Plutarch, Aemilius Paulus
Bernadotte Perrin, Ed.

17. Aemilius, after effecting a junction with Nasica, came down in battle array against the enemy. But when he saw how they were drawn up, and in what numbers, he was amazed, and came to a halt, considering with himself. His young officers, however, who were eager for battle, rode up and begged him not to delay, especially Nasica, who was emboldened by his success at Mount Olympus. [2] But Aemilius, with a smile, said to him: ‘Yes, if I had thy youth; but many victories teach me the mistakes of the vanquished, and forbid me to join battle, immediately after a march, with a phalanx which is already drawn up and completely formed.’ After this, he ordered his foremost troops, who were in sight of the enemy, to form into cohorts and give the appearance of a battle line, while the others, wheeling to the rear, dug trenches and marked out a camp. [3] And in this way, the troops next to the last wheeling off in due succession, before the enemy knew it he had broken up his battle line and brought all his men without confusion into their intrenchments.

Now, when night had come, and the soldiers, after supper, were betaking themselves to rest and sleep, on a sudden the moon, which was full and high in the heavens, grew dark, lost its light, took on all sorts of colours in succession, and finally disappeared. [4] The Romans, according to their custom, tried to call her light back by the clashing of bronze utensils and by holding up many blazing fire-brands and torches towards the heavens; the Macedonians, however, did nothing of this sort, but amazement and terror possessed their camp, and a rumour quietly spread among many of them that the portent signified an eclipse of a king. [5] Now, Aemilius was not altogether without knowledge and experience of the irregularities of eclipses, which, at fixed periods, carry the moon in her course into the shadow of the earth and conceal her from sight, until she passes beyond the region of shadow and reflects again the light of the sun; however, since he was very devout and given to sacrifices and divination, as soon as he saw the moon beginning to emerge from the shadow, he sacrificed eleven heifers to her. [6] And as soon as it was day, he sacrificed as many as twenty oxen to Hercules without getting favourable omens; but with the twenty-first victim the propitious signs appeared and indicated victory if they stood on the defensive. Accordingly, having vowed to the god a hecatomb and solemn games, he ordered his officers to put the army in array for battle; but he himself, waiting for the sun to pass to the west and decline, in order that its morning light might not shine in the faces of his men as they fought, passed the time sitting in his tent, which was open towards the plain and the enemy's encampment.