrained by necessity, was drawn up on the slope of the hill, much more in obedience to the nature of the ground and the exigencies of the moment than according to military rules. The legions, separated from one another by thick hedges, which intercepted their view, could not lend each other mutual succour; they formed an irregular and interrupted line: the 9th and 10th legions were placed on the left of the camp, the 8th and 11th in the centre, the 7th and 12th on the right. In this general confusion, in which it became as difficult to carry succour to the points threatened as to obey one single command, everything was ruled by accident. Cæsar, after taking the measures most urgent, rushes towards the troops which chance presents first to him, takes them as he finds them in his way, harangues them, and, when he comes to the 10th legion, he recalls to its memory, in a few words, its ancient valour. As the enemy was already within reach of the missiles, he orders the attack; then, proceeding towards another point to encourage his troops, he finds them already engaged. The soldiers of the 9th and 10th legions throw the _pilum_, and fall, sword in hand, upon the Atrebates, who, fatigued by their rapid advance, out of breath, and pierced with wounds, are soon driven back from the hill they have just climbed. These two legions, led no doubt by Labienus, drive them into the Sambre, slay a great number, cross the river at their heels, and pursue them up the slopes of the right bank. The enemy, then thinking to take advantage of the commanding position, form again, and renew the combat; but the Romans repulse them anew, and, continuing their victorious march, take possession of the Gaulish camp. In the centre, the 8th and 11th legions, attacked by the Veromandui, had driven them back upon the banks of the Sambre, to the foot of the heights, where the combat still continued.