In accordance with this information, Cæsar sends in this direction, towards the middle of the night, several detachments of cavalry, with orders to scour with great noise the country in every direction at the foot of the heights of Risolles. At break of day, he sends out of the great camp many horses and mules without pack-saddles, and causes the muleteers to mount them, who put on helmets, so as to assume the appearance of mounted troopers. He enjoins them to wind round the hills, and a few cavalry who are joined with them have orders to spread wide over the country, so as to increase the illusion. Finally, they are all, by a long circuit, to move towards the spots which have just been mentioned. These movements were perceived from the town, which overlooked the camp, but at too great a distance to distinguish objects accurately. Cæsar sends towards the same mountain mass one legion, who, after having marched for a short distance, halt in a hollow, and pretend to hide in the woods (towards Chanonat), so as to feign a surprise. The suspicions of the Gauls increase; they take all their forces to the spot threatened. Cæsar, seeing the enemy’s camp deserted, orders the military ensigns (plumes, shields, &c.) to be covered, the standards to be lowered, and the troops to pass in small detachments from the great to the little camp, behind the epaulment of the double fosse of communication, so that they cannot be perceived from the _oppidum_.[493] He communicates his intentions to the lieutenants placed at the heads of the legions, recommends them to take care to prevent the soldiers from allowing themselves to be carried away by the ardour of the combat or the hope of plunder, and draws their attention to the difficulties of the ground. “Celerity alone,” he says, “can enable us to overcome them; in fact, it is to be an attack by surprise, and not a fight.” Having communicated these directions, he gives the signal, and, at the same time, sends the Ædui out of the great camp, with orders to climb the eastern slopes of the mountain of Gergovia, to effect a diversion to the right. (_See Plate 21._)