History of the Peloponnesian War

Immediately upon their arrival the Syracusans prepared to attack the Athenians again by land and sea at once. The Athenian generals seeing a fresh army come to the aid of the enemy, and that their own circumstances, far from improving, were becoming daily worse, and above all distressed by the sickness of the soldiers, now began to repent of not having removed before; and Nicias no longer offering the same opposition, except by urging that there should be no open voting, they gave orders as secretly as possible for all to be prepared to sail out from the camp at a given signal.

All was at last ready, and they were on the point of sailing away, when an eclipse of the moon, which was then at the full, took place. Most of the Athenians, deeply impressed by this occurrence, now urged the generals to wait; and Nicias, who was somewhat over-addicted to divination and practices of that kind, refused from that moment even to take the question of departure into consideration, until they had waited the thrice nine days prescribed by the soothsayers.The besiegers were thus condemned to stay in the country;