Titus Livius (Livy), The History of Rome, Book 21
D. Spillan, A.M., M.D., Cyrus Evans, Ed.

29. Whilst the elephants were conveyed over, Hannibal, in the mean time, had sent five hundred Numidian horsemen towards the camp of the Romans, to observe where and how numerous their forces were, and what they were designing. [2] The three hundred Roman horsemen sent, as was before said, from the mouth of the Rhone, meet this band of cavalry; and a more furious engagement than could be expected from the number of the combatants takes place. [3] For, besides many wounds, the loss on both sides was also nearly equal: and the flight and dismay of the Numidians gave victory to the Romans, now exceedingly fatigued. There fell of the conquerors one hundred and sixty, not all Romans, but partly Gauls: of the vanquished more than two hundred. [4] This commencement, and at the same time omen of the war, as it portended to the Romans a prosperous issue of the whole, so did it also the success of a doubtful and by no means bloodless contest. [5] When, after the action had thus occurred, his own men returned to each general, Scipio could adopt no fixed plan of proceeding, except that he should form his measures from the plans and undertakings of the enemy: [6] and Hannibal, uncertain whether he should pursue the march he had commenced [p. 728]into Italy, or fight with the Roman army which had first presented itself, the arrival of ambassadors from the Boii, and of a petty prince called Magalus, diverted from an immediate engagement; who, declaring that they would be the guides of his journey and the companions of his dangers, gave it as their opinion, that Italy ought to be attacked with the entire force of the war, his strength having been no where previously impaired. [7] The troops indeed feared the enemy, the remembrance of the former war not being yet obliterated; but much more did they dread the immense journey and the Alps, a thing formidable by report, particularly to the inexperienced.