Titus Livius (Livy), The History of Rome, Book 28
Cyrus Evans, Ed.

15. The battle was now extremely unequal in every part, both because an irregular band of Balearians and raw Spaniards were opposed to Roman and Latin soldiers, and further, because, as [2??] the day was now getting on, Hasdrubal's troops began to grow languid, having been dispirited by the alarm in the morning, and compelled to go out hastily into the field, without refreshing themselves with food. [3] Scipio had designedly spun out the day, in order that the battle might take place at a late hour; for it was not until the seventh hour that the battalions of infantry charged the wings. [4] It was considerably later before the battle reached the centres, so that the heat from the meridian sun, and the fatigue of standing under arms, together with hunger and thirst, enfeebled their bodies before they engaged the enemy. Thus they stood still, supporting themselves upon their shields. [5] In addition to their other misfortunes, the elephants too, ter- [p. 1182]rified at the tumultuous kind of attack of the cavalry, the skirmishers, and the light-armed, had transferred themselves from the wings to the centre. [6] Fatigued therefore in mind and body, they gave ground, preserving their ranks, however, just as though the army were retreating entire at the command of their general. But when the victors, perceiving that the enemy had given way, charged them on all sides [7??] with increased vehemence on that very account, so that the shock could hardly be sustained, though Hasdrubal endeavoured to stop them and hinder them from retiring, vociferating, “that there were hills on their rear, and a safe refuge if they would retreat without precipitation;” [8] yet, fear getting the better of their sense of shame, and all those who [9??] were nearest the enemy giving way, they immediately turned their backs, and all gave themselves up to disorderly flight. [10] The first place they halted at was the foot of the hills, where they endeavoured to recall the soldiers to their ranks, the Romans hesitating to advance their line up the opposite steep; but afterwards, when they saw them push on briskly, renewing their flight, they were driven into their camp in extreme alarm. [11] Nor were the Romans far from the rampart; and such was their impetuosity, that they would have taken their camp had not so violent a shower of rain suddenly poured down, while, as is usually the case, the solar rays darted with the greatest intensity between the clouds surcharged with water, that the victors with difficulty returned to their camp. Some were even deterred, by superstition, from making any further attempts that day. [12] Though night and the rain invited the Carthaginians to take necessary rest, yet, as their fears and the danger would not allow them to [13??] delay, as it was expected that the enemy would assault their camp as soon as it was light, they raised their rampart by stones collected from the neighbouring valleys around them on all sides, with the determination to defend themselves by works, since there was but little protection in their arms. [14] But the desertion of their allies made it appear safer to fly than stay. Attanes, prince of the Turdetani, began this revolt; he deserted at the head of a numerous band of his countrymen. [15] Then two fortified towns, together with their garrisons, were delivered up by their praefects to the Romans. [16] And, lest the evil should [p. 1183]spread more widely, now that the disposition to revolt from the Carthaginians had evinced itself in one instance, Hasdrubal decamped during the silence of the ensuing night.