Titus Livius (Livy), The History of Rome, Book 21
Benjamin Oliver Foster, Ph.D., Ed.

27. Everything was now in readiness for the crossing, which, however, was menaced by the enemy on the other side, who covered the whole bank with their horse and foot. [2] In order to draw them off, Hannibal ordered Hanno, the son of Bomilcar, to set out in the first watch of [3??] the night with a part of the troops, chiefly Spaniards,¹ and, making a march of one day up the stream, to take the first opportunity of crossing it, with the greatest secrecy, and fetch a compass with his column, so that, when the time came, he might assail the enemy in the rear. [4] The Gauls who had been appointed to be his guides informed him that some five-and-twenty miles upstream the river flowed round a little island, and being wider where it divided, and therefore shallower, afforded a passage. There they quickly felled some trees and constructed rafts to transport the men and horses and other burdens. [5] The Spaniards without [p. 79]more ado stuffed their clothes into skins,² and placing³ their bucklers on top of these and supporting themselves by means of them, swam across. The rest of the force, too, got over, by means of the rafts which they had made, and went into camp near the river. [6] They were tired by the night march and their strenuous exertions, but their commander allowed them but one day to rest, being intent on carrying out the stratagem at the proper time. [7] Resuming their march on the following day they sent up a smoke-signal from an elevated place, to show that they had got over the river and were not far off. When Hannibal saw this, he gave the order to cross, so as not to miss the favourable moment. [8] The infantry had their skiffs all ready and equipped, while the cavalry had large boats, for the most part, on account of their horses. The large boats were sent across higher up the stream, to take the force of the current, and provided smooth water for the skiffs that crossed below them. [9] A good part of the horses swam and were towed by their halters from the sterns of the boats, except those which they had saddled and bridled and put on board, that their riders might have them ready for instant use on landing.