History of the Peloponnesian War

When they had made their preparations, having watched for a stormy night of wind and rain, and at the same time moonless, they went forth under the guidance of those who had been the authors of the enterprise. In the first place then they crossed the ditch which ran round their city, and then came up to the enemy's wall, unperceived by the sentinels; for they did not see before them in the dark, and did not hear them owing to the wind, which drowned with its clatter the noise of their approach;

besides, they went far apart from each other, that their arms might not clash together and betray them. They were also lightly armed, and had only the left foot shod, for security against slipping in the mire.