Titus Livius (Livy), The History of Rome, Book 38
Evan T. Sage, Ph.D., Ed.

26. The consul spent two days in exploring for himself the character of the mountain,¹ that nothing might be unfamiliar to him; on the third day, after giving his attention to the auspices and then offering sacrifice, he divided his army into four columns and led them out, planning to lead two up [2??] the central part of the mountain and to send two from the sides to oppose the flanks of the Gauls. [3] The Tectosagi and the Trocmi, who constituted the [p. 91]strength of the enemy, held the centre of their line² with fifty thousand men; the cavalry, being dismounted since there was no use for horses on the rough cliffs, and numbering ten thousand men, they placed on their right flank; the Cappadocians of Ariarathes and the auxiliaries of Morzius³ on the left flank amounted to about four thousand men. [4] The consul, as at the Olympus mountain, placed the light-armed troops in the van and made provision that there might be at hand an equally large supply of every kind of weapon. [5] When they approached, everything was the same on both sides as in the former battle except courage, which was increased in the victors by reason of their success and diminished in the enemy because, while they themselves had not been conquered, they considered as their own the disaster suffered by men of their own race. [6] And so from like beginnings the affair had the same end. The discharge of a veritable cloud of light missiles overwhelmed the line of the Gauls. [7] No one dared to rush forward from their ranks lest he expose his body to wounds from all sides, and, standing fast, the more closely they were crowded together the more wounds they received, the attackers aiming, so to speak, at a target. [8] The consul, thinking that if he disclosed the standards of the legions to an enemy already disorganized on its own account they would all at once turn to flight, received within his ranks the skirmishers and the rest of the throng of auxiliaries and moved forward his battle-line.