Titus Livius (Livy), The History of Rome, Book 22
D. Spillan, A.M., M.D., Cyrus Evans, Ed.

17. As soon as it was dark the camp was moved in silence; the oxen were driven a little in advance of the standards. [2] When they arrived at the foot of the mountains and the narrow passes, the signal is immediately given for setting fire to their horns and driving them violently up the mountains before them. The mere terror excited by the flame, which cast a glare from their heads, and the heat now approaching [p. 785]the quick and the roots of their horns, drove on the oxen as if goaded by madness. [3] By which dispersion, on a sudden all the surrounding shrubs were in a blaze, as if the mountains and woods had been on fire; and the unavailing tossing of their heads quickening the flame, exhibited an appearance as of men running to and fro on every side. [4] Those who had been placed to guard the passage of the wood, when they saw fires on the tops of the mountains, and some over their own heads, concluding that they were surrounded, abandoned their post; making for the tops of the mountains in the direction in which the fewest fires blazed, as being the safest course; however they fell in with some oxen which had strayed from their herds. [5] At first, when they beheld them at a distance, they stood fixed in amazement at the miracle, as it appeared to them, of creatures breathing fire; [6] afterwards, when it showed itself to be a human stratagem, then, forsooth, concluding that there was an ambuscade, as they are hurrying away in flight, with increased alarm, they fall in also with the light-armed troops of the enemy. But the night, when the fear was equally shared, kept them from commencing the battle till morning. [7] Meanwhile Hannibal, having marched his whole army through the pass, and having cut off some of the enemy in the very defile, pitches his camp in the country of Allifae.