+71.+ Now he had some time before remarked a certain piece of ground which was flat and treeless, and yet well suited for an ambush, because there was a stream in it with a high overhanging bank thickly covered with thorns and brambles. Here he determined to entrap the enemy. The place was admirably adapted for putting them off their guard; because the Romans were always suspicious of woods, from the fact of the Celts invariably choosing such places for their ambuscades, but felt no fear at all of places that were level and without trees: not knowing that for the concealment and safety of an ambush such places are much better than woods; because the men can command from them a distant view of all that is going on: while nearly all places have sufficient cover to make concealment possible,—a stream with an overhanging bank, reeds, or ferns, or some sort of bramble-bushes,—which are good enough to hide not infantry only, but sometimes even cavalry, if the simple precaution is taken of laying conspicuous arms flat upon the ground and hiding helmets under shields. Hannibal had confided his idea to his brother Mago and to his council, who had all approved of the plan. Accordingly, when the army had supped, he summoned this young man to his tent, who was full of youthful enthusiasm, and had been trained from boyhood in the art of war, and put under his command a hundred cavalry and the same number of infantry. These men he had himself earlier in the day selected as the most powerful of the whole army, and had ordered to come to his tent after supper. Having addressed and inspired them with the spirit suitable to the occasion, he bade each of them select ten of the bravest men of their own company, and to come with them to a particular spot in the camp. The order having been obeyed, he despatched the whole party, numbering a thousand cavalry and as many infantry, with guides, to the place selected for the ambuscade; and gave his brother directions as to the time at which he was to make the attempt. At daybreak he himself mustered the Numidian cavalry, who were conspicuous for their powers of endurance; and after addressing them, and promising them rewards if they behaved with gallantry, he ordered them to ride up to the enemy’s lines, and then quickly cross the river, and by throwing showers of darts at them tempt them to come out: his object being to get at the enemy before they had had their breakfast, or made any preparations for the day. The other officers of the army also he summoned, and gave them similar instructions for the battle, ordering all their men to get breakfast and to see to their arms and horses. [Sidenote: Battle of the Trebia, December B.C. 218.] [Sidenote: Hannibal’s forces.] [Sidenote: The Roman forces.]