Res Gestae

Then the besiegers, pushing before them mantlets and closely-woven hurdles, advanced slowly and cautiously, and with a great number of iron tools tried to undermine the walls. Many carried scaling- ladders made to match the height of the walls, but when they could all but touch the ramparts, some were crushed by stones that were hurled down upon them, others were pierced with whizzing darts; and as the survivors gave way, they carried with them all the rest, whom fear of a like fate turned from their purpose of fighting.