Titus Livius (Livy), The History of Rome, Book 36
Evan T. Sage, PhD professor of latin and head of the department of classics in the University of Pittsburgh, Ed.

30. Manius Acilius, having sold or given to¹ the soldiers the booty around Heraclea, when he heard that no pacific counsels were being taken at Hypata but that the Aetolians had assembled at Naupactus, that from there they might endure the [2??] whole violence of the war, sent Appius Claudius in advance with four thousand men to hold the ridges where the crossing of the mountains was difficult [3??] and himself climbed Oeta and offered sacrifice to Hercules at the place which they call Pyra,² since there the mortal body of the god had been burned. [4] Then setting out with the entire army he finished the rest of the journey with fairly easy marching; when he came to Corax —this is a very high mountain between Callipolis and Naupactus —there both many animals from the train plunged to the bottom of the gorge, loads and all, and the men were in difficulties; [5] and it was easily seen with how careless an enemy they had to deal, who had not held so difficult a pass with any kind of guard to prevent their crossing. [6] Then too, though his army had suffered, he marched down to Naupactus, and establishing one fort over against the citadel he, dividing his forces as the situation of the walls required, surrounded the other sections of the city. Nor did this siege involve any less toil and labour than that of Heraclea.